Android bluetooth app crashes while trying to send data via bluetooth. I was able to turn on, make discoverable, and show paired devices. But, it crashes when i attempt the send file button. Im getting these errors in my Debugger.
Process: com.example.bluetooth_demoproject, PID: 31320
java.lang.NullPointerException: Attempt to get length of null
array
at com.example.bluetooth_demoproject.MainActivity.ListDir(MainActivity.java:253)
at com.example.bluetooth_demoproject.MainActivity.onPrepareDialog(MainActivity.java:228)
at android.app.Activity.onPrepareDialog(Activity.java:4000)
at android.app.Activity.showDialog(Activity.java:4063)
at android.app.Activity.showDialog(Activity.java:4014)
at
com.example.bluetooth_demoproject.MainActivity$1.onClick(MainActivity.java:75)
at android.view.View.performClick(View.java:6896)
at
android.widget.TextView.performClick(TextView.java:12689)
at android.view.View$PerformClick.run(View.java:26088)
at android.os.Handler.handleCallback(Handler.java:789)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:164)
at
android.app.ActivityThread.main(ActivityThread.java:6940)
at java.lang.reflect.Method.invoke(Native Method)
at
com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)
Also here is my MainActivity. If theres a better way to sending files via
bluetooth please point it out or help with my code.
public class MainActivity extends Activity {
// Creating objects -----------------------------
private static final int REQUEST_ENABLE_BT = 0;
private static final int REQUEST_DISCOVER_BT_ = 1;
private static int CUSTOM_DIALOG_ID;
ListView dialog_ListView;
TextView mBluetoothStatus, mPairedDevicesList, mTextFolder;
ImageView mBluetoothIcon;
Button mOnButton, mOffButton, mDiscoverableButton, mPairedDevices,
mbuttonOpenDialog, msendBluetooth, mbuttonUp;
File root, fileroot, curFolder;
EditText dataPath;
private static final int DISCOVER_DURATION = 300;
private List<String> fileList = new ArrayList<String>();
// -------------------------------------------------------
BluetoothAdapter mBlueAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dataPath =(EditText) findViewById(R.id.FilePath);
mTextFolder = findViewById(R.id.folder);
mBluetoothStatus = findViewById(R.id.BluetoothStatus);
mBluetoothIcon = findViewById(R.id.bluetoothIcon);
mOnButton = findViewById(R.id.onButton);
mOffButton = findViewById(R.id.offButton);
mDiscoverableButton = findViewById(R.id.discoverableButton);
mPairedDevices = findViewById(R.id.pairedDevices);
mPairedDevicesList = findViewById(R.id.pairedDeviceList);
mbuttonOpenDialog = findViewById(R.id.opendailog);
msendBluetooth = findViewById(R.id.sendBluetooth);
mbuttonUp = findViewById(R.id.up);
mbuttonOpenDialog.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dataPath.setText("");
showDialog(CUSTOM_DIALOG_ID);
}
});
root = new
File(Environment.getExternalStorageDirectory().getAbsolutePath());
curFolder = root;
msendBluetooth.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v) {
sendViaBluetooth();
}
});
//adapter
mBlueAdapter = BluetoothAdapter.getDefaultAdapter();
if(mBlueAdapter == null){
mBluetoothStatus.setText("Bluetooth is not available");
return;
}
else {
mBluetoothStatus.setText("Bluetooth is available");
}
//if Bluetooth isnt enabled, enable it
if (!mBlueAdapter.isEnabled()) {
Intent enableBtIntent = new
Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
//set image according to bluetooth Status
if (mBlueAdapter.isEnabled()) {
mBluetoothIcon.setImageResource(R.drawable.action_on);
}
else {
mBluetoothIcon.setImageResource(R.drawable.action_off);
}
//on button Click
mOnButton.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v) {
if (!mBlueAdapter.isEnabled()) {
showToast("Turning Bluetooth on...");
// intent to on bluetooth
Intent intent = new
Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(intent, REQUEST_ENABLE_BT);
}
else {
showToast("Bluetooth is already on");
}
}
});
//discover Bluetooth button
mDiscoverableButton.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v){
if (!mBlueAdapter.isDiscovering()) {
showToast("Making device discoverable");
Intent intent = new
Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
startActivityForResult(intent, REQUEST_DISCOVER_BT_);
}
}
});
// off button click
mOffButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mBlueAdapter.isEnabled()) {
showToast("Turning Bluetooth off...");
// intent to turn off bluetooth
mBluetoothIcon.setImageResource(R.drawable.action_off);
}
else{
showToast("Bluetooth is already off");
}
}
});
//get paired device button click
mPairedDevices.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mBlueAdapter.isEnabled()) {
mPairedDevices.setText("Paired Devices");
Set<BluetoothDevice> devices =
mBlueAdapter.getBondedDevices();
for (BluetoothDevice device : devices){
mPairedDevices.append("\nDevice: " + device.getName() +
"," + device );
}
}
else {
//bluetooth is off and cant get paired devices
showToast("Turn on bluetooth to get paired devices");
}
}
});
}
#Override
protected Dialog onCreateDialog(int id) {
Dialog dialog = null;
if (id == CUSTOM_DIALOG_ID) {
dialog = new Dialog(MainActivity.this);
dialog.setContentView(R.layout.dailoglayout);
dialog.setTitle("File Selector");
dialog.setCancelable(true);
dialog.setCanceledOnTouchOutside(true);
mTextFolder = (TextView) dialog.findViewById(R.id.folder);
mbuttonUp = (Button) dialog.findViewById(R.id.up);
mbuttonUp.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
ListDir(curFolder.getParentFile());
}
});
dialog_ListView = (ListView) dialog.findViewById(R.id.dialoglist);
dialog_ListView.setOnItemClickListener(new
AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int
position, long id) {
File selected = new File(fileList.get(position));
if (selected.isDirectory()) {
ListDir(selected);
} else if (selected.isFile()) {
getSelectedFile(selected);
} else {
dismissDialog(CUSTOM_DIALOG_ID);
}
}
});
}
return dialog;
}
#Override
protected void onPrepareDialog(int id, Dialog dialog) {
super.onPrepareDialog(id, dialog);
if (id == CUSTOM_DIALOG_ID) {
ListDir(curFolder);
}
}
public void getSelectedFile(File f) {
dataPath.setText(f.getAbsolutePath());
fileList.clear();
dismissDialog(CUSTOM_DIALOG_ID);
}
public void ListDir(File f) {
if (f.equals(root)) {
mbuttonUp.setEnabled(false);
}
else {
mbuttonUp.setEnabled(true);
}
curFolder = f;
mTextFolder.setText(f.getAbsolutePath());
dataPath.setText(f.getAbsolutePath());
File[] files = f.listFiles();
fileList.clear();
for (File file : files) {
fileList.add(file.getPath());
}
ArrayAdapter<String> directoryList = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, fileList);
dialog_ListView.setAdapter(directoryList);
}
// exits to app --------------------------------
public void exit(View V) {
mBlueAdapter.disable();
