I am working on an Android App that lets me create an Event in CreateActivity, and than passes the data from CreateActivity to the MainActivity through Bundle and putExtras().
It appears as if I am using .getExtras() or getString() wrong. The app crashes once the b.getString("TITLE") function is implemented.
public class MainActivity extends FragmentActivity implements OnClickListener {
ListView listView;
int lastIndex = -1;
ArrayList<Event> lstEvents;
// detail view
TextView tvTitle, tvTime, tvDate;
ImageView img;
View vw_master;
boolean _isBack = true;
ImageButton add;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
// get list view
listView = (ListView) findViewById(R.id.listViewFragment);
lstEvents = new ArrayList<Event>();
// // get detail controls
tvTitle = (TextView) findViewById(R.id.textViewTitle);
tvDate = (TextView) findViewById(R.id.textViewDate);
tvTime = (TextView) findViewById(R.id.textViewTime);
Bundle b = this.getIntent().getExtras();
b.getString("TITLE");
add = (ImageButton) findViewById(R.id.add);
add.setOnClickListener(this);
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.add:
Intent intent = new Intent(this, CreateActivity.class);
startActivity(intent);
break;
}
}
}
CREATEACTIVITY
public class CreateActivity extends Activity implements OnClickListener {
EditText etTitle;
Button btDate;
Button btTime;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
// /onclicklistener
findViewById(R.id.btn_confirm).setOnClickListener(this);
// edittexts and buttons
btDate = (Button) findViewById(R.id.btn_date);
etTitle = (EditText) findViewById(R.id.editTextTitle);
btTime = (Button) findViewById(R.id.btn_time);
}
// Will be called via the onClick attribute
// of the buttons in main.xml
public void onClick(View view) {
switch (view.getId()) {
case R.id.btn_confirm:
String title = etTitle.getText().toString();
String time = btTime.getText().toString();
String date = btDate.getText().toString();
Log.e("LOG", title);
Log.e("LOG", time);
Log.e("LOG", date);
Bundle newBundle = new Bundle();
newBundle.putString("TITLE", title);
newBundle.putString("TIME", time);
newBundle.putString("DATE", date);
Intent intent = new Intent(this, MainActivity.class);
intent.putExtras(newBundle);
startActivity(intent);
break;
}
}
public void showTimePickerDialog(View v) {
DialogFragment newFragment = new TimePickerFragment();
newFragment.show(getFragmentManager(), "timePicker");
}
public void showDatePickerDialog(View v) {
DialogFragment newFragment = new DatePickerFragment();
newFragment.show(getFragmentManager(), "datePicker");
}
}
Error Log :
03-03 15:44:07.117: E/AndroidRuntime(15202): FATAL EXCEPTION: main
03-03 15:44:07.117: E/AndroidRuntime(15202): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.datetracker/com.example.datetracker.MainActivity}: java.lang.NullPointerException
03-03 15:44:07.117: E/AndroidRuntime(15202): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2202)
03-03 15:44:07.117: E/AndroidRuntime(15202): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2252)
03-03 15:44:07.117: E/AndroidRuntime(15202): at android.app.ActivityThread.access$600(ActivityThread.java:146)
03-03 15:44:07.117: E/AndroidRuntime(15202): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1240)
03-03 15:44:07.117: E/AndroidRuntime(15202): at android.os.Handler.dispatchMessage(Handler.java:99)
03-03 15:44:07.117: E/AndroidRuntime(15202): at android.os.Looper.loop(Looper.java:137)
03-03 15:44:07.117: E/AndroidRuntime(15202): at android.app.ActivityThread.main(ActivityThread.java:5168)
03-03 15:44:07.117: E/AndroidRuntime(15202): at java.lang.reflect.Method.invokeNative(Native Method)
03-03 15:44:07.117: E/AndroidRuntime(15202): at java.lang.reflect.Method.invoke(Method.java:511)
03-03 15:44:07.117: E/AndroidRuntime(15202): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:797)
03-03 15:44:07.117: E/AndroidRuntime(15202): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:564)
03-03 15:44:07.117: E/AndroidRuntime(15202): at dalvik.system.NativeStart.main(Native Method)
03-03 15:44:07.117: E/AndroidRuntime(15202): Caused by: java.lang.NullPointerException
03-03 15:44:07.117: E/AndroidRuntime(15202): at com.example.datetracker.MainActivity.onCreate(MainActivity.java:47)
03-03 15:44:07.117: E/AndroidRuntime(15202): at android.app.Activity.performCreate(Activity.java:5200)
03-03 15:44:07.117: E/AndroidRuntime(15202): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
03-03 15:44:07.117: E/AndroidRuntime(15202): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2166)
I figured out that the problem was being caused from the fact that when the app is initially opened it is trying to getExtras() on values that haven't been placed yet.
