Приложение силы close thenewboston android tutorial

Question

Я уже проходил учебник по андроиде от thenewboston и застрял в 41-м учебнике. Мое приложение закрывает силу, как только я открываю активность камеры.

Camera.java

package com.thenewboston.akshit; 

import java.io.IOException; 

import android.app.Activity; 
import android.content.Intent; 
import android.graphics.Bitmap; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Button; 
import android.widget.ImageButton; 
import android.widget.ImageView; 

public class Camera extends Activity implements View.OnClickListener { 

ImageButton ib; 
Button b; 
ImageView iv; 
Intent i; 
final static int cameraData=0; 
Bitmap bmp; 


@Override 
protected void onCreate(Bundle savedInstanceState) { 
    // TODO Auto-generated method stub 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.photo); 
    initialize(); 

} 
private void initialize() { 
    iv = (ImageView) findViewById(R.id.ivReturnedPic); 
    b = (Button) findViewById(R.id.bSetWall); 
    iv = (ImageView) findViewById(R.id.ivReturnedPic); 
    b.setOnClickListener(this); 
    ib.setOnClickListener(this); 
} 

@Override 
public void onClick(View v) { 
    // TODO Auto-generated method stub 
    switch (v.getId()){ 
    case R.id.bSetWall: 
     try{ 
     getApplicationContext().setWallpaper(bmp);} 
     catch (IOException e) { e.printStackTrace(); }  
     break; 

    case R.id.ibTakePic: 
     i = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE); 
    startActivityForResult(i,cameraData); 

     break; 

    } 

} 
@Override 
protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
    // TODO Auto-generated method stub 
    super.onActivityResult(requestCode, resultCode, data); 
    if(resultCode==RESULT_OK){ 
     Bundle extras =data.getExtras(); 
     bmp = (Bitmap) extras.get("data"); 
     iv.setImageBitmap(bmp); 

    } 
} 

}

Menu.java

package com.thenewboston.akshit; 

import android.app.ListActivity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 

public class Menu extends ListActivity { 
String classes[] = {"StartingPoint", "TextPlay", "Email", "Camera"}; 


@Override 
protected void onCreate(Bundle savedInstanceState) { 
    // TODO Auto-generated method stub 
    super.onCreate(savedInstanceState); 
    setListAdapter(new ArrayAdapter<String>(Menu.this, android.R.layout.simple_list_item_1, classes)); 

} 


@Override 
protected void onListItemClick(ListView l, View v, int position, long id) { 
    // TODO Auto-generated method stub 
    String cheese = classes[position]; 
    super.onListItemClick(l, v, position, id); 
    try{ 
    Class ourClass = Class.forName("com.thenewboston.akshit." + cheese); 
    Intent ourIntent = new Intent(Menu.this, ourClass); 
    startActivity(ourIntent); 
    }catch(ClassNotFoundException e){ 
     e.printStackTrace(); 
    } 


} 

}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.thenewboston.akshit" 
android:versionCode="1" 
android:versionName="1.0" > 

<uses-sdk 
    android:minSdkVersion="8" 
    android:targetSdkVersion="18" /> 
<uses-permission android:name="android.permission.SET_WALLPAPER"/> 

<application 
    android:allowBackup="true" 
    android:icon="@drawable/ic_launcher" 
    android:label="@string/app_name" 
    android:theme="@style/AppTheme" > 
    <activity 
     android:name="com.thenewboston.akshit.Splash" 
     android:label="Splash" > 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
    <activity 
     android:name="com.thenewboston.akshit.StartingPoint" 
     android:label="Starting Point" > 
     <intent-filter> 
      <action android:name="com.thenewboston.akshit.STARTINGPOINT" /> 

      <category android:name="android.intent.category.DEFAULT" /> 
     </intent-filter> 
    </activity> 
    <activity 
     android:name="com.thenewboston.akshit.Menu" 
     android:label="Starting Point" > 
     <intent-filter> 
      <action android:name="com.thenewboston.akshit.MENU" /> 

