Can someone point me out the error in this code. I am learning to code and I was trying to run my first app from tutorial I saw, until I found this message "Unfortunately, The New Boston has stopped". This the message I get when every time I tried to open it after installation. I even tried on three different phone and in my Emulator and the same thing happened. I looked at my code and I found no error on any line of code. And then I tried to debug it. Here is the entire code and the logcat report respectively.
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import android.os.Build;
public class MainActivity extends ActionBarActivity {
int counter;
Button add,sub;
TextView display;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
add = (Button) findViewById(R.id.bAdd);
add = (Button) findViewById(R.id.sSub);
display = (TextView) findViewById(R.id.tvDisplat);
add.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
counter++;
display.setText("Your total is" + counter);
}
});
sub.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
counter--;
display.setText("Your total is" + counter);
}
});
}
}
#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;
}
#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);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
Logcat output
07-18 21:28:21.047: E/AndroidRuntime(10601): FATAL EXCEPTION: main
07-18 21:28:21.047: E/AndroidRuntime(10601): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.thenewbostone/com.thenewbostone.MainActivity}: java.lang.NullPointerException
07-18 21:28:21.047: E/AndroidRuntime(10601): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
07-18 21:28:21.047: E/AndroidRuntime(10601): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
07-18 21:28:21.047: E/AndroidRuntime(10601): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
07-18 21:28:21.047: E/AndroidRuntime(10601): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
07-18 21:28:21.047: E/AndroidRuntime(10601): at android.os.Handler.dispatchMessage(Handler.java:99)
07-18 21:28:21.047: E/AndroidRuntime(10601): at android.os.Looper.loop(Looper.java:123)
07-18 21:28:21.047: E/AndroidRuntime(10601): at android.app.ActivityThread.main(ActivityThread.java:4627)
07-18 21:28:21.047: E/AndroidRuntime(10601): at java.lang.reflect.Method.invokeNative(Native Method)
07-18 21:28:21.047: E/AndroidRuntime(10601): at java.lang.reflect.Method.invoke(Method.java:521)
07-18 21:28:21.047: E/AndroidRuntime(10601): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:871)
07-18 21:28:21.047: E/AndroidRuntime(10601): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:629)
07-18 21:28:21.047: E/AndroidRuntime(10601): at dalvik.system.NativeStart.main(Native Method)
07-18 21:28:21.047: E/AndroidRuntime(10601): Caused by: java.lang.NullPointerException
07-18 21:28:21.047: E/AndroidRuntime(10601): at com.thenewbostone.MainActivity.onCreate(MainActivity.java:34)
07-18 21:28:21.047: E/AndroidRuntime(10601): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-18 21:28:21.047: E/AndroidRuntime(10601): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
07-18 21:28:21.047: E/AndroidRuntime(10601): ... 11 more
You just have problem with this, sub should be on the second line, not add.
add = (Button) findViewById(R.id.bAdd);
add = (Button) findViewById(R.id.sSub);
So, it crashes then on this line
sub.setOnClickListener(new View.OnClickListener() {
cause sub wasn't initialized.
Related
I tried to create a simple listview. I've done it many times & this is the first time i face such errors. Tried this in both Eclipse Luna & indigo. Both have the same error.
