CODEWITHSUNDEEP
javaandroideclipse
thetigerhay
thetigerhay

Reputation: 11

NullPointerException with ListView

I am playing around with using a ListView with an Navigation Drawer. Eclipse does not give me any errors but when i start the code in the emulator it says: "Unfortunately, DrunKingz has stopped."

MainActivity.java : 

package de.pascalborker.drunkingz;

import android.app.ListActivity;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.widget.DrawerLayout;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends ListActivity implements OnClickListener{
	

	private DrawerLayout DrawerLayout;
	private ActionBarDrawerToggle ActionBarDrawerToggle;
	
	public ListView drawerlist;
	public String[] listentext = {"DrunKingz","Songs","Kontakt"};

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		//setContentView(R.layout.activity_main);

		DrawerLayout = (DrawerLayout) findViewById(R.id.dlDrawerLayout);
		ActionBarDrawerToggle = new ActionBarDrawerToggle(this, DrawerLayout, R.drawable.icon_drawer, R.string.open, R.string.close);
		DrawerLayout.setDrawerListener(ActionBarDrawerToggle);

		getActionBar().setDisplayHomeAsUpEnabled(true);
		getActionBar().setHomeButtonEnabled(true);
		
		// ListView
		// ------
		// ------
		
		drawerlist = (ListView) findViewById(R.id.drawerliste);
		ArrayAdapter<String> drawerlistadapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, listentext);
		drawerlist.setAdapter(drawerlistadapter);
		drawerlist.setOnItemClickListener(new OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView<?> parent, View view,
					int position, long id) {
				
				switch (drawerlist.getPositionForView(view)) {
				case 0: {
					Toast.makeText(getApplicationContext(), "DrunKingz", Toast.LENGTH_SHORT).show();
					break;
						}
				
				case 1: {
					Toast.makeText(getApplicationContext(), "Songs", Toast.LENGTH_SHORT).show();
					break;
						}
				
				case 2: {
					Toast.makeText(getApplicationContext(), "Kontakt", Toast.LENGTH_SHORT).show();
					break;
						}
					

				}
				
			}
		});
		
	}

	@Override
	protected void onPostCreate(Bundle savedInstanceState) {
		super.onPostCreate(savedInstanceState);

		ActionBarDrawerToggle.syncState();
	}

	@Override
	public void onConfigurationChanged(Configuration newConfig) {
		super.onConfigurationChanged(newConfig);

		ActionBarDrawerToggle.onConfigurationChanged(newConfig);
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {

		if (ActionBarDrawerToggle.onOptionsItemSelected(item)) {
			return true;
		}

		return super.onOptionsItemSelected(item);
	}

	@Override
	public void onClick(View v) {
		Toast.makeText(getApplicationContext(), "Test", Toast.LENGTH_SHORT).show();
	}

}

activity_main.xml :

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/dlDrawerLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <!-- Content -->
    <RelativeLayout
            android:id="@+id/rlContent"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

        <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:text="@string/hauptansicht"
                android:gravity="center"/>


    </RelativeLayout>
    <!-- Menu -->
    <RelativeLayout
            android:id="@+id/rlDrawer"
            android:layout_width="240dp"
            android:layout_height="match_parent"
            android:layout_gravity="start"
            android:background="#111">
        
        <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:text="@string/menuansicht"
                android:gravity="center"/>
        
        <ListView 
            android:id="@+id/drawerliste"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            
            
            ></ListView>

    </RelativeLayout>
</android.support.v4.widget.DrawerLayout>

LogCat :

