找不到處理意圖的活動{act = android.service.wallpaper.CHANGE_LIVE_WALLPAPER（has extras）}

Question

我正在爲android創建動態壁紙應用程序。我已經寫了一些代碼，但我得到所致以下錯誤：android.content.ActivityNotFoundException：無活動處理意向{行動= android.service.wallpaper.CHANGE_LIVE_WALLPAPER（有演員）}

請幫助

MyPoint.java

public class MyPoint { 
public String text; 
public float x; 
public float y; 

public MyPoint(String text, float x, float y) { 
    this.text = text; 
    this.x = x; 
    this.y = y; 
} 

} 

MyPreferencesActivity.java

public class MyPreferencesActivity extends PreferenceActivity { 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    addPreferencesFromResource(R.xml.prefs); 

    Preference circlePreference = getPreferenceScreen().findPreference(
      "numberOfCircles"); 
    circlePreference.setOnPreferenceChangeListener(numberCheckListener); 
} 

Preference.OnPreferenceChangeListener numberCheckListener = new OnPreferenceChangeListener() { 

    @Override 
    public boolean onPreferenceChange(Preference preference, Object newValue) { 
     if (newValue != null && newValue.toString().length() > 0 
       && newValue.toString().matches("\\d*")) { 
      return true; 
     } 
     Toast.makeText(MyPreferencesActivity.this, "Invalid Input", 
       Toast.LENGTH_SHORT).show(); 
     return false; 
    } 
}; 
} 

MyWallpaperService.java

public class MyWallpaperService extends WallpaperService { 

@Override 
public Engine onCreateEngine() { 
    return new MyWallpaperEngine(); 
} 

private class MyWallpaperEngine extends Engine { 
    private final Handler handler = new Handler(); 
    private final Runnable drawRunner = new Runnable() { 
     @Override 
     public void run() { 
      draw(); 
     } 

    }; 
    private List<MyPoint> circles; 
    private Paint paint = new Paint(); 
    private int width; 
    int height; 
    private boolean visible = true; 
    private int maxNumber; 
    private boolean touchEnabled; 

    public MyWallpaperEngine() { 
     SharedPreferences prefs = PreferenceManager 
       .getDefaultSharedPreferences(MyWallpaperService.this); 
     maxNumber = Integer 
       .valueOf(prefs.getString("numberOfCircles", "4")); 
     touchEnabled = prefs.getBoolean("touch", false); 
     circles = new ArrayList<MyPoint>(); 
     paint.setAntiAlias(true); 
     paint.setColor(Color.WHITE); 
     paint.setStyle(Paint.Style.STROKE); 
     paint.setStrokeJoin(Paint.Join.ROUND); 
     paint.setStrokeWidth(10f); 
     handler.post(drawRunner); 
    } 

    @Override 
    public void onVisibilityChanged(boolean visible) { 
     this.visible = visible; 
     if (visible) { 
      handler.post(drawRunner); 
     } else { 
      handler.removeCallbacks(drawRunner); 
     } 
    } 

    @Override 
    public void onSurfaceDestroyed(SurfaceHolder holder) { 
     super.onSurfaceDestroyed(holder); 
     this.visible = false; 
     handler.removeCallbacks(drawRunner); 
    } 

    @Override 
    public void onSurfaceChanged(SurfaceHolder holder, int format, 
      int width, int height) { 
     this.width = width; 
     this.height = height; 
     super.onSurfaceChanged(holder, format, width, height); 
    } 

    @Override 
    public void onTouchEvent(MotionEvent event) { 
     if (touchEnabled) { 

      float x = event.getX(); 
      float y = event.getY(); 
      SurfaceHolder holder = getSurfaceHolder(); 
      Canvas canvas = null; 
      try { 
       canvas = holder.lockCanvas(); 
       if (canvas != null) { 
        canvas.drawColor(Color.BLACK); 
        circles.clear(); 
        circles.add(new MyPoint(
          String.valueOf(circles.size() + 1), x, y)); 
        drawCircles(canvas, circles); 

       } 
      } finally { 
       if (canvas != null) 
        holder.unlockCanvasAndPost(canvas); 
      } 
      super.onTouchEvent(event); 
     } 
    } 

    private void draw() { 
     SurfaceHolder holder = getSurfaceHolder(); 
     Canvas canvas = null; 
     try { 
      canvas = holder.lockCanvas(); 
      if (canvas != null) { 
       if (circles.size() >= maxNumber) { 
        circles.clear(); 
       } 
       int x = (int) (width * Math.random()); 
       int y = (int) (height * Math.random()); 
       circles.add(new MyPoint(String.valueOf(circles.size() + 1), 
         x, y)); 
       drawCircles(canvas, circles); 
      } 
     } finally { 
      if (canvas != null) 
       holder.unlockCanvasAndPost(canvas); 
     } 
     handler.removeCallbacks(drawRunner); 
     if (visible) { 
      handler.postDelayed(drawRunner, 5000); 
     } 
    } 