Here is where i create an instant of the adapter :
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;
public class ActivityMain extends Activity {
public ArrayList<StructRemedy> remedies = new ArrayList<StructRemedy>();
private ListView lstContent;
public AdapterRemedy adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lstContent = (ListView) findViewById(R.id.lstContent);
adapter = new AdapterRemedy(remedies);
randomPopulation();
lstContent.setAdapter(adapter);
}
private void randomPopulation() {
for (int i = 0; i < 30; i++) {
StructRemedy remedy = new StructRemedy();
remedy.title = "Remedy" + i;
remedy.description = "Desc" + i;
remedy.rateValue = (float) (Math.random() * 5);
remedy.type = "tisane";
remedy.use = "Headaches";
remedies.add(remedy);
}
adapter.notifyDataSetChanged();
}
}
Now the error log (The error referes to the line where i create the constructor , u know the "super" line) :
06-08 10:03:27.875: E/AndroidRuntime(2715): FATAL EXCEPTION: main
06-08 10:03:27.875: E/AndroidRuntime(2715): java.lang.RuntimeException: Unable to start activity ComponentInfo{ahmad.azimi.app.herbal_remedies/test.test1.app.herbal_remedies.ActivityMain}: java.lang.NullPointerException
06-08 10:03:27.875: E/AndroidRuntime(2715): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
06-08 10:03:27.875: E/AndroidRuntime(2715): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
06-08 10:03:27.875: E/AndroidRuntime(2715): at android.app.ActivityThread.access$600(ActivityThread.java:141)
06-08 10:03:27.875: E/AndroidRuntime(2715): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
06-08 10:03:27.875: E/AndroidRuntime(2715): at android.os.Handler.dispatchMessage(Handler.java:99)
06-08 10:03:27.875: E/AndroidRuntime(2715): at android.os.Looper.loop(Looper.java:137)
06-08 10:03:27.875: E/AndroidRuntime(2715): at android.app.ActivityThread.main(ActivityThread.java:5041)
06-08 10:03:27.875: E/AndroidRuntime(2715): at java.lang.reflect.Method.invokeNative(Native Method)
06-08 10:03:27.875: E/AndroidRuntime(2715): at java.lang.reflect.Method.invoke(Method.java:511)
06-08 10:03:27.875: E/AndroidRuntime(2715): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
06-08 10:03:27.875: E/AndroidRuntime(2715): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
06-08 10:03:27.875: E/AndroidRuntime(2715): at dalvik.system.NativeStart.main(Native Method)
06-08 10:03:27.875: E/AndroidRuntime(2715): Caused by: java.lang.NullPointerException
06-08 10:03:27.875: E/AndroidRuntime(2715): at android.widget.ArrayAdapter.init(ArrayAdapter.java:310)
06-08 10:03:27.875: E/AndroidRuntime(2715): at android.widget.ArrayAdapter.<init>(ArrayAdapter.java:153)
06-08 10:03:27.875: E/AndroidRuntime(2715): at test.test1.app.herbal_remedies.AdapterRemedy.<init>(AdapterRemedy.java:22)
06-08 10:03:27.875: E/AndroidRuntime(2715): at test.test1.app.herbal_remedies.ActivityMain.onCreate(ActivityMain.java:22)
06-08 10:03:27.875: E/AndroidRuntime(2715): at android.app.Activity.performCreate(Activity.java:5104)
06-08 10:03:27.875: E/AndroidRuntime(2715): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
06-08 10:03:27.875: E/AndroidRuntime(2715): at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
This is the adapter :
import java.util.ArrayList;
import android.content.Intent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.RatingBar;
import android.widget.TextView;
public class AdapterRemedy extends ArrayAdapter<StructRemedy> {
public AdapterRemedy(ArrayList<StructRemedy> remedies) {
super(G.context, R.layout.adapter_notes, remedies);
}
private static class ViewHolder {
public TextView txtTitle;
public TextView txtType;
public TextView txtFor;
public RatingBar rating;
public ViewGroup layoutRoot;
public ImageView imgLogo;
public ViewHolder(View view) {
layoutRoot = (ViewGroup) view.findViewById(R.id.layoutRoot);
txtTitle = (TextView) view.findViewById(R.id.txtTitle);
txtType = (TextView) view.findViewById(R.id.txtType);
txtFor = (TextView) view.findViewById(R.id.txtFor);
rating = (RatingBar) view.findViewById(R.id.rate);
imgLogo = (ImageView) view.findViewById(R.id.imgLogo);
}
public void fill(final ArrayAdapter<StructRemedy> adapter, final StructRemedy item, final int position) {
txtTitle.setText(item.title);
txtType.setText(item.type);
txtFor.setText(item.use);
rating.setRating(item.rateValue);
//imgLogo.setImageBitmap(bm);
layoutRoot.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(G.currentActivity, ActivitySelect.class);
intent.putExtra("POSITION", position);
G.currentActivity.startActivity(intent);
}
});
}
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
StructRemedy item = getItem(position);
if (convertView == null) {
convertView = G.inflater.inflate(R.layout.adapter_notes, parent, false);
holder = new ViewHolder(convertView);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.fill(this, item, position);
return convertView;
}
}
Try this :
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lstContent = (ListView) findViewById(R.id.lstContent);
randomPopulation();
}
Put adapter = new AdapterRemedy (remedies ) ; after randomPopulation. Or set adapter in randomPopulation method.