I used this as a simple fix to check if there is any extras at first launch.
Intent intent = getIntent();
if (intent.getExtras() == null) {
// Do first time stuff here
} else {
// Do stuff with intent data here
Bundle b = getIntent().getExtras();
title = b.getString("TITLE");
time = b.getString("TIME");
date = b.getString("DATE");
}
I think the problem is you didn't initialize lstEvents.
Let's try lstEvents = new ArrayList<Event>() in onCreate() methods
You should declare all your variables inside onCreate() method!!!
public class WebsiteActivity extends AppCompatActivity {
#SuppressLint("SetJavaScriptEnabled")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_website);
WebView webView;
Intent intent = getIntent();
String website = intent.getStringExtra("key");
//Open website
webView = findViewById(R.id.webViewId);
webView.getSettings().setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient());
webView.loadUrl(website);
}
}
My guess would be that in this line:
Integer id = eventItem.get_Id();
get_Id() is returning null, based on the observation that you aren't initializing that field in the new Event() calls and that you haven't gotten into the habit of initializing variable instances yet.
Given that, you'd be passing in null to the view.setId(id) call. When you do initialiaze it, don't initialize it to 0 as that's not a valid Id for views. you can use NO_ID or a positive number.
Also:
in onCreate()
You can check that findViewById(R.id.add) is returning a View and not null. That would cause a NullPointerException at about the right line of code.
Related
I am learning android development and i have a problem displaying contact detail in my app.
When I click an item of contact activity, the app hangs.
Could you help me please?
This is the activity App of Contact List.
public class ListViewActivity3 extends AppCompatActivity {
ListView listView;
List<ContactHelper> listAdapter;
public static final String Key_Postion = "keyPosition" ;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list_view3);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
listAdapter = new ArrayList<ContactHelper>();
listAdapter.clear();
listAdapter.add(new ContactHelper("achref", "Tunisien", "2222222", R.drawable.imagesand));
listAdapter.add(new ContactHelper("achref", "Tunisien", "2222222", R.drawable.imagesand));
listAdapter.add(new ContactHelper("achref", "Tunisien", "2222222", R.drawable.imagesand));
listAdapter.add(new ContactHelper("achref", "Tunisien", "2222222", R.drawable.imagesand));
listAdapter.add(new ContactHelper("achref", "Tunisien", "2222222", R.drawable.imagesand));
listView = (ListView) findViewById(R.id.listviewCustomAdapter);
listView.setAdapter(new AdapterCustom(ListViewActivity3.this, R.layout.listviewitem1, listAdapter));
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent i3 = new Intent(ListViewActivity3.this, ContactDetailItem.class);
i3.putExtra(Key_Postion, position);
startActivity(i3);
}
});
}
}
and this the ConatctDetailItem
public class ContactDetailItem extends AppCompatActivity {
TextView n, ph, surn;
ImageView imgC;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_contact_detail_item);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
n = (TextView) findViewById(R.id.contactName);
surn = (TextView) findViewById(R.id.contactSurname);
ph = (TextView) findViewById(R.id.contactPhone);
imgC = (ImageView) findViewById(R.id.imgContact);
Bundle bundle = getIntent().getExtras();
if (bundle != null) {
ContactHelper contactHelper = new ContactHelper();
ListViewActivity3 lv = new ListViewActivity3();
int position = bundle.getInt(ListViewActivity3.Key_Postion);
n.setText(lv.listAdapter.get(position).getName());
surn.setText(lv.listAdapter.get(position).getSurname());
ph.setText(lv.listAdapter.get(position).getPhone());
imgC.setImageResource(lv.listAdapter.get(position).getPhoto());
}
}
}
Here is the logcat.