      <category android:name="android.intent.category.DEFAULT" /> 
     </intent-filter> 
    </activity> 
    <activity 
     android:name="com.thenewboston.akshit.TextPlay" 
     android:label="Starting Point" > 
    </activity> 
    <activity 
     android:name="com.thenewboston.akshit.Email" 
     android:label="Starting Point" > 
    </activity> 
    <activity 
     android:name="com.thenewboston.akshit.Camera" 
     android:label="Starting Point" > 
    </activity> 
</application> 

журнал

06-28 03:23:03.080: D/dalvikvm(871): Not late-enabling CheckJNI (already on) 
06-28 03:23:06.280: D/gralloc_goldfish(871): Emulator without GPU emulation detected. 
06-28 03:23:09.520: D/dalvikvm(871): GC_FOR_ALLOC freed 55K, 5% free 3032K/3172K, paused 124ms, total 130ms 
06-28 03:23:09.520: I/dalvikvm-heap(871): Grow heap (frag case) to 3.646MB for 635812-byte allocation 
06-28 03:23:09.590: D/dalvikvm(871): GC_FOR_ALLOC freed 6K, 4% free 3646K/3796K, paused 63ms, total 63ms 
06-28 03:23:10.210: I/Choreographer(871): Skipped 72 frames! The application may be doing too much work on its main thread. 
06-28 03:23:15.810: D/AndroidRuntime(871): Shutting down VM 
06-28 03:23:15.810: W/dalvikvm(871): threadid=1: thread exiting with uncaught exception (group=0xb3a36b90) 
06-28 03:23:15.850: E/AndroidRuntime(871): FATAL EXCEPTION: main 
06-28 03:23:15.850: E/AndroidRuntime(871): Process: com.thenewboston.akshit, PID: 871 
06-28 03:23:15.850: E/AndroidRuntime(871): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.thenewboston.akshit/com.thenewboston.akshit.Camera}: java.lang.NullPointerException 
06-28 03:23:15.850: E/AndroidRuntime(871): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2176) 
06-28 03:23:15.850: E/AndroidRuntime(871): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226) 
06-28 03:23:15.850: E/AndroidRuntime(871): at android.app.ActivityThread.access$700(ActivityThread.java:135) 
06-28 03:23:15.850: E/AndroidRuntime(871): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397) 
06-28 03:23:15.850: E/AndroidRuntime(871): at android.os.Handler.dispatchMessage(Handler.java:102) 
06-28 03:23:15.850: E/AndroidRuntime(871): at android.os.Looper.loop(Looper.java:137) 
06-28 03:23:15.850: E/AndroidRuntime(871): at android.app.ActivityThread.main(ActivityThread.java:4998) 
06-28 03:23:15.850: E/AndroidRuntime(871): at java.lang.reflect.Method.invokeNative(Native Method) 
06-28 03:23:15.850: E/AndroidRuntime(871): at java.lang.reflect.Method.invoke(Method.java:515) 
06-28 03:23:15.850: E/AndroidRuntime(871): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777) 
06-28 03:23:15.850: E/AndroidRuntime(871): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593) 
06-28 03:23:15.850: E/AndroidRuntime(871): at dalvik.system.NativeStart.main(Native Method) 
06-28 03:23:15.850: E/AndroidRuntime(871): Caused by: java.lang.NullPointerException 
06-28 03:23:15.850: E/AndroidRuntime(871): at com.thenewboston.akshit.Camera.initialize(Camera.java:37) 
06-28 03:23:15.850: E/AndroidRuntime(871): at com.thenewboston.akshit.Camera.onCreate(Camera.java:29) 
06-28 03:23:15.850: E/AndroidRuntime(871): at android.app.Activity.performCreate(Activity.java:5243) 
06-28 03:23:15.850: E/AndroidRuntime(871): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
06-28 03:23:15.850: E/AndroidRuntime(871): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2140) 
06-28 03:23:15.850: E/AndroidRuntime(871): ... 11 more 
06-28 03:23:19.850: I/Process(871): Sending signal. PID: 871 SIG: 9 

Answer 1

Вы должны установить ссылку на И.Б. на функцию инициализировать перед установкой щелчка слушателя к нему.

ib = (ImageButton) findViewById(R.id.ib) //Or the name that the ImageButton has 
ib.setOnClickListener(this);