Toast.makeText(this, "*** Now bluetooth is off...",
Toast.LENGTH_LONG).show();
finish();
}
// send file via bluetooth ------------------------
public void sendViaBluetooth() {
if(!dataPath.equals(null)) {
if(mBlueAdapter == null) {
Toast.makeText(this, "Device doesnt support bluetooth",
Toast.LENGTH_LONG).show();
}
else {
enableBluetooth();
}
}
else {
Toast.makeText(this, "please select a file",
Toast.LENGTH_LONG).show();
}
}
public void enableBluetooth() {
showToast("Making device discoverable");
Intent intent = new
Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
startActivityForResult(intent, REQUEST_DISCOVER_BT_);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent
data) {
if (resultCode == DISCOVER_DURATION && requestCode ==
REQUEST_DISCOVER_BT_) {
Intent i = new Intent();
i.setAction(Intent.ACTION_SEND);
i.setType("*/*");
File file = new File(dataPath.getText().toString());
i.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(file));
PackageManager pm = getPackageManager();
List<ResolveInfo> list = pm.queryIntentActivities(i, 0);
if (list.size() > 0) {
String packageName = null;
String className = null;
boolean found = false;
for (ResolveInfo info : list) {
packageName = info.activityInfo.packageName;
if (packageName.equals("com.android.bluetooth")) {
className = info.activityInfo.name;
found = true;
}
}
//CHECK BLUETOOTH available or not------------------------------
------------------
if (!found) {
Toast.makeText(this, "Bluetooth not been found",
Toast.LENGTH_LONG).show();
} else {
i.setClassName(packageName, className);
startActivity(i);
}
}
} else {
Toast.makeText(this, "Bluetooth is cancelled",
Toast.LENGTH_LONG).show();
}
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
return super.onOptionsItemSelected(item);
}
//toast message function
private void showToast(String msg) {
Toast.makeText(this, msg, Toast.LENGTH_SHORT) .show();
}
}
Related
I created an application which pairs a cellphone to a bluetooth module.
i tested this application with a 4.2 android cellphone and it worked quite well but in cellphones with android higher than 6 the device is not fidning anything when i press " Scan for new devices " button.
but when i go through my phone bluetooth itself, i can find the module i was looking for..
Bluetooth connection class :
public class BluetoothConnectionActivity extends AppCompatActivity {
private ProgressDialog mProgressDlg;
private ArrayList<BluetoothDevice> mDeviceList = new ArrayList<BluetoothDevice>();
private BluetoothAdapter mBluetoothAdapter;
BluetoothDevice device ;
private MediaPlayer mediaplayer = null ;
private Button bluetoothOnOff;
private Button viewpairedDevices;
private Button scanfornewDevices;
private Button blue2;
ImageView unMute;
View view1;
View view2;
private Activity context;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.bluetoothconnectionlayout);
bluetoothOnOff = (Button) findViewById(R.id.bluetoothOnOff);
viewpairedDevices = (Button) findViewById(R.id.viewpairedDevicesButton);
scanfornewDevices = (Button) findViewById(R.id.scanfornewDevicesButton);
blue2 = (Button) findViewById(R.id.bluetoothOnOff2);
view1 = findViewById(R.id.viewFader);
view2 = findViewById(R.id.viewFader2);
unMute = (ImageView) findViewById(R.id.settingStartupSecondary);
mediaplayer = MediaPlayer.create(getApplicationContext(),R.raw.sfxturnon);
Handler startup1 = new Handler();
startup1.postDelayed(new Runnable() {
#Override
public void run() {
view1.animate().alpha(1f).setDuration(500);
view2.animate().alpha(1f).setDuration(500);
}
},1000);
Handler startup2 = new Handler();
startup2.postDelayed(new Runnable() {
#Override
public void run() {
bluetoothOnOff.animate().alpha(1f).setDuration(500);
viewpairedDevices.animate().alpha(1f).setDuration(500);
scanfornewDevices.animate().alpha(1f).setDuration(500);
unMute.animate().alpha(1f).setDuration(100);
}
},1000);
//
// settingBtn.setOnClickListener(new View.OnClickListener() {
// #Override
// public void onClick(View view) {
//
//
// AudioManager amanager=(AudioManager)getSystemService(Context.AUDIO_SERVICE);
// amanager.setStreamMute(AudioManager.STREAM_NOTIFICATION, true);
//
//// settingBtn.setEnabled(false);
//// settingBtn.animate().alpha(0f);
//
// unMute.animate().alpha(1f);
// unMute.setEnabled(true);
//
//
// Toast.makeText(getApplicationContext(), " Application muted. ", Toast.LENGTH_SHORT).show();
//
//
// }
// });
Handler dawg = new Handler();
dawg.postDelayed(new Runnable() {
#Override
public void run() {
bluetoothOnOff.animate().alpha(1f).setDuration(1500);
viewpairedDevices.animate().alpha(1f).setDuration(2500);
scanfornewDevices.animate().alpha(1f).setDuration(3000);
}
},500);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
mProgressDlg = new ProgressDialog(this);
mProgressDlg.setMessage("Scanning, Please wait...");
mProgressDlg.setCancelable(false);
mProgressDlg.setButton(DialogInterface.BUTTON_NEGATIVE, "Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
mBluetoothAdapter.cancelDiscovery();
}
});}
if (mBluetoothAdapter.isEnabled()){
bluetoothOnOff.setText("Bluetooth is On");
blue2.setText("Bluetooth is On");
}else {
blue2.setText("Bluetooth is Off");
bluetoothOnOff.setText("Bluetooth is Off");
}
if (mBluetoothAdapter == null) {
showUnsupported();
} else {
viewpairedDevices.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
if (pairedDevices == null || pairedDevices.size() == 0) {
Toast toast = Toast.makeText(getApplicationContext()," No paired device found.", Toast.LENGTH_SHORT);
View view3 = toast.getView();
view3.setBackgroundColor(Color.parseColor("#ffff5b"));
TextView text = (TextView) view3.findViewById(android.R.id.message);
text.setTextColor(Color.parseColor("#000000"));
toast.show();
} else {
ArrayList<BluetoothDevice> list = new ArrayList<BluetoothDevice>();
list.addAll(pairedDevices);
Intent intent = new Intent(BluetoothConnectionActivity.this, DeviceList.class);
intent.putParcelableArrayListExtra("device.list", list);
startActivity(intent);
}
}
});
scanfornewDevices.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
mBluetoothAdapter.startDiscovery();
}
});
bluetoothOnOff.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (mBluetoothAdapter.isEnabled()) {
mBluetoothAdapter.disable();
showDisabled();
bluetoothOnOff.setText("Bluetooth is OFF");
final Handler handler6 = new Handler();
handler6.postDelayed(new Runnable() {
#Override
public void run() {
mediaplayer.start();
}
}, 500);
final Handler handler3 = new Handler();
handler3.postDelayed(new Runnable() {
#Override
public void run() {
bluetoothOnOff.animate().translationY(-1f).setDuration(5000);
blue2.animate().translationY(-1f).setDuration(5000);
bluetoothOnOff.animate().alpha(1f).setDuration(3000);
blue2.animate().alpha(0f).setDuration(3000);
}
}, 500);
} else {
Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(intent, 1000);