com.example.achre.activityapp E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.achre.activityapp/com.example.achre.activityapp.ContactDetailItem}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
at android.app.ActivityThread.access$600(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5041)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.achre.activityapp.ContactDetailItem.onCreate(ContactDetailItem.java:50)
at android.app.Activity.performCreate(Activity.java:5104)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
at android.app.ActivityThread.access$600(ActivityThread.java:141)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5041)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)
In ContactDetailItem you are creating new ListViewActivity3. Instead it put to extra ContactHelper object.
Change your code like this:
Intent i3 = new Intent(ListViewActivity3.this, ContactDetailItem.class);
i3.putExtra(Key_Postion, listAdapter.get(position));
startActivity(i3);
and in ContactDetailItem:
ContactHelper contactHelper = (ContactHelper) bundle.getSerializableExtra(ListViewActivity3.Key_Postion);
n.setText(contactHelper.getName());
// ...
also your ContactHelper class must implement Serializable interface
When trying to move to another activity the app crashes...
logcat
java.lang.RuntimeException: Unable to start activity ComponentInfo{myact.julianhernandez.com.counterapp/myact.julianhernandez.com.counterapp.CounterDisplay}: android.content.res.Resources$NotFoundException: String resource ID #0x0
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x0
at android.content.res.Resources.getText(Resources.java:244)
at android.widget.TextView.setText(TextView.java:3888)
at myact.julianhernandez.com.counterapp.CounterDisplay.onCreate(CounterDisplay.java:31)
at android.app.Activity.performCreate(Activity.java:5231)
MainActivity.class Code
public class MainActivity extends AppCompatActivity {
Button moveActivity;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
moveActivity = (Button) findViewById(R.id.list1_button);
moveActivity.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent toCounter = new Intent(MainActivity.this , CounterDisplay.class);
startActivity(toCounter);
}
});
CounterDisplay.class Code
public class CounterDisplay extends AppCompatActivity {
private TextView countView;
private Button addButton;
private Button subtractButton;
//int initialCount = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_counter_display);
countView = (TextView) findViewById(R.id.currentCount);
addButton = (Button) findViewById(R.id.add);
subtractButton = (Button) findViewById(R.id.subtract);
countView.setText(0);
//increment counter by 1
addButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int currentCount;// = initialCount;
for(currentCount=0;currentCount>=0;currentCount++){
countView.setText(currentCount);
}
}
});
}
}
Why does this code crash when switching activities?
Textview.setText(int) method takes a resource ID, not the text you are trying to display. Because there are no resource strings matching the ID you pass in (which is 0 on line 31), an exception gets thrown.
There are additional overloads of the setText() method that allow you to pass in a char[] if you don't want to use resource strings. View the documentation for more information. http://developer.android.com/reference/android/widget/TextView.html
I’m using Sherlock library and I want to create a tab in my app but I’m getting a NullPointerException; what am I doing wrong?