And remove adapter.notifyDataSetchanged() from randomPopulation.
Do some changes in your adapter code :
public AdapterRemedy(ArrayList<StructRemedy> remedies) {
super(G.context, R.layout.adapter_notes, remedies);
}
Change it to this :
public AdapterRemedy(context,ArrayList<StructRemedy> remedies) {
super(context, R.layout.adapter_notes, remedies);
}
And in randomPopulation :
adapter = new AdapterRemedy(this,remedies);
lstContent.setAdapter(adapter);
adapter.notifyDataSetChanged();
Change your onCreate() like ,
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lstContent = (ListView) findViewById(R.id.lstContent);
randomPopulation();
adapter = new AdapterRemedy(remedies);
lstContent.setAdapter(adapter);
}
Call randomPopulation() before the adater Initialization. remove
adapter.notifyDataSetChanged();
I'm working with a listview which on click opens a dialog box which contains an edittext and a button. On button click, the value entered in the editText is saved in a textView from listview item which had been pressed before. The problem is that the value wasn't saved anymore if I reopened the application. I tried to make it save using sharedPrefences but it's crashing and shows 3 nullpointerexception and can't deal with them.
Here is my:
Carnet.java
package com.cngcnasaud.orar;
import android.app.TabActivity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TabHost;
import android.widget.TabHost.TabSpec;
#SuppressWarnings("deprecation")
public class Carnet extends TabActivity {
// TabSpec Names
private static final String NOTA_SPEC = "Note";
private static final String ABSENTE_SPEC = "Absente";
private static final String MEDII_SPEC = "Medii";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.carnet);
TabHost tabHost = getTabHost();
TabSpec NotaSpec = tabHost.newTabSpec(NOTA_SPEC);
// Tab Icon
NotaSpec.setIndicator(NOTA_SPEC, getResources().getDrawable(R.drawable.nota_open));
Intent notaIntent = new Intent(this, Note.class);
// Tab Content
NotaSpec.setContent(notaIntent);
TabSpec AbsenteSpec = tabHost.newTabSpec(ABSENTE_SPEC);
AbsenteSpec.setIndicator(ABSENTE_SPEC, getResources().getDrawable(R.drawable.nota_open));
Intent absenteIntent = new Intent(this, Absente.class);
AbsenteSpec.setContent(absenteIntent);
TabSpec MediiSpec = tabHost.newTabSpec(MEDII_SPEC);
AbsenteSpec.setIndicator(MEDII_SPEC, getResources().getDrawable(R.drawable.nota_open));
Intent mediiIntent = new Intent(this, MediiL.class);
AbsenteSpec.setContent(mediiIntent);
// Adding all TabSpec to TabHost
tabHost.addTab(NotaSpec);
tabHost.addTab(AbsenteSpec);
tabHost.addTab(MediiSpec);
}
}
Note.java
package com.cngcnasaud.orar;
import java.util.ArrayList;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.view.Menu;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class Note extends Activity {
private static final ListAdapter NoteAdapter = null;
ListView lv;
Context context;
ArrayList<?> prgmName;
TextView text;
public static String[] prgmNameList = { "Romana - ", "Matematica - ",
"Lb. Engleza - ", "Lb. Germana/Franceza - ", "Istorie - ",
"Geografie - ", "Biologie - ", "Fizica - ", "Ed. Fizica - " };
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.note_listview);
text = (TextView) findViewById(R.id.textView2);
context = this;
lv = (ListView) findViewById(R.id.listView);
lv.setAdapter(new NoteAdapter(this, prgmNameList, null));
}
#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;
}
#Override
protected void onStop() {
// TODO Auto-generated method stub
NoteAdapter adapter = (NoteAdapter) lv.getAdapter();
// Variable is public for clarity.