}}
});
blue2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (mBluetoothAdapter.isEnabled()) {
mBluetoothAdapter.disable();
showDisabled();
bluetoothOnOff.setText("Bluetooth is OFF");
final Handler handler6 = new Handler();
handler6.postDelayed(new Runnable() {
#Override
public void run() {
mediaplayer.start();
}
}, 500);
final Handler handler3 = new Handler();
handler3.postDelayed(new Runnable() {
#Override
public void run() {
bluetoothOnOff.animate().translationY(-1f).setDuration(5000);
blue2.animate().translationY(-1f).setDuration(5000);
bluetoothOnOff.animate().alpha(1f).setDuration(3000);
blue2.animate().alpha(0f).setDuration(3000);
}
}, 500);
} else {
Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(intent, 1000);
}}
});
if (mBluetoothAdapter.isEnabled()) {
showEnabled();
} else {
showDisabled();
}
}
IntentFilter filter = new IntentFilter();
filter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
filter.addAction(BluetoothDevice.ACTION_FOUND);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(mReceiver, filter);
}
#Override
public void onPause() {
if (mBluetoothAdapter != null) {
if (mBluetoothAdapter.isDiscovering()) {
mBluetoothAdapter.cancelDiscovery();
}
}
super.onPause();
}
#Override
public void onBackPressed() {
}
#Override
public void onDestroy() {
unregisterReceiver(mReceiver);
super.onDestroy();
}
private void showEnabled() {
bluetoothOnOff.setEnabled(true);
viewpairedDevices.setEnabled(true);
viewpairedDevices.setBackgroundResource(R.drawable.selectorstylish);
scanfornewDevices.setEnabled(true);
scanfornewDevices.setBackgroundResource(R.drawable.selectorstylish);
}
private void showDisabled() {
bluetoothOnOff.setEnabled(true);
viewpairedDevices.setEnabled(false);
viewpairedDevices.setBackgroundResource(R.drawable.selectorstylish);
scanfornewDevices.setEnabled(false);
scanfornewDevices.setBackgroundResource(R.drawable.selectorstylish);
}
private void showUnsupported() {
Toast toast = Toast.makeText(getApplicationContext()," Bluetooth is not supported by this device.", Toast.LENGTH_SHORT);
View view3 = toast.getView();
view3.setBackgroundColor(Color.parseColor("#ffff5b"));
TextView text = (TextView) view3.findViewById(android.R.id.message);
text.setTextColor(Color.parseColor("#000000"));
toast.show();
bluetoothOnOff.setEnabled(false);
viewpairedDevices.setEnabled(false);
viewpairedDevices.setBackgroundResource(R.drawable.selectorstylish);
scanfornewDevices.setEnabled(false);
scanfornewDevices.setBackgroundResource(R.drawable.selectorstylish);
}
private void showToast(String message) {
Toast.makeText(getApplicationContext(), message, Toast.LENGTH_SHORT).show();
}
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothAdapter.ACTION_STATE_CHANGED.equals(action)) {
final int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, BluetoothAdapter.ERROR);
if (state == BluetoothAdapter.STATE_ON) {
bluetoothOnOff.setText("Bluetooth is On");
blue2.setText("Bluetooth is On");
showEnabled();
final Handler handler5 = new Handler();
handler5.postDelayed(new Runnable() {
#Override
public void run() {
mediaplayer.start();
}
}, 500);
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
bluetoothOnOff.animate().translationY(150f).setDuration(5000);
blue2.animate().translationY(150f).setDuration(5000);
bluetoothOnOff.animate().alpha(0f).setDuration(3000);
blue2.animate().alpha(1f).setDuration(3000);
}
}, 500);
}
} else if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
mDeviceList = new ArrayList<BluetoothDevice>();
mProgressDlg.show();
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
mProgressDlg.dismiss();
// Intent newIntent = new Intent(BluetoothConnectionActivity.this, DeviceList.class);
//
// newIntent.putParcelableArrayListExtra("device.list", mDeviceList);
//
// startActivity(newIntent);
} else if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = (BluetoothDevice) intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
mDeviceList.add(device);
Toast toast = Toast.makeText(getApplicationContext()," Found device" + device.getName(), Toast.LENGTH_SHORT);
View view3 = toast.getView();
view3.setBackgroundColor(Color.parseColor("#ffff5b"));
TextView text = (TextView) view3.findViewById(android.R.id.message);
text.setTextColor(Color.parseColor("#000000"));
toast.show();
}
}
};
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.optionmenu,menu);
return super.onCreateOptionsMenu(menu);
}
}
Device list Class :
public class DeviceList extends AppCompatActivity {
private ListView mListView;
private AdapterClassBluetooth mAdapterClassBluetooth;
private ArrayList<BluetoothDevice> mDeviceList;
private BluetoothDevice device ;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_device_list);
mDeviceList = getIntent().getExtras().getParcelableArrayList("device.list");
mListView = (ListView) findViewById(R.id.lv_paired);
mAdapterClassBluetooth = new AdapterClassBluetooth(this);
mAdapterClassBluetooth.setData(mDeviceList);
mAdapterClassBluetooth.setListener(new AdapterClassBluetooth.OnPairButtonClickListener() {
#Override
public void onPairButtonClick(int position) {
BluetoothDevice device = mDeviceList.get(position);
if (device.getBondState() == BluetoothDevice.BOND_BONDED) {
unpairDevice(device);
} else {
Toast toast = Toast.makeText(getApplicationContext(), "Pairing..." , Toast.LENGTH_SHORT);
View view = toast.getView();
view.setBackgroundColor(Color.parseColor("#ffff5b"));
TextView text = (TextView) view.findViewById(android.R.id.message);
text.setTextColor(Color.parseColor("#000000"));
toast.show();
pairDevice(device);
}
}
});
mListView.setAdapter(mAdapterClassBluetooth);
registerReceiver(mPairReceiver, new IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED));
}
#Override
public void onDestroy() {
unregisterReceiver(mPairReceiver);
super.onDestroy();
}
private void showToast(String message) {
Toast.makeText(getApplicationContext(), message, Toast.LENGTH_SHORT).show();
}
private void pairDevice(BluetoothDevice device) {
try {
Method method = device.getClass().getMethod("createBond", (Class[]) null);
method.invoke(device, (Object[]) null);
} catch (Exception e) {
e.printStackTrace();
}
}
private void unpairDevice(BluetoothDevice device) {
try {
Method method = device.getClass().getMethod("removeBond", (Class[]) null);
method.invoke(device, (Object[]) null);
} catch (Exception e) {
e.printStackTrace();
}
}
private final BroadcastReceiver mPairReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_BOND_STATE_CHANGED.equals(action)) {
final int state = intent.getIntExtra(BluetoothDevice.EXTRA_BOND_STATE, BluetoothDevice.ERROR);
final int prevState = intent.getIntExtra(BluetoothDevice.EXTRA_PREVIOUS_BOND_STATE, BluetoothDevice.ERROR);
if (state == BluetoothDevice.BOND_BONDED && prevState == BluetoothDevice.BOND_BONDING) {