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.bonsitesherlock/com.example.bonsitesherlock.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2077)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2104)
at android.app.ActivityThread.access$600(ActivityThread.java:134)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1247)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:4624)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:809)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at android.widget.TabHost.addTab(TabHost.java:229)
at com.example.bonsitesherlock.MainActivity.addTab(MainActivity.java:49)
at com.example.bonsitesherlock.MainActivity.setTabs(MainActivity.java:32)
at com.example.bonsitesherlock.MainActivity.onCreate(MainActivity.java:27)
at android.app.Activity.performCreate(Activity.java:4479)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1050)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2041)
... 11 more
This is my MainActivity:
public class MainActivity extends SherlockActivity {
private TabHost mTabHost;
ProgressDialog pDialog;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTabHost = (TabHost)findViewById(android.R.id.tabhost);
setTabs();
}
private void setTabs()
{
addTab("", R.drawable.tab_news, News.class);
addTab("", R.drawable.tab_servises, News.class);
addTab("", R.drawable.tab_profile, News.class);
}
private void addTab(String labelId, int drawableId, Class<?> c)
{
Intent intent = new Intent(getApplicationContext(), c);
TabHost.TabSpec spec = mTabHost.newTabSpec("tab" + labelId);
View tabIndicator = LayoutInflater.from(this).inflate(R.layout.tab_indicator, mTabHost.getTabWidget(), false);
TextView title = (TextView) tabIndicator.findViewById(R.id.title);
title.setText(labelId);
ImageView icon = (ImageView) tabIndicator.findViewById(R.id.icon);
icon.setImageResource(drawableId);
spec.setIndicator(tabIndicator);
spec.setContent(intent);
mTabHost.addTab(spec);
}
}
I try to intercept outgoing calls and open a pop up
(Receiver --> FragmentActivity --> PopUpFragment)
Im using roboguice for android
however my code crashes with this error:
01-01 10:32:41.396 13265-13265/com.example.stopcall.app E/﹕ mali: REVISION=Linux-r3p2-01rel3 BUILD_DATE=Fri Mar 21 13:52:50 KST 2014
01-01 10:32:41.931 13265-13265/com.example.stopcall.app E/ActivityThread﹕ Performing stop of activity that is not resumed: {com.example.stopcall.app/com.example.stopcall.app.activities.MainActivity}
java.lang.RuntimeException: Performing stop of activity that is not resumed: {com.example.stopcall.app/com.example.stopcall.app.activities.MainActivity}
at android.app.ActivityThread.performStopActivityInner(ActivityThread.java:3463)
at android.app.ActivityThread.handleStopActivity(ActivityThread.java:3550)
at android.app.ActivityThread.access$1200(ActivityThread.java:175)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1335)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5602)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
at dalvik.system.NativeStart.main(Native Method)
here is my code:
public class OutgoingCallReceiver extends RoboBroadcastReceiver {
public static final String ABORT_PHONE_NUMBER = "0055";
private static final String OUTGOING_CALL_ACTION = "android.intent.action.NEW_OUTGOING_CALL";
private static final String INTENT_PHONE_NUMBER = "android.intent.extra.PHONE_NUMBER";
#Override
protected void handleReceive(Context context, Intent intent) {
super.handleReceive(context, intent);
Intent i = new Intent(context, PopupActivity.class);
i.putExtra(Constants.DIALED_PHONE, phoneDal.getItem(phoneNumber));
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);
setResultData(null);
}
and
public class PopupActivity extends RoboFragmentActivity implements
YesNoDialogFragment.YesNoDialogFragmentListener {
#Inject PhoneDal phoneDal;
public Phone phone;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.activity_main);
//
// btnEditName = (Button) findViewById(R.id.btn_edit);
// txtName = (TextView) findViewById(R.id.txt_name);
//
// btnEditName.setOnClickListener(this);
phone = getIntent().getParcelableExtra(Constants.DIALED_PHONE);
exportDatabase(Constants.DB_NAME);
showYesNoDialog();
}
// The dialog fragment receives a reference to this Activity through the
// Fragment.onAttach() callback, which it uses to call the following methods
// defined by the NoticeDialogFragment.NoticeDialogListener interface
#Override
public void onDialogPositiveClick() {
persistNumberIsAllowed();
SendDialIntent();
finish();
}
private void SendDialIntent() {
Intent intent = new Intent(Intent.ACTION_DIAL);
intent.setData(Uri.parse("tel" + phone.phone));
startActivity(intent);
}
In my android application , I have 3 dialogue boxes in which the user puts info into 3 editTexts and it will display the one of the data onto another class/page after it randomly picks which data to choose.