String toSave = EncodeDecode.encode(adapter.savedEntries);
SharedPreferences.Editor editor = getSharedPreferences("LV Data",
MODE_PRIVATE).edit();
editor.putString("TVEntries", toSave);
editor.commit();
}
#Override
protected void onResume() {
// TODO Auto-generated method stub
SharedPreferences prefs = getSharedPreferences("LV Data", MODE_PRIVATE);
String encoded = prefs.getString("TVEntries", "");
String[] entries;
if (encoded.equals(""))
entries = null;
else
entries = EncodeDecode.decode(encoded);
NoteAdapter adapter = (NoteAdapter) lv.getAdapter();
adapter.savedEntries = entries;
lv.setAdapter(adapter);
super.onResume();
}
}
And NoteAdapter.java:
package com.cngcnasaud.orar;
import java.util.Arrays;
import android.app.Dialog;
import android.content.Context;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
public class NoteAdapter extends BaseAdapter {
String[] result;
Context context;
int[] imageId;
private static LayoutInflater inflater = null;
private Dialog dialog;
String[] savedEntries;
String[] saved = null;
public NoteAdapter(Note note, String[] saved, String[] prgmNameList) {
// TODO Auto-generated constructor stub
result = prgmNameList;
context = note;
inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (saved == null) {
savedEntries = new String[result.length];
Arrays.fill(savedEntries, "");
} else
savedEntries = saved;
}
#Override
public int getCount() {
// TODO Auto-generated method stub
return result.length;
}
#Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return savedEntries[position];
}
#Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
public class Holder {
TextView tv;
ImageView img;
public TextView text;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
final Holder holder = new Holder();
View rowView;
rowView = inflater.inflate(R.layout.note_items, null);
holder.tv = (TextView) rowView.findViewById(R.id.textView1);
holder.text = (TextView) rowView.findViewById(R.id.textView2);
holder.text.setText(savedEntries[position]);
holder.img = (ImageView) rowView.findViewById(R.id.imageView1);
rowView.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
dialog = new Dialog(context);
dialog.setContentView(R.layout.dialog);
dialog.setTitle("Materie:" + result[position]);
final EditText txtMode = (EditText) dialog
.findViewById(R.id.dialog);
Button btnSave = (Button) dialog.findViewById(R.id.bsave);
btnSave.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
String data = txtMode.getText().toString();
holder.text.setText(data);
savedEntries[position] = data;
dialog.dismiss();
Log.d("data", data);
}
});
dialog.show();
}
});
return rowView;
}
}
logcat:
04-18 19:27:28.558: E/AndroidRuntime(1419): FATAL EXCEPTION: main
04-18 19:27:28.558: E/AndroidRuntime(1419): Process: com.cngcnasaud.orar, PID: 1419
04-18 19:27:28.558: E/AndroidRuntime(1419): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.cngcnasaud.orar/com.cngcnasaud.orar.Carnet}: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.cngcnasaud.orar/com.cngcnasaud.orar.Note}: java.lang.NullPointerException
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.os.Handler.dispatchMessage(Handler.java:102)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.os.Looper.loop(Looper.java:136)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.ActivityThread.main(ActivityThread.java:5017)
04-18 19:27:28.558: E/AndroidRuntime(1419): at java.lang.reflect.Method.invokeNative(Native Method)
04-18 19:27:28.558: E/AndroidRuntime(1419): at java.lang.reflect.Method.invoke(Method.java:515)
04-18 19:27:28.558: E/AndroidRuntime(1419): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-18 19:27:28.558: E/AndroidRuntime(1419): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-18 19:27:28.558: E/AndroidRuntime(1419): at dalvik.system.NativeStart.main(Native Method)
04-18 19:27:28.558: E/AndroidRuntime(1419): Caused by: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.cngcnasaud.orar/com.cngcnasaud.orar.Note}: java.lang.NullPointerException
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.ActivityThread.startActivityNow(ActivityThread.java:2035)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:135)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:347)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:749)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.widget.TabHost.setCurrentTab(TabHost.java:413)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.widget.TabHost.addTab(TabHost.java:240)