Toast toast = Toast.makeText(getApplicationContext()," Device are paired, please wait...", Toast.LENGTH_SHORT);
View view = toast.getView();
view.setBackgroundColor(Color.parseColor("#ffff5b"));
TextView text = (TextView) view.findViewById(android.R.id.message);
text.setTextColor(Color.parseColor("#000000"));
toast.show();
Handler delaying = new Handler();
delaying.postDelayed(new Runnable() {
#Override
public void run() {
Intent communicate = new Intent(DeviceList.this,Security.class);
startActivity(communicate);
finish();
}
},1500);
} else if (state == BluetoothDevice.BOND_NONE && prevState == BluetoothDevice.BOND_BONDED){
Toast toast = Toast.makeText(getApplicationContext(),"Unpaired.", Toast.LENGTH_SHORT);
View view = toast.getView();
view.setBackgroundColor(Color.parseColor("#ffff5b"));
TextView text = (TextView) view.findViewById(android.R.id.message);
text.setTextColor(Color.parseColor("#000000"));
toast.show();
}
mAdapterClassBluetooth.notifyDataSetChanged();
}
}
};}
Adapter class :
public class AdapterClassBluetooth extends BaseAdapter{
private LayoutInflater mInflater;
private List<BluetoothDevice> mData;
private OnPairButtonClickListener mListener;
public AdapterClassBluetooth(){
}
public AdapterClassBluetooth(Context context) {
super();
mInflater = LayoutInflater.from(context);
}
public void setData(List<BluetoothDevice> data) {
mData = data;
}
public void setListener(OnPairButtonClickListener listener) {
mListener = listener;
}
public int getCount() {
return (mData == null) ? 0 : mData.size();
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return position;
}
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.adapterlist, null);
holder = new ViewHolder();
holder.nameTv = (TextView) convertView.findViewById(R.id.tv_name);
holder.addressTv = (TextView) convertView.findViewById(R.id.tv_address);
holder.pairBtn = (Button) convertView.findViewById(R.id.btn_pair);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
BluetoothDevice device = mData.get(position);
holder.nameTv.setText(device.getName());
holder.addressTv.setText(device.getAddress());
holder.pairBtn.setText((device.getBondState() == BluetoothDevice.BOND_BONDED) ? "Unpair" : "Pair");
holder.pairBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mListener != null) {
mListener.onPairButtonClick(position);
}
}
});
return convertView;
}
static class ViewHolder {
TextView nameTv;
TextView addressTv;
TextView pairBtn;
}
public interface OnPairButtonClickListener {
public abstract void onPairButtonClick(int position);
}
}
in an article i studied about this issue and find out that with this code :
if (ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(context,
new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
1);
i can make the application to support phones with android more than 6 so i can discover all nearby devices and pair with them,
The issue is, i don't know where should i exactly use this code..
i would really appreciate if you could tell me where to use it within the codes i showed here.
or simply tell me how to overcome this problem with any other code you may know.
In your AndroidManifest.xml file add this:
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
Then, instead of calling registerReceiver call this function:
private tryRegisterReceiver() {
if (ContextCompat.checkSelfPermission(thisActivity,
Manifest.permission.ACCESS_COARSE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
// Here, permission is not granted
// after calling requestPermissions, the result must be treated in onRequestPermissionResult
ActivityCompat.requestPermissions(thisActivity,
new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
1000); // 100 or other desired code
} else {
// Permission has already been granted
// continue registering your receiver
registerReceiver();
}
}
To treat the result of the permission request
#Override
public void onRequestPermissionsResult(int requestCode,
String[] permissions, int[] grantResults) {
switch (requestCode) {
case 1000: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted
// continue registering your receiver
registerReceiver();
} else {
// permission denied
// show a message or finish your activity
}
return;
}
// other 'case' for other permissions if needed
}
}
I'm trying to create an indoor location services app in android studio.There is a scan button which start the discovery of BLE devices. When i click on the scan button,the app crashes. But when i reopen the app and click on the scan button again,it works.
i tried this taken from one of the projects from stackoverflow.
Class variable:
private BluetoothAdapter mBtAdapter = null;
final BluetoothManager btManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
mBtAdapter = btManager.getAdapter();
if (mBtAdapter == null || !mBtAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
}
public void onScanButton(){
if (mBtAdapter.isEnabled()){
scanLeDevice(true);
}
}
this is my code
BluetoothManager btManager; //field 'btManager' is never used
private BluetoothAdapter btAdapter = null;
BluetoothLeScanner btScanner;
Button startScanningButton;
Button stopScanningButton;
TextView peripheralTextView;
private final static int REQUEST_ENABLE_BT = 1;
private static final int PERMISSION_REQUEST_COARSE_LOCATION = 1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
peripheralTextView = (TextView) findViewById(R.id.peripheralTextView);
peripheralTextView.setMovementMethod(new ScrollingMovementMethod());
startScanningButton = (Button) findViewById(R.id.StartScanButton);
startScanningButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
startScanning();
}
});
stopScanningButton = (Button) findViewById(R.id.StopScanButton);
stopScanningButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
stopScanning();
}
});
stopScanningButton.setVisibility(View.INVISIBLE);
final BluetoothManager btManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
btAdapter = btManager.getAdapter();
btScanner = btAdapter.getBluetoothLeScanner();
if (btAdapter != null && !btAdapter.isEnabled()) {
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent,REQUEST_ENABLE_BT);
}
// Make sure we have access coarse location enabled, if not, prompt the user to enable it
if (this.checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
final AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("This app needs location access");
builder.setMessage("Please grant location access so this app can detect peripherals.");
builder.setPositiveButton(android.R.string.ok, null);
builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
#Override
public void onDismiss(DialogInterface dialog) {
requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, PERMISSION_REQUEST_COARSE_LOCATION);
}
});
builder.show();
}
}
// Device scan callback.