This is my mainClass
public class MainActivity extends Activity {
//Variables are displayed in this area
String choices[] = new String[3];
//EditText editText;
//EditText editText2;
//EditText editText3;
Button mainButton ;
Random rand = new Random();
int finalChoice;
String displayChoice = "";
EditText editText ;
EditText editText2;
EditText editText3;
EditText editText4;
String test;
int count = 3;
//--------------------------- --------------------------------------------------------
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//Makes Button
setContentView(R.layout.activity_main);
declareTextBox();
setButton();
String choice1 = editText.getText().toString();
String choice2 = editText2.getText().toString();
String choice3 = editText3.getText().toString();
choices[0] = choice1; //pass from click button to method.
choices[1] = choice2;
choices[2] = choice3;
finalChoice =rand.nextInt(2);
}
public void setButton()
{
final Button mainbutton = (Button) findViewById(R.id.mainButton);
mainbutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
test = ((EditText) findViewById(R.id.editText4)).getText().toString();
// count++;
//retChoice();
// loadScreen();
Intent i = new Intent(MainActivity.this, resultScreen.class);
i.putExtra("display" , displayChoice);
Intent intent = new Intent(MainActivity.this,loadingScreen.class);
//start the second Activity
MainActivity.this.startActivity(intent);
}
});
}
public void declareTextBox()
{
editText = (EditText) findViewById(R.id.editText1);
editText2 = (EditText) findViewById(R.id.editText2);
editText3 = (EditText) findViewById(R.id.editText3);
}
public void getString(String finalChoice)
{
finalChoice = displayChoice;
}
public String retChoice()
{
displayChoice = choices[finalChoice];
return displayChoice;
}
public void clearText()
{
editText.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
editText.setText(" ");
}
});
editText2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
editText2.setText(" ");
}
});
editText3.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
editText3.setText(" ");
}
});
}
public void getText2()
{
}
public void getText()
{
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
This is my Display class :
public class resultScreen extends Activity {
MainActivity ma = new MainActivity();
//Method supposedly retrieves the string data from MainActivity Class but somehow displayed null instead.
//Find a way to keep the string variable when transfering from one class to another class.
String finalResult = ma.retChoice();
public void onCreate(Bundle resultScreen){
super.onCreate(resultScreen);
setContentView(R.layout.resultscreen);
//ma.displayChoice.toString();
String str = finalResult;
TextView text = (TextView) findViewById(R.id.textView1);
text.setText(str);
final Button backbutton = (Button) findViewById(R.id.backButton);
backbutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v)
{
Intent intent = new Intent(resultScreen.this,MainActivity.class);
resultScreen.this.startActivity(intent);
}
});
}
}
And this is my loading screen class right after the main button is clicked
public class loadingScreen extends Activity{
protected void onCreate(Bundle loadingScreen) {
// TODO Auto-generated method stub
super.onCreate(loadingScreen);
setContentView(R.layout.loadingscreen);
//If sound clip 20 sec long we don't want to carryit outside next class
// A timer thread looking for "run" method
Thread timer = new Thread()
{
public void run() {
try {
//this is how many mil sec
sleep(8000);
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
Intent intent = new Intent(loadingScreen.this, resultScreen.class);
loadingScreen.this.startActivity(intent);
loadingScreen.this.finish();
}
}
};
timer.start();
}
}
My app crashes a few seconds into the loading screen when the program attempts to display the data on the resultScreen.