    // Surface view requires that all elements are drawn completely 
    private void drawCircles(Canvas canvas, List<MyPoint> circles) { 
     canvas.drawColor(Color.BLACK); 
     for (MyPoint point : circles) { 
      canvas.drawCircle(point.x, point.y, 20.0f, paint); 
     } 
    } 
} 
} 

SetWallpaperActivity.java

public class SetWallpaperActivity extends Activity { 

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

public void clickMe(View view) { 
    Intent intent = new Intent(
      WallpaperManager.ACTION_CHANGE_LIVE_WALLPAPER); 
    intent.putExtra(WallpaperManager.EXTRA_LIVE_WALLPAPER_COMPONENT, 
      new ComponentName(this, MyWallpaperService.class)); 
    startActivity(intent); 
} 

} 

activity_set_wallpaper.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
tools:context=".SetWallpaperActivity" > 

<Button 
    android:layout_height="wrap_content" 
    android:layout_width="fill_parent" 
    android:onClick="clickMe" 
    android:text="Click Me!" /> 

</RelativeLayout> 

mywallpaper.xml

<?xml version="1.0" encoding="utf-8"?> 
<wallpaper xmlns:android="http://schemas.android.com/apk/res/android" 
android:description="@string/wallpaper_description" 
android:settingsActivity="de.vogella.android.wallpaper.MyPreferencesActivity" 
android:thumbnail="@drawable/icon" /> 

的prefs.xml

<?xml version="1.0" encoding="utf-8"?> 
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" > 

<CheckBoxPreference 
    android:key="touch" 
    android:title="Enable Touch" > 
</CheckBoxPreference> 

<EditTextPreference 
    android:key="numberOfCircles" 
    android:title="Number of Circles" > 
</EditTextPreference> 

</PreferenceScreen> 

LOG CAT

02-18 21:08:07.630: E/AndroidRuntime(9406): FATAL EXCEPTION: main 
02-18 21:08:07.630: E/AndroidRuntime(9406): java.lang.IllegalStateException: Could not execute method of the activity 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.view.View$1.onClick(View.java:3095) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.view.View.performClick(View.java:3567) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.view.View$PerformClick.run(View.java:14224) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.os.Handler.handleCallback(Handler.java:605) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.os.Handler.dispatchMessage(Handler.java:92) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.os.Looper.loop(Looper.java:137) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.app.ActivityThread.main(ActivityThread.java:4517) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at java.lang.reflect.Method.invokeNative(Native Method) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at java.lang.reflect.Method.invoke(Method.java:511) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at dalvik.system.NativeStart.main(Native Method) 
02-18 21:08:07.630: E/AndroidRuntime(9406): Caused by: java.lang.reflect.InvocationTargetException 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at java.lang.reflect.Method.invokeNative(Native Method) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at java.lang.reflect.Method.invoke(Method.java:511) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.view.View$1.onClick(View.java:3090) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  ... 11 more 
02-18 21:08:07.630: E/AndroidRuntime(9406): Caused by: android.content.ActivityNotFoundException: No Activity found to handle Intent { act=android.service.wallpaper.CHANGE_LIVE_WALLPAPER (has extras) } 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1536) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1388) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.app.Activity.startActivityForResult(Activity.java:3195) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at android.app.Activity.startActivity(Activity.java:3302) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  at de.vogella.android.wallpaper.SetWallpaperActivity.clickMe(SetWallpaperActivity.java:23) 
02-18 21:08:07.630: E/AndroidRuntime(9406):  ... 14 more 

Answer 1

我不知道什麼樣的目標，你正在構建但the documentation說，在API級別16中添加了，因此如果您在較舊的設備上使用此代碼，則會引發此錯誤。 This answer顯示如何檢查正確的API級別。

除了檢查API級別之外，還可以將該意圖包裝在try/catch中。雖然這是一般的不好的做法，但我認爲這可能是有益的，因爲有些人偶爾會在API級別超過16時報告這種錯誤（儘管這很少見，並且可能與用戶不使用庫存android ROM ）。