04-18 19:27:28.558: E/AndroidRuntime(1419): at com.cngcnasaud.orar.Carnet.onCreate(Carnet.java:45)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.Activity.performCreate(Activity.java:5231)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
04-18 19:27:28.558: E/AndroidRuntime(1419): ... 11 more
04-18 19:27:28.558: E/AndroidRuntime(1419): Caused by: java.lang.NullPointerException
04-18 19:27:28.558: E/AndroidRuntime(1419): at com.cngcnasaud.orar.NoteAdapter.getCount(NoteAdapter.java:46)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.widget.ListView.setAdapter(ListView.java:480)
04-18 19:27:28.558: E/AndroidRuntime(1419): at com.cngcnasaud.orar.Note.onCreate(Note.java:34)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.Activity.performCreate(Activity.java:5231)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-18 19:27:28.558: E/AndroidRuntime(1419): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
04-18 19:27:28.558: E/AndroidRuntime(1419): ... 21 more
Carnet.java line 45:
tabHost.addTab(NotaSpec);
NoteAdapter.java line 46:
return result.length;
Note.java line 34:
lv.setAdapter(new NoteAdapter(this, prgmNameList, null));
Your String array in null here:
NoteAdapter.java line 46:
return result.length;
because is a class field, you populate in the constructor from a parameter:
public NoteAdapter(Note note, String[] saved, String[] prgmNameList) {
// TODO Auto-generated constructor stub
result = prgmNameList;
that you pass as null here (passed as second parameter, it should be third):
Note.java line 34:
lv.setAdapter(new NoteAdapter(this, prgmNameList, null));
There is no point in passing that as a parameter as it is a public constant (public static final).
First going to say that I know there are a lot of similar posts to this, and I have seen them, however I am new to android development and am not yet familiar enough with it to modify those other answers to fix my exact problem.
I have a fragment that was created by default with a new project that contains a button and text view, and in my MainActivity.java i've made an onClick function for the button. This function throws the NPE. Here's the LogCat:
03-10 19:26:52.620: D/AndroidRuntime(878): Shutting down VM
03-10 19:26:52.620: W/dalvikvm(878): threadid=1: thread exiting with uncaught exception (group=0xb2af2ba8)
03-10 19:26:52.630: E/AndroidRuntime(878): FATAL EXCEPTION: main
03-10 19:26:52.630: E/AndroidRuntime(878): Process: com.example.main, PID: 878
03-10 19:26:52.630: E/AndroidRuntime(878): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.main/com.example.main.MainActivity}: java.lang.NullPointerException
03-10 19:26:52.630: E/AndroidRuntime(878): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
03-10 19:26:52.630: E/AndroidRuntime(878): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
03-10 19:26:52.630: E/AndroidRuntime(878): at android.app.ActivityThread.access$800(ActivityThread.java:135)
03-10 19:26:52.630: E/AndroidRuntime(878): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
03-10 19:26:52.630: E/AndroidRuntime(878): at android.os.Handler.dispatchMessage(Handler.java:102)
03-10 19:26:52.630: E/AndroidRuntime(878): at android.os.Looper.loop(Looper.java:136)
03-10 19:26:52.630: E/AndroidRuntime(878): at android.app.ActivityThread.main(ActivityThread.java:5017)
03-10 19:26:52.630: E/AndroidRuntime(878): at java.lang.reflect.Method.invokeNative(Native Method)
03-10 19:26:52.630: E/AndroidRuntime(878): at java.lang.reflect.Method.invoke(Method.java:515)
03-10 19:26:52.630: E/AndroidRuntime(878): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
03-10 19:26:52.630: E/AndroidRuntime(878): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
03-10 19:26:52.630: E/AndroidRuntime(878): at dalvik.system.NativeStart.main(Native Method)
03-10 19:26:52.630: E/AndroidRuntime(878): Caused by: java.lang.NullPointerException
03-10 19:26:52.630: E/AndroidRuntime(878): at com.example.main.MainActivity.onCreate(MainActivity.java:31)
03-10 19:26:52.630: E/AndroidRuntime(878): at android.app.Activity.performCreate(Activity.java:5231)
03-10 19:26:52.630: E/AndroidRuntime(878): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
03-10 19:26:52.630: E/AndroidRuntime(878): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
03-10 19:26:52.630: E/AndroidRuntime(878): ... 11 more
03-10 19:31:54.292: I/Process(878): Sending signal. PID: 878 SIG: 9
The MainActivity.java:
package com.example.main;
import android.support.v7.app.ActionBarActivity;
...