private ScanCallback leScanCallback = new ScanCallback() {
#Override
public void onScanResult(int callbackType, ScanResult result) {
peripheralTextView.append("MAC address: " + result.getDevice().getAddress() + " rssi: " + result.getRssi() + "TxPower:" + result.getTxPower() + "\n");
// auto scroll for text view
final int scrollAmount = peripheralTextView.getLayout().getLineTop(peripheralTextView.getLineCount()) - peripheralTextView.getHeight();
// if there is no need to scroll, scrollAmount will be <=0
if (scrollAmount > 0)
peripheralTextView.scrollTo(0, scrollAmount);
}
};
#Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case PERMISSION_REQUEST_COARSE_LOCATION: {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
System.out.println("coarse location permission granted");
} else {
final AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Functionality limited");
builder.setMessage("Since location access has not been granted, this app will not be able to discover beacons when in the background.");
builder.setPositiveButton(android.R.string.ok, null);
builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
#Override
public void onDismiss(DialogInterface dialog) {
}
});
builder.show();
}
}
}
}
public void startScanning() {
System.out.println("start scanning");
peripheralTextView.setText("");
startScanningButton.setVisibility(View.INVISIBLE);
stopScanningButton.setVisibility(View.VISIBLE);
AsyncTask.execute(new Runnable() {
#Override
public void run() {
btScanner.startScan(leScanCallback);
}
});
}
public void stopScanning() {
System.out.println("stopping scanning");
peripheralTextView.append("Stopped Scanning");
startScanningButton.setVisibility(View.VISIBLE);
stopScanningButton.setVisibility(View.INVISIBLE);
AsyncTask.execute(new Runnable() {
#Override
public void run() {
btScanner.stopScan(leScanCallback);
}
});
}
}
The logcat shows
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.bluetooth.le.BluetoothLeScanner.startScan(android.bluetooth.le.ScanCallback)' on a null object reference
at com.example.myapplication.MainActivity$6.run(MainActivity.java:137)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.lang.Thread.run(Thread.java:764)
Before i click the Scan button,a prompt will be display asking to turn
on the bluetooth.So bluetooth will be turned on
You are wrong about that part. You ask the user to enable it, but it might not have happened yet. At least you need to get the Scanner later on.
Currently you set the Scanner reference before the permission requesting has been initiated.
This also explains why it works after your App has crashed for the first time, because the 2nd time you come here the Permission has been enabled.
From the Javadoc of BluetoothAdapter#getBluetoothLeScanner():
Will return null if Bluetooth is turned off or if Bluetooth LE
Advertising is not supported on this device.
You can change your code to:
public void startScanning() {
btScanner = btAdapter.getBluetoothLeScanner();
if (btScanner == null) {
// not enabled yet or not supported
return;
}
System.out.println("start scanning");
peripheralTextView.setText("");
startScanningButton.setVisibility(View.INVISIBLE);
stopScanningButton.setVisibility(View.VISIBLE);
AsyncTask.execute(new Runnable() {
#Override
public void run() {
btScanner.startScan(leScanCallback);
}
});
}
For some reason, the repeat and shuffle buttons are not doing anything.
The buttons previous and next work perfectly.
In my app I am communicating with my service through broadcasts.
mediaPlayer is a public static in my service class and I am importing it in other activity.
public static MediaPlayer mediaPlayer = new MediaPlayer(); (In Service.class)
Activity
This is the code for the buttons
if (mediaPlayer != null) {
if (mediaPlayer.isPlaying()) {
mBtnPlayPause.setImageResource(R.drawable.ic_action_pause_white);
tvSongListSize.setText((songIndex + 1) + "/" + songList.size());
updateProgressBar();
}
}
mBtnShuffle.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (isShuffle){
isShuffle = false;
Toast.makeText(getContext(), "Shuffle is off", Toast.LENGTH_SHORT ).show();
mBtnShuffle.setImageResource(R.drawable.ic_action_shuffle);
}else{
isShuffle = true;
Toast.makeText(getContext(), "Shuffle is on", Toast.LENGTH_SHORT).show();
mBtnShuffle.setImageResource(R.drawable.ic_shuffle_on);
isRepeat = false;
mBtnRepeat.setImageResource(R.drawable.ic_action_repeat);
}
}
});
mBtnRepeat.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (isRepeat){
isRepeat = false;
Toast.makeText(getContext(), "Repeat is off", Toast.LENGTH_SHORT).show();
mBtnRepeat.setImageResource(R.drawable.ic_action_repeat);
}else{
isRepeat = true;
Toast.makeText(getContext(), "Repeat is on", Toast.LENGTH_SHORT).show();
mBtnRepeat.setImageResource(R.drawable.ic_repeat_on);
isShuffle = false;
mBtnShuffle.setImageResource(R.drawable.ic_action_shuffle);
}
}
});
mBtnPlayPause.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
if (mediaPlayer != null) {
if (mediaPlayer.isPlaying()) {
mediaPlayer.pause();
mBtnPlayPause.setImageResource(R.drawable.ic_action_play);
} else {
mediaPlayer.start();
mBtnPlayPause.setImageResource(R.drawable.ic_action_pause_white);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
});
mBtnNext.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
nextSong();
}
});
mBtnPrev.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
prevSong();
}
});
Code in onCompletionListener
#Override
public void onCompletion(MediaPlayer mp) {
if (isRepeat){
//Store current songIndex in mSharedPreferences
StorageUtil storageUtil = new StorageUtil(getContext());
storageUtil.storeSongIndex(songIndex);
//Send media with BroadcastReceiver
Intent broadCastReceiverIntent = new Intent(Constants.ACTIONS.BROADCAST_PlAY_NEW_SONG);
if (getActivity() != null) {
getActivity().sendBroadcast(broadCastReceiverIntent);
}
}else if(isShuffle){
Random random = new Random();
songIndex = random.nextInt((songList.size() - 1) + 1);
tvSongListSize.setText((songIndex + 1) + "/" + songList.size());
//Store random songIndex in mSharedPreferences
StorageUtil storageUtil = new StorageUtil(getContext());
storageUtil.storeSongIndex(songIndex);
//Send media with BroadcastReceiver
Intent broadCastReceiverIntent = new Intent(Constants.ACTIONS.BROADCAST_PlAY_NEW_SONG);
if (getActivity() != null) {
getActivity().sendBroadcast(broadCastReceiverIntent);
}
}else if (songIndex < songList.size()-1){
mediaPlayer.reset();
nextSong();
tvSongListSize.setText((songIndex + 1) + "/" + songList.size());
}else{
songIndex = 0;
tvSongListSize.setText((1) + "/" + songList.size());
//Store random songIndex in mSharedPreferences
StorageUtil storageUtil = new StorageUtil(getContext());
storageUtil.storeSongIndex(songIndex);
//Send media with BroadcastReceiver
Intent broadCastReceiverIntent = new Intent(Constants.ACTIONS.BROADCAST_PlAY_NEW_SONG);
if (getActivity() != null) {
getActivity().sendBroadcast(broadCastReceiverIntent);
}
}
}
Broadcast receiver
private BroadcastReceiver NewSongBroadCastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
songList = new StorageUtil(getApplicationContext()).getSongs();
songIndex = new StorageUtil(getApplicationContext()).loadSongIndex();
if (songIndex != -1 && songIndex < songList.size()){
activeSong = songList.get(songIndex);
}else{
stopSelf();
}
stopSong();
mediaPlayer.reset();
if (mMediaSessionManager == null) {
try {
initMediaSession();
initMediaPlayer();
} catch (RemoteException e) {
e.printStackTrace();
stopSelf();
}
}
initMediaPlayer();
updateMetaData();
NotificationBuilder(PlaybackStatus.PLAYING);
}
};
The buttons mBtnShuffle and mBtnRepeat do not trigger onCompletion. They are just 2 ordinary buttons that you use to set the flags isShuffle and isRepeat.