09-20 21:37:02.920: E/AndroidRuntime(827): FATAL EXCEPTION: main
09-20 21:37:02.920: E/AndroidRuntime(827): java.lang.RuntimeException: Unable to start activity ComponentInfo{de.pascalborker.drunkingz/de.pascalborker.drunkingz.MainActivity}: java.lang.NullPointerException
09-20 21:37:02.920: E/AndroidRuntime(827): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at android.app.ActivityThread.access$600(ActivityThread.java:123)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at android.os.Handler.dispatchMessage(Handler.java:99)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at android.os.Looper.loop(Looper.java:137)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at android.app.ActivityThread.main(ActivityThread.java:4424)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at java.lang.reflect.Method.invokeNative(Native Method)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at java.lang.reflect.Method.invoke(Method.java:511)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at dalvik.system.NativeStart.main(Native Method)
09-20 21:37:02.920: E/AndroidRuntime(827): Caused by: java.lang.NullPointerException
09-20 21:37:02.920: E/AndroidRuntime(827): 	at de.pascalborker.drunkingz.MainActivity.onCreate(MainActivity.java:33)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at android.app.Activity.performCreate(Activity.java:4465)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
09-20 21:37:02.920: E/AndroidRuntime(827): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
09-20 21:37:02.920: E/AndroidRuntime(827): 	... 11 more
09-20 21:39:05.640: A/BatteryStatsImpl(77): problem reading network stats
09-20 21:39:05.640: A/BatteryStatsImpl(77): java.lang.IllegalStateException: problem parsing idx 1
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.internal.net.NetworkStatsFactory.readNetworkStatsDetail(NetworkStatsFactory.java:300)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.internal.net.NetworkStatsFactory.readNetworkStatsDetail(NetworkStatsFactory.java:250)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.internal.os.BatteryStatsImpl.getNetworkStatsDetailGroupedByUid(BatteryStatsImpl.java:5734)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.internal.os.BatteryStatsImpl.access$100(BatteryStatsImpl.java:76)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.internal.os.BatteryStatsImpl$Uid.computeCurrentTcpBytesReceived(BatteryStatsImpl.java:2457)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.internal.os.BatteryStatsImpl$Uid.getTcpBytesReceived(BatteryStatsImpl.java:2446)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.internal.os.BatteryStatsImpl.writeSummaryToParcel(BatteryStatsImpl.java:5437)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.internal.os.BatteryStatsImpl.writeLocked(BatteryStatsImpl.java:4836)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.internal.os.BatteryStatsImpl.writeAsyncLocked(BatteryStatsImpl.java:4818)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.server.am.ActivityManagerService.updateCpuStatsNow(ActivityManagerService.java:1652)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.server.am.ActivityManagerService$3.run(ActivityManagerService.java:1534)
09-20 21:39:05.640: A/BatteryStatsImpl(77): Caused by: java.io.FileNotFoundException: /proc/net/xt_qtaguid/stats: open failed: ENOENT (No such file or directory)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at libcore.io.IoBridge.open(IoBridge.java:406)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at java.io.FileInputStream.<init>(FileInputStream.java:78)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at com.android.internal.net.NetworkStatsFactory.readNetworkStatsDetail(NetworkStatsFactory.java:269)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	... 10 more
09-20 21:39:05.640: A/BatteryStatsImpl(77): Caused by: libcore.io.ErrnoException: open failed: ENOENT (No such file or directory)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at libcore.io.Posix.open(Native Method)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at libcore.io.BlockGuardOs.open(BlockGuardOs.java:110)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	at libcore.io.IoBridge.open(IoBridge.java:390)
09-20 21:39:05.640: A/BatteryStatsImpl(77): 	... 12 more
09-20 21:48:39.280: E/AndroidRuntime(868): FATAL EXCEPTION: main
09-20 21:48:39.280: E/AndroidRuntime(868): java.lang.RuntimeException: Unable to start activity ComponentInfo{de.pascalborker.drunkingz/de.pascalborker.drunkingz.MainActivity}: java.lang.NullPointerException
09-20 21:48:39.280: E/AndroidRuntime(868): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at android.app.ActivityThread.access$600(ActivityThread.java:123)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at android.os.Handler.dispatchMessage(Handler.java:99)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at android.os.Looper.loop(Looper.java:137)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at android.app.ActivityThread.main(ActivityThread.java:4424)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at java.lang.reflect.Method.invokeNative(Native Method)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at java.lang.reflect.Method.invoke(Method.java:511)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at dalvik.system.NativeStart.main(Native Method)
09-20 21:48:39.280: E/AndroidRuntime(868): Caused by: java.lang.NullPointerException
09-20 21:48:39.280: E/AndroidRuntime(868): 	at de.pascalborker.drunkingz.MainActivity.onCreate(MainActivity.java:33)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at android.app.Activity.performCreate(Activity.java:4465)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
09-20 21:48:39.280: E/AndroidRuntime(868): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
09-20 21:48:39.280: E/AndroidRuntime(868): 	... 11 more

Anyone know what might be causing this?

Upvotes: 0

Views: 187

Answers (1)

El Abogato
El Abogato

Reputation: 123

In your onCreate()

//setContentView(R.layout.activity_main);

DrawerLayout = (DrawerLayout) findViewById(R.id.dlDrawerLayout);

if you did not set the content View with that layout, then findViewById will return null, and

DrawerLayout.setDrawerListener(ActionBarDrawerToggle);

that will throw the NullPointerException.

uncomment that line

Upvotes: 1

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