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
final TextView myText = (TextView) findViewById(R.id.text1);
Button myButton = (Button) findViewById(R.id.button1);
myButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
myText.setText("Yes!");
}
});
}
#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;
}
#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);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}
}
If the TextView and the Button are in the layout's fragment, you need to find their id in the onCreatedView method of the fragment. Then, you should do:
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
final TextView myText = (TextView) rootView.findViewById(R.id.text1);
Button myButton = (Button) rootView.findViewById(R.id.button1);
myButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
myText.setText("Yes!");
}
});
return rootView;
}
}
then myButton is null. so findViewById(R.id.button1) is returning null. You should make sure that is the id you have used for the button your layout (R.layout.fragment_main)
I don't see any fetal mistakes in your OnCreate code but here are some hints to solve the problem
1) Make sure that youractivity is initialized in the Manifest.xml file.
2) Try to run the project after commenting the onClickListener part to make sure that your problem is not in the inflation or in the Layout xml file itself.
3) Try to debug yourOnCreate method and monitor all the different variable values by selecting the variable TO find out the problem
4) Make sure that your button and TextView are in the layout that you are inflating
I hope I could help
The myButton.setOnClickListener(new View.OnClickListener() line gives an exception because its done after you started the fragment, I believe. Put that code in the fragment constructor, and you should be good.
This is my Login.java code
package com.pmss;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
public class Login extends Activity {
Button login, register;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
login = (Button) findViewById(R.id.login);
register = (Button) findViewById(R.id.register);
login.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
//startActivity(new Intent());
}
});
register.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(Login.this, Register.class);
startActivity(new Intent(intent));
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.login, menu);
return true;
}
}
This is my Register.java
package com.pmss;
import android.annotation.SuppressLint;
import android.app.SearchManager;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.SearchView;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
public class Register extends ActionBarActivity {
public final static String EXTRA_MESSAGE = "com.pmss.MESSAGE";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
#SuppressLint("NewApi")
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu items for use in the action bar
/*MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.register, menu);
return super.onCreateOptionsMenu(menu);*/
getMenuInflater().inflate(R.menu.register, menu);
// Get the SearchView and set the searchable configuration
SearchManager searchManager = (SearchManager)getSystemService(Context.SEARCH_SERVICE);
SearchView searchView = (SearchView) menu.findItem(R.id.action_search).getActionView();
searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
// searchView.setIconifiedByDefault(false);
return true;
}
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
// Do something in response to button
Intent intent = new Intent(this, RegisterNextPart.class);
EditText editText = (EditText) findViewById(R.id.nametext);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle presses on the action bar items
switch (item.getItemId()) {
case R.id.action_search:
openSearch();
return true;
case R.id.action_settings:
openSettings();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public void openSearch(){
}
public void openSettings(){
}
}
I wonder is it anything to do with this coding:
register = (Button) findViewById(R.id.register);
register.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(Login.this, Register.class);
startActivity(new Intent(intent));
}
});