onCompletion is triggered when a song has been completed.
So if you want something to happen when the 2 buttons are tapped you should put some code in their listeners.
I'm trying to used sharedpreferences for when a user chooses a specific custom image they want in their storage for a part of a grid of images. I want the image they chose to show up even after they close the application and reopen it. The problem I'm having is that the sharedpreferences don't seem to be working. Nothing shows up as the background image for the grid item they've selected once they've closed the app or even just pressed the back button.
Do I have to create a sharedpreferences file myself? I can't figure out how to get to it or create one if so using androidstudio.
Here's my code for the class (Sorry if it's long and messy...I am new to coding and still testing things):
public class editCreations extends Activity {
public int mPosition = 0;
protected static Sounds sound = new Sounds();
private static int RESULT_LOAD_IMAGE = 1;
private MediaRecorder mRecorder;
private MediaPlayer mPlayer;
private String mOutputFile = Environment.getExternalStorageDirectory().getAbsolutePath();
private Drawable mImageFileName;
private Button recordBtn;
private Button stopBtn;
private Button playBtn;
private Button stopPlayBtn;
private ImageButton imgBtn;
private Drawable bg;
private String mPicturePath;
private ImageAdapter img = new ImageAdapter(this);
View.OnClickListener playListener = new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(editCreations.this, "test", Toast.LENGTH_SHORT);
}
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create);
mRecorder = new MediaRecorder();
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mRecorder.setAudioEncoder(MediaRecorder.OutputFormat.AMR_NB);
mRecorder.setOutputFile(mOutputFile);
recordBtn = (Button)findViewById(R.id.create_record_button);
recordBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
start(view);
}
});
stopBtn = (Button)findViewById(R.id.create_stop_record_button);
stopBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
stop(view);
}
});
playBtn = (Button)findViewById(R.id.create_play_button);
playBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
play(view);
}
});
stopPlayBtn = (Button)findViewById(R.id.create_stop_button);
stopPlayBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
stopPlay(view);
}
});
imgBtn = (ImageButton)findViewById(R.id.imageButton);
Intent extra = getIntent();
Bundle extras = extra.getExtras();
// gave mPosition a default int to debug and find problem -> found it
mPosition = extras.getInt("position");
getSelectedFile(mPosition);
imgBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent i = new Intent(
Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, RESULT_LOAD_IMAGE);
}
});
}
public void start (View view) {
try {
mRecorder.prepare();
mRecorder.start();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
recordBtn.setEnabled(false);
stopBtn.setEnabled(true);
Toast.makeText(editCreations.this, mPosition + "!", Toast.LENGTH_SHORT).show();
}
public void stop(View view){
try {
mRecorder.stop();
mRecorder.release();
mRecorder = null;
stopBtn.setEnabled(false);
recordBtn.setEnabled(true);
Toast.makeText(getApplicationContext(), "Stop recording...",
Toast.LENGTH_SHORT).show();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (RuntimeException e) {
e.printStackTrace();
}
}
public void play(View view) {
try{
mPlayer = new MediaPlayer();
mPlayer.setDataSource(mOutputFile);
mPlayer.prepare();
mPlayer.start();
playBtn.setEnabled(false);
stopPlayBtn.setEnabled(true);
Toast.makeText(getApplicationContext(), "Start play the recording...",
Toast.LENGTH_SHORT).show();
} catch (Exception e) {
e.printStackTrace();
}
}
public void stopPlay(View view) {
try {
if (mPlayer != null) {
mPlayer.stop();
mPlayer.release();
mPlayer = null;
playBtn.setEnabled(true);
stopPlayBtn.setEnabled(false);
Toast.makeText(getApplicationContext(), "Stop playing the recording...",
Toast.LENGTH_SHORT).show();
}
} catch (Exception e){
e.printStackTrace();
}
}
public void getSoundPosition(int position) {
mOutputFile = mOutputFile + "/Lollatone_clip_" + mPosition + ".3gpp";
// use to get proper image and sound files and edit output file to proper name
}
public void getSelectedFile(int position) {
switch (mPosition) {
case 0:
imgBtn.setBackgroundResource(R.drawable.sample_0);
imgBtn.refreshDrawableState();
break;
case 1:
imgBtn.setImageBitmap(BitmapFactory.decodeFile(mPicturePath));
imgBtn.refreshDrawableState();
break;
case 2:
imgBtn.setImageBitmap(BitmapFactory.decodeFile(mPicturePath));
imgBtn.refreshDrawableState();
break;
case 3:
imgBtn.setImageBitmap(BitmapFactory.decodeFile(mPicturePath));
imgBtn.refreshDrawableState();
break;
case 4:
imgBtn.setBackgroundResource(R.drawable.sample_4);
imgBtn.refreshDrawableState();
break;
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.edit_creations, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode,resultCode,data);
if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && null != data) {
Uri selectedImage = data.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA};
Cursor cursor = getContentResolver().query(selectedImage,
filePathColumn, null,null,null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
mPicturePath = cursor.getString(columnIndex);
cursor.close();
imgBtn.setImageBitmap(BitmapFactory.decodeFile(mPicturePath));
imgBtn.refreshDrawableState();
// String picturePath contains the path of
// selected image
}
}
protected void onPause() {
super.onPause();
//need an editor object to make preference changes
// all objects are from android.context.Context
SharedPreferences sharedPref = getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putString("img_" + mPosition, mPicturePath);
editor.commit();
}
protected void onResume() {
super.onResume();
SharedPreferences sharedPref = getPreferences(Context.MODE_PRIVATE);
mPicturePath = sharedPref.getString("img_" + mPosition, "img_" + mPosition);
}
}
You are using SharedPreferences correctly but you are not placing the code in the right activity lifecycle methods. You are reading the preference on onCreate() and saving on onStop() so maybe what you can do it save the preference on onPause() (to make sure it gets saved earlier) and reload on onResume() instead of onCreate() (the latter only occurs once in the life cycle of an activity).
