ANDROID [後退按鈕導致崩潰]

Question

所以我有3個活動（LauncherActivity> MenuAvtivity> SelectionActivity） 當我按下後退按鈕從SelectionActivity返回到MenuActivity時，我的應用程序崩潰。

Code: Intent intent = new Intent(MenuActivity.this,SelectionActivity.class); 
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
    startActivity(intent); 

錯誤代碼：

12-21 20:37:52.179: E/AndroidRuntime(14823): FATAL EXCEPTION: main 
12-21 20:37:52.179: E/AndroidRuntime(14823): Process: com.example.myapp, PID: 14823 
12-21 20:37:52.179: E/AndroidRuntime(14823): java.lang.IllegalThreadStateException: Thread already started 
12-21 20:37:52.179: E/AndroidRuntime(14823): at java.lang.Thread.checkNotStarted(Thread.java:871) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at java.lang.Thread.start(Thread.java:1025) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at com.example.myapp.MenuView$1.surfaceCreated(MenuView.java:51) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.SurfaceView.updateWindow(SurfaceView.java:662) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.SurfaceView.onWindowVisibilityChanged(SurfaceView.java:256) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.View.dispatchWindowVisibilityChanged(View.java:8096) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1110) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1110) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1110) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1448) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1192) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6231) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:788) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.Choreographer.doCallbacks(Choreographer.java:591) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.Choreographer.doFrame(Choreographer.java:560) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:774) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.os.Handler.handleCallback(Handler.java:808) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.os.Handler.dispatchMessage(Handler.java:103) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.os.Looper.loop(Looper.java:193) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at android.app.ActivityThread.main(ActivityThread.java:5292) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at java.lang.reflect.Method.invokeNative(Native Method) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at java.lang.reflect.Method.invoke(Method.java:515) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640) 
12-21 20:37:52.179: E/AndroidRuntime(14823): at dalvik.system.NativeStart.main(Native Method) 

的LauncherActivity使用SurfaceView和MenuActivity用在Canvas線程繪製SurfaceView。

Thread類：

@Override 
public void run() { 
    while (running) { 
     Canvas c = null; 
     try { 
      c = menuView.getHolder().lockCanvas(); 
      synchronized (menuView.getHolder()) { 
       menuView.doDraw(c); 
      } 
     } finally { 
      if (c != null) { 
       menuView.getHolder().unlockCanvasAndPost(c); 
      } 
     } 
    } 
} 

Answer 1

.IllegalThreadStateException：螺紋在surfaceCreated你打電話thread.start已經開始

左右。不過那個線程以前已經啓動了。所以要麼不要重新啓動它，要麼創建一個新的線程。我的猜測是第一個是正確的答案，但沒有代碼我無法確定。