When run on my mobile phone and I tap register button which end up force close the application. Anybody help me? really new to ADT
And This is my logcat
11-23 22:09:32.029: W/dalvikvm(15739): VFY: unable to resolve interface method 7433: Landroid/view/MenuItem;.getActionView ()Landroid/view/View;
11-23 22:09:32.169: D/AndroidRuntime(15739): Shutting down VM
11-23 22:09:32.169: W/dalvikvm(15739): threadid=1: thread exiting with uncaught exception (group=0x40018578)
11-23 22:09:32.169: E/AndroidRuntime(15739): FATAL EXCEPTION: main
11-23 22:09:32.169: E/AndroidRuntime(15739): java.lang.NoSuchMethodError: android.view.MenuItem.getActionView
11-23 22:09:32.169: E/AndroidRuntime(15739): at com.pmss.Register.onCreateOptionsMenu(Register.java:36)
11-23 22:09:32.169: E/AndroidRuntime(15739): at android.app.Activity.onCreatePanelMenu(Activity.java:2158)
11-23 22:09:32.169: E/AndroidRuntime(15739): at android.support.v4.app.FragmentActivity.onCreatePanelMenu(FragmentActivity.java:224)
11-23 22:09:32.169: E/AndroidRuntime(15739): at android.support.v7.app.ActionBarActivity.superOnCreatePanelMenu(ActionBarActivity.java:232)
11-23 22:09:32.169: E/AndroidRuntime(15739): at android.support.v7.app.ActionBarActivityDelegateBase$1.run(ActionBarActivityDelegateBase.java:70)
11-23 22:09:32.169: E/AndroidRuntime(15739): at android.os.Handler.handleCallback(Handler.java:587)
11-23 22:09:32.169: E/AndroidRuntime(15739): at android.os.Handler.dispatchMessage(Handler.java:92)
11-23 22:09:32.169: E/AndroidRuntime(15739): at android.os.Looper.loop(Looper.java:130)
11-23 22:09:32.169: E/AndroidRuntime(15739): at android.app.ActivityThread.main(ActivityThread.java:3687)
11-23 22:09:32.169: E/AndroidRuntime(15739): at java.lang.reflect.Method.invokeNative(Native Method)
11-23 22:09:32.169: E/AndroidRuntime(15739): at java.lang.reflect.Method.invoke(Method.java:507)
11-23 22:09:32.169: E/AndroidRuntime(15739): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
11-23 22:09:32.169: E/AndroidRuntime(15739): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
11-23 22:09:32.169: E/AndroidRuntime(15739): at dalvik.system.NativeStart.main(Native Method)
Change your register button setOnClickListener code to
register.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(Login.this, Register.class);
startActivity(intent);
}
});
And Don't Forget to add Activity in your Manifest File
<activity
android:name=".Register"
android:label="#string/app_name">
</activity>
Ther are so many cases why this error is occured.
1) May be you have forgot to add Register activity to your Menifest File.
2) The ID which you are providing for registed is wrong
and so other also, It's very hard to tell without logcat. But this are cases which might occur.
I keep getting nullpointerexception errors when I try to start a second activity from my main activity, my main activity code goes as such:
package com.cep.daredevil;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.Toast;
public class MainActivity extends Activity {
public boolean filled = true;
EditText taskArray[] = new EditText[200];
EditText descArray[] = new EditText[200];
String taskArr[] = new String[200];
String descArr[] = new String[200];
int taskId[] = new int[200];
int descId[] = new int[200];
int n=0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LinearLayout llayout = (LinearLayout)findViewById(R.id.llayout);
Button addfield = new Button(this);
addfield.setText("+");
llayout.addView(addfield);
addfield.setOnClickListener(new Button.OnClickListener()
{
public void onClick(View v)
{
addtask();
}
});
for(int i=0;i<3;i++)
{
addtask();
}
LinearLayout blayout = (LinearLayout)findViewById(R.id.blayout);
Button submit = new Button(this);
submit.setText("Enter Dare");
Button viewdare = new Button(this);
viewdare.setText("View Dares");
blayout.addView(submit);
blayout.addView(viewdare);
submit.setOnClickListener(new Button.OnClickListener()
{
public void onClick(View v)
{
inputdare(null);
}
});
viewdare.setOnClickListener(new Button.OnClickListener()
{
public void onClick(View v)
{
listdare();
}
});
}
#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;
}
public void addtask()
{
LinearLayout llayout = (LinearLayout)findViewById(R.id.llayout);
taskArray[n] = new EditText(this);
taskArray[n].setHint("Task Title");
taskArray[n].setId(n+10000000);
taskArray[n].setPadding(26,30,25,8);