Also, you might want to check if Context.getSharedPreferences() would be a better choice for this, since it's shared between more than just one activity.
I want to integrate my Google map with Facebook SDK to check in location via Facebook and share it out in the same layout but when I add this code to method onCreate(), it's force close and tell an errors
if (savedInstanceState == null) {
// Add the fragment on initial activity setup
mainFragment = new MainFragment();
getSupportFragmentManager().beginTransaction().add(android.R.id.content, mainFragment).commit();
myFragmentManager = getSupportFragmentManager();
mainFragment = (MainFragment) myFragmentManager.findFragmentById(R.id.checkIn);
} else {
// Or set the fragment from restored state info
mainFragment = (MainFragment) getSupportFragmentManager().findFragmentById(android.R.id.content);
}
and here is my onCreate() method
protected void onCreate(final Bundle savedInstanceState) {
try {
// Permission StrictMode
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
}
super.onCreate(savedInstanceState);
setContentView(R.layout.check_in);
checkInButton = (Button) findViewById(R.id.shareButton);
checkInButton.setVisibility(View.VISIBLE);
authButton = (Button)findViewById(R.id.authButton);
authButton.setVisibility(View.VISIBLE);
endLocationEditText = (EditText) findViewById(R.id.endLocationEditText);
endLocationEditText.setVisibility(View.INVISIBLE);
startLocationEdittext = (EditText) findViewById(R.id.starLocationEditText);
startLocationEdittext.setVisibility(View.INVISIBLE);
toggle = (ToggleButton) findViewById(R.id.togglebutton);
toggle.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if (hasConnection(getApplicationContext()) == true) {
if (toggle.isChecked()) {
endLocationEditText = (EditText) findViewById(R.id.endLocationEditText);
endLocationEditText.setVisibility(View.VISIBLE);
startLocationEdittext = (EditText) findViewById(R.id.starLocationEditText);
startLocationEdittext.setVisibility(View.INVISIBLE);
goButton.setVisibility(View.VISIBLE);
} else {
endLocationEditText = (EditText) findViewById(R.id.endLocationEditText);
endLocationEditText.setVisibility(View.INVISIBLE);
startLocationEdittext = (EditText) findViewById(R.id.starLocationEditText);
startLocationEdittext.setVisibility(View.VISIBLE);
goButton.setVisibility(View.VISIBLE);
}
checkInButton.setVisibility(View.VISIBLE);
checkInButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
endLocationEditText
.setVisibility(View.INVISIBLE);
AlertDialog.Builder builder = new AlertDialog.Builder(
CheckIn.this);
builder.setTitle("Attach photo?");
builder.setNegativeButton("No",
new DialogInterface.OnClickListener() {
public void onClick(
DialogInterface dialog,
int which) {
}
});
builder.setPositiveButton("Yes",
new DialogInterface.OnClickListener() {
public void onClick(
DialogInterface dialog,
int which) {
Intent captureIntent = new Intent(
MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(
captureIntent,
CAMERA_CAPTURE);
}
});
builder.show();
}
});
} else {
System.out.println("ยังไม่ได้ต่อเน็ต");
AlertDialog.Builder builder = new AlertDialog.Builder(
CheckIn.this);
builder.setTitle("Please connect to the Internet.");
builder.show();
}
}
});
goButton = (Button) findViewById(R.id.goButton);
goButton.setVisibility(View.INVISIBLE);
goButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if (toggle.isChecked() == true) {
String location = endLocationEditText.getText()
.toString();
if (location != null && !location.equals("")) {
new GeocoderTask().execute(location);
}
} else {
String location = startLocationEdittext.getText()
.toString();
if (location != null && !location.equals("")) {
new GeocoderTask().execute(location);
}
}
}
});
myLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
String provider = myLocationManager.getBestProvider(criteria, true);
Location location = myLocationManager
.getLastKnownLocation(provider);
if (location != null) {
onLocationChanged(location);
}
myLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 20000, 0, this);
// สำหรับแสดง Google maps v2
FragmentManager myFragmentManager = getSupportFragmentManager();
SupportMapFragment mySupportMapFragment = (SupportMapFragment) myFragmentManager
.findFragmentById(R.id.checkIn);
myMap = mySupportMapFragment.getMap();
myMap.setMyLocationEnabled(true);
fromMarkerPosition = new LatLng(location.getLatitude(),
location.getLongitude());
toMarkerPosition = fromMarkerPosition;
myMap.animateCamera(CameraUpdateFactory.newLatLngZoom(
fromMarkerPosition, 13));
myMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
myMap.addMarker(new MarkerOptions()
.position(fromMarkerPosition)
.title("Yor are here!")