Here's my logCat
05-17 22:32:54.446: D/AndroidRuntime(1181): Shutting down VM
05-17 22:32:54.446: W/dalvikvm(1181): threadid=1: thread exiting with uncaught exception (group=0x40a70930)
05-17 22:32:54.636: E/AndroidRuntime(1181): FATAL EXCEPTION: main
05-17 22:32:54.636: E/AndroidRuntime(1181): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.choiceprototest/com.example.choiceprototest.resultScreen}: java.lang.NullPointerException
05-17 22:32:54.636: E/AndroidRuntime(1181): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2106)
05-17 22:32:54.636: E/AndroidRuntime(1181): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
05-17 22:32:54.636: E/AndroidRuntime(1181): at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-17 22:32:54.636: E/AndroidRuntime(1181): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
05-17 22:32:54.636: E/AndroidRuntime(1181): at android.os.Handler.dispatchMessage(Handler.java:99)
05-17 22:32:54.636: E/AndroidRuntime(1181): at android.os.Looper.loop(Looper.java:137)
05-17 22:32:54.636: E/AndroidRuntime(1181): at android.app.ActivityThread.main(ActivityThread.java:5039)
05-17 22:32:54.636: E/AndroidRuntime(1181): at java.lang.reflect.Method.invokeNative(Native Method)
05-17 22:32:54.636: E/AndroidRuntime(1181): at java.lang.reflect.Method.invoke(Method.java:511)
05-17 22:32:54.636: E/AndroidRuntime(1181): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-17 22:32:54.636: E/AndroidRuntime(1181): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-17 22:32:54.636: E/AndroidRuntime(1181): at dalvik.system.NativeStart.main(Native Method)
05-17 22:32:54.636: E/AndroidRuntime(1181): Caused by: java.lang.NullPointerException
05-17 22:32:54.636: E/AndroidRuntime(1181): at com.example.choiceprototest.MainActivity.retChoice(MainActivity.java:101)
05-17 22:32:54.636: E/AndroidRuntime(1181): at com.example.choiceprototest.resultScreen.<init>(resultScreen.java:18)
05-17 22:32:54.636: E/AndroidRuntime(1181): at java.lang.Class.newInstanceImpl(Native Method)
05-17 22:32:54.636: E/AndroidRuntime(1181): at java.lang.Class.newInstance(Class.java:1319)
05-17 22:32:54.636: E/AndroidRuntime(1181): at android.app.Instrumentation.newActivity(Instrumentation.java:1054)
05-17 22:32:54.636: E/AndroidRuntime(1181): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2097)
05-17 22:32:54.636: E/AndroidRuntime(1181): ... 11 more
05-17 22:33:03.385: I/Process(1181): Sending signal. PID: 1181 SIG: 9
05-17 22:33:05.435: E/Trace(1204): error opening trace file: No such file or directory (2)
Thanks guys.
I believe I see the problem. You are trying to access your Array but it is an instance variable instead of static so it is being killed off when you exit your Activity. You can either put them in a static class and access them that way or pass a String variable through your Intent, depending on what you need.
If you have the value of the String you need when you leave MainActivity then I would probably just pass it through your Intent. If the value depended on something in one of your other Activities then I would consider putting it in a separate class but it doesn't look like that's what you need here
Edit
You are already doing it here, kind of
Intent i = new Intent(MainActivity.this, resultScreen.class);
i.putExtra("display" , displayChoice);
Intent intent = new Intent(MainActivity.this,loadingScreen.class);
But you aren't starting the Activity that would get the String
i.putExtra("display" , displayChoice);
that line would pass a String with key "displpay" and value of displayChoice, although I think that value is an empty String at that point, but you don't start that Activity. I'm lost on how your flow is suppose to work but basically you would do something like this
String displayChoice = "testValue"; // some arbitrary value--whatever you need to send
Intent i = new Intent(MainActivity.this, resultScreen.class); // create the Intent
i.putExtra("display" , displayChoice); // add the extra
startActivity(i); //start the Activity
then to get the value inside resultScreen in onCreate()
Intent recIntent = getIntent(); // get the Intent that started this Activity
String value = recIntent.getStringExtra("display"); // get the value using the key
// value now equals "testValue"
I think your app chash because you have an ANR: "Application Not Responding" because you are running a long procces inside the UIThread. (onCreate() method is form the UIThread)
Use rather as an Asyntack for your sleeping thread or one handler (with messages).
If you need more I can edit your code tomorrow.