descArray[n] = new EditText(this);
descArray[n].setHint("Task Description");
descArray[n].setId(n+20000000);
llayout.addView(taskArray[n]);
llayout.addView(descArray[n]);
n++;
}
public void inputdare(View v){
EditText daretitle = (EditText)findViewById(R.id.title);
String dare = daretitle.getText().toString();
for (int i=0;i<n;i++)
{
if (taskArr[i] != null)
{
taskArr[i] = taskArray[i].getText().toString();
}
Integer id = taskArray[i].getId();
if (id != null)
{
taskId[i] = id;
}
}
Intent intent = new Intent(this, DisplayDares.class);
Bundle bundle = new Bundle();
bundle.putStringArray("TASKS", taskArr);
bundle.putIntArray("TASKID", taskId);
bundle.putBoolean("INPUT", true);
intent.putExtras(bundle);
startActivity(intent);
}
}
public void listdare()
{
Intent intent = new Intent(this, DisplayDares.class);
Bundle bundle = new Bundle();
bundle.putBoolean("INPUT", false);
intent.putExtras(bundle);
startActivity(intent);
}
}
the function that seems to be causing the problem is in my second activity, over here:
package com.cep.daredevil;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.LinearLayout;
import android.widget.TextView;
public class DisplayDares extends Activity {
public final static String PREFS = "Preferences";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.display_dare);
setupActionBar();
Bundle bundle = getIntent().getExtras();
Boolean input = bundle.getBoolean("INPUT");
if (input == false){}
else
{
int[] taskId = bundle.getIntArray("TASKID");
final String[] taskArray = bundle.getStringArray("TASKS");
LinearLayout layout = (LinearLayout)findViewById(R.id.layout);
TextView test = (TextView)findViewById(taskId[0]);
test.setText(taskArray[1]);
layout.addView(test);
}
}
}
the error I get is this:
03-08 13:32:18.053: E/AndroidRuntime(6873): FATAL EXCEPTION: main
03-08 13:32:18.053: E/AndroidRuntime(6873): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.cep.daredevil/com.cep.daredevil.DisplayDares}: java.lang.NullPointerException
03-08 13:32:18.053: E/AndroidRuntime(6873): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
03-08 13:32:18.053: E/AndroidRuntime(6873): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
03-08 13:32:18.053: E/AndroidRuntime(6873): at android.app.ActivityThread.access$600(ActivityThread.java:141)
03-08 13:32:18.053: E/AndroidRuntime(6873): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
03-08 13:32:18.053: E/AndroidRuntime(6873): at android.os.Handler.dispatchMessage(Handler.java:99)
03-08 13:32:18.053: E/AndroidRuntime(6873): at android.os.Looper.loop(Looper.java:137)
03-08 13:32:18.053: E/AndroidRuntime(6873): at android.app.ActivityThread.main(ActivityThread.java:5041)
03-08 13:32:18.053: E/AndroidRuntime(6873): at java.lang.reflect.Method.invokeNative(Native Method)
03-08 13:32:18.053: E/AndroidRuntime(6873): at java.lang.reflect.Method.invoke(Method.java:511)
03-08 13:32:18.053: E/AndroidRuntime(6873): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
03-08 13:32:18.053: E/AndroidRuntime(6873): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
03-08 13:32:18.053: E/AndroidRuntime(6873): at dalvik.system.NativeStart.main(Native Method)
03-08 13:32:18.053: E/AndroidRuntime(6873): Caused by: java.lang.NullPointerException
03-08 13:32:18.053: E/AndroidRuntime(6873): at com.cep.daredevil.DisplayDares.onCreate(DisplayDares.java:32)
03-08 13:32:18.053: E/AndroidRuntime(6873): at android.app.Activity.performCreate(Activity.java:5104)
03-08 13:32:18.053: E/AndroidRuntime(6873): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
03-08 13:32:18.053: E/AndroidRuntime(6873): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
After pasing your code it seems line 34 is:
layout.addView(test);
So this line generates a nullpointer exception
Check if the id of your layout is the same.
Tip:
Further in your error stacktrace you can see what causes the error:
03-08 13:32:18.053: E/AndroidRuntime(6873): Caused by: java.lang.NullPointerException
03-08 13:32:18.053: E/AndroidRuntime(6873): at com.cep.daredevil.DisplayDares.onCreate(DisplayDares.java:34)
DisplayDares.java:34
Means line 34 in your DisplayDares.java file.
You will see it is the following line:
layout.addView(test);
Now test cannot be NULL because it wouldn't have thrown that error. So layout must be.