.icon(BitmapDescriptorFactory
.defaultMarker(BitmapDescriptorFactory.HUE_AZURE)));
myMap.getUiSettings().setCompassEnabled(true);
myMap.getUiSettings().setZoomControlsEnabled(true);
/* จบการแสดง maps */
// สร้าง click event สำหรับระบุพิกัดจุด
myMap.setOnMapClickListener(new OnMapClickListener() {
public void onMapClick(LatLng arg0) {
if (hasConnection(getApplicationContext()) == true) {
final LatLng coordinate = arg0;
AlertDialog.Builder builder = new AlertDialog.Builder(
CheckIn.this);
endLocationEditText.setVisibility(View.INVISIBLE);
startLocationEdittext.setVisibility(View.INVISIBLE);
goButton.setVisibility(View.INVISIBLE);
System.out
.println("#####################################################");
builder.setTitle("Select Marker").setItems(
new String[] { "From", "To" },
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int position) {
try {
if (position == 0) {
fromMarkerPosition = coordinate;
System.out
.println(fromMarkerPosition
+ " yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy");
refreshMarker();
} else if (position == 1) {
toMarkerPosition = coordinate;
System.out
.println(toMarkerPosition
+ " ttttttttttttttttttttttttttttttttttttttt");
refreshMarker();
}
} catch (Exception ex) {
ex.printStackTrace();
System.out
.println("Please connect to the internet first");
}
}
});
builder.show();
myMap.animateCamera(CameraUpdateFactory
.newLatLng(coordinate));
checkInButton.setVisibility(View.VISIBLE);
checkInButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
endLocationEditText
.setVisibility(View.INVISIBLE);
AlertDialog.Builder builder = new AlertDialog.Builder(
CheckIn.this);
builder.setTitle("Attach photo?");
builder.setNegativeButton("No",
new DialogInterface.OnClickListener() {
public void onClick(
DialogInterface dialog,
int which) {
}
});
builder.setPositiveButton("Yes",
new DialogInterface.OnClickListener() {
public void onClick(
DialogInterface dialog,
int which) {
Intent captureIntent = new Intent(
MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(
captureIntent,
CAMERA_CAPTURE);
}
});
builder.show();
}
});
} else {
System.out.println("ยังไม่ได้ต่อเน็ต");
AlertDialog.Builder builder = new AlertDialog.Builder(
CheckIn.this);
builder.setTitle("Please connect to the Internet.");
builder.show();
}
}
});
if (savedInstanceState == null) {
// Add the fragment on initial activity setup
mainFragment = new MainFragment();
getSupportFragmentManager().beginTransaction().add(android.R.id.content, mainFragment).commit();
myFragmentManager = getSupportFragmentManager();
mainFragment = (MainFragment) myFragmentManager
.findFragmentById(R.id.checkIn);
} else {
// Or set the fragment from restored state info
mainFragment = (MainFragment) getSupportFragmentManager()
.findFragmentById(android.R.id.content);
}
} catch (Exception ex) {
ex.printStackTrace();
}
}// end onCreate
here is my MainFragment class........
public class MainFragment extends Fragment{
private static final List<String> PERMISSIONS = Arrays.asList("publish_actions");
private static final String PENDING_PUBLISH_KEY = "pendingPublishReauthorization";
private boolean pendingPublishReauthorization = false;
private Button shareButton;
private UiLifecycleHelper uiHelper;
private static final String TAG = "MainFragment";
private Session.StatusCallback callback = new Session.StatusCallback() {
#Override
public void call(Session session, SessionState state, Exception exception) {
onSessionStateChange(session, state, exception);
}
};
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
uiHelper = new UiLifecycleHelper(getActivity(), callback);
uiHelper.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.check_in, container, false);
LoginButton authButton = (LoginButton) view.findViewById(R.id.authButton);
authButton.setFragment(this);
authButton.setReadPermissions(Arrays.asList("user_likes", "user_status"));
shareButton = (Button) view.findViewById(R.id.shareButton);
shareButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
publishStory();
}
});
if (savedInstanceState != null) {
pendingPublishReauthorization =
savedInstanceState.getBoolean(PENDING_PUBLISH_KEY, false);
}
return view;
}
private void onSessionStateChange(Session session, SessionState state, Exception exception) {
if (state.isOpened()) {
Log.i(TAG, "Logged in...");
} else if (state.isClosed()) {
Log.i(TAG, "Logged out...");
}
if (state.isOpened()) {
shareButton.setVisibility(View.VISIBLE);
if (pendingPublishReauthorization &&
state.equals(SessionState.OPENED_TOKEN_UPDATED)) {
pendingPublishReauthorization = false;
publishStory();
}
} else if (state.isClosed()) {
shareButton.setVisibility(View.INVISIBLE);
}
}
private void publishStory() {
Session session = Session.getActiveSession();
if (session != null){
// Check for publish permissions
List<String> permissions = session.getPermissions();
if (!isSubsetOf(PERMISSIONS, permissions)) {
pendingPublishReauthorization = true;
Session.NewPermissionsRequest newPermissionsRequest = new Session
.NewPermissionsRequest(this, PERMISSIONS);
session.requestNewPublishPermissions(newPermissionsRequest);
return;
}
Bundle postParams = new Bundle();
postParams.putString("name", "Facebook SDK for Android");
postParams.putString("caption", "Build great social apps and get more installs.");
postParams.putString("description", "The Facebook SDK for Android makes it easier and faster to develop Facebook integrated Android apps.");
postParams.putString("link", "https://developers.facebook.com/android");
postParams.putString("picture", "https://raw.github.com/fbsamples/ios-3.x-howtos/master/Images/iossdk_logo.png");
Request.Callback callback= new Request.Callback() {
public void onCompleted(Response response) {
JSONObject graphResponse = response
.getGraphObject()
.getInnerJSONObject();
String postId = null;
try {
postId = graphResponse.getString("id");
} catch (JSONException e) {
Log.i(TAG,
"JSON error "+ e.getMessage());
}
FacebookRequestError error = response.getError();
if (error != null) {
Toast.makeText(getActivity()
.getApplicationContext(),
error.getErrorMessage(),
Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getActivity()
.getApplicationContext(),
postId,
Toast.LENGTH_LONG).show();
}
}
};
Request request = new Request(session, "me/feed", postParams,
HttpMethod.POST, callback);
RequestAsyncTask task = new RequestAsyncTask(request);
task.execute();
}
}
private boolean isSubsetOf(Collection<String> subset, Collection<String> superset) {
for (String string : subset) {
if (!superset.contains(string)) {
return false;
}
}
return true;
}
#Override
public void onResume() {
super.onResume();
Session session = Session.getActiveSession();
if (session != null &&
(session.isOpened() || session.isClosed()) ) {
onSessionStateChange(session, session.getState(), null);
}
uiHelper.onResume();
}
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
uiHelper.onActivityResult(requestCode, resultCode, data);
}
#Override
public void onPause() {
super.onPause();
uiHelper.onPause();
}
#Override
public void onDestroy() {
super.onDestroy();
uiHelper.onDestroy();
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putBoolean(PENDING_PUBLISH_KEY, pendingPublishReauthorization);
uiHelper.onSaveInstanceState(outState);
}
}
xml line 8 is here
<fragment
android:id="#+id/checkIn"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/authButton"
class="com.google.android.gms.maps.SupportMapFragment" />
here is an Errors
03-09 20:17:15.433: E/AndroidRuntime(12547): Caused by: android.view.InflateException: Binary XML file line #8: Error inflating class fragment
03-09 20:17:15.433: E/AndroidRuntime(12547): Caused by: java.lang.IllegalArgumentException: Binary XML file line #8: Duplicate id 0x7f04000a, tag null, or parent id 0x0 with another fragment for com.google.android.gms.maps.SupportMapFragment
Take a look at http://code.google.com/p/gmaps-api-issues/issues/detail?id=5064#c1 for how to put SupportMapFragment inside fragment correctly.