SurfaceView中帶有SimpleOnGestureListener的Android手勢檢測器

Question

public class GameActivity extends Activity { 
    private static final String TAG = "GameActivity"; 

    . . . 

    @Override 
    public boolean onTouchEvent(MotionEvent event) { 
     Log.d(TAG, "+ onTouchEvent(event:" + event + ")"); 
     Log.d(TAG, "- onTouchEvent()"); 
     return super.onTouchEvent(event); 
    } 

    . . . 
} 


public class GameView extends SurfaceView implements SurfaceHolder.Callback { 
    private static final String TAG = "GameView"; 

    . . . 

    @Override 
    public boolean onTouchEvent(MotionEvent event) { 
     Log.d(TAG, "+ onTouchEvent(event:" + event + ")"); 
     gestureDetector.onTouchEvent(event); 
     Log.d(TAG, "- onTouchEvent()"); 
     return super.onTouchEvent(event); 
    } 

    private SimpleOnGestureListener gestureListener = new SimpleOnGestureListener() { 
     private static final String TAG = "GestureListener"; 

     @Override 
     public boolean onSingleTapConfirmed(MotionEvent event) { 
      Log.d(TAG, "+ onSingleTapConfirmed(event:" + event + ")"); 
      singleTapDetected = true; 
      Log.d(TAG, "- onSingleTapConfirmed()"); 
      return true; 
     } 

     @Override 
     public boolean onDoubleTap(MotionEvent event) { 
      Log.d(TAG, "+ onDoubleTap(event:" + event + ")"); 
      doubleTapDetected = true; 
      Log.d(TAG, "- onDoubleTap()"); 
      return true; 
     } 
    }; 

    private GestureDetector gestureDetector = new GestureDetector(getContext(), gestureListener); 

    . . . 
} 

我在AVD上運行它，在SurfaceView（GameView）上單擊一下。
據logcat的日誌：

03-11 14:19:51.171: D/GameView(4839): + onTouchEvent(event:MotionEvent { action=ACTION_DOWN, id[0]=0, x[0]=1071.0, y[0]=437.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=27223172, downTime=27223172, deviceId=0, source=0x1002 }) 
03-11 14:19:51.171: D/GameView(4839): - onTouchEvent() 
03-11 14:19:51.171: D/GameActivity(4839): + onTouchEvent(event:MotionEvent { action=ACTION_DOWN, id[0]=0, x[0]=1071.0, y[0]=437.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=27223172, downTime=27223172, deviceId=0, source=0x1002 }) 
03-11 14:19:51.171: D/GameActivity(4839): - onTouchEvent() 
03-11 14:19:51.299: D/GameActivity(4839): + onTouchEvent(event:MotionEvent { action=ACTION_UP, id[0]=0, x[0]=1071.0, y[0]=437.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=27223303, downTime=27223172, deviceId=0, source=0x1002 }) 
03-11 14:19:51.299: D/GameActivity(4839): - onTouchEvent() 

有幾個問題：

1. 爲什麼SimpleOnGestureListener不叫？ （即使onTouchEvent()被稱爲和presummably行gestureDetector.onTouchEvent(event);被處決）

2. 爲什麼GameActivity的onTouchEvent()得到ACTION_DOWN和ACTION_UP，但GameView的onTouchEvent()只得到ACTION_DOWN？

有些事情我已經試過

• 我在GameActivity類相同的代碼實現的GestureDetector如上圖所示，它的工作如預期，稱onSingleTapConfirmed()

• 在GameView，而不是私人成員SimpleOnGestureListener，創建了一個私人class GestureListener extends SimpleOnGestureListener並用它來構建GestureDetector。我看到了與描述相同的行爲，沒有給監聽者打電話。

Answer 1

我將代碼調試到Android源代碼GestureDetector類中。這解釋了爲什麼SimpleOnGestureListener不叫：

• 的ACTION_DOWN被接收併產生內部TAP消息給GestureDetector消息處理程序。
• 的處理程序將調用監聽onSingleTapConfirmed()只有當事件不仍下降（!mStillDown）
• 事件仍然下跌，因爲從來沒有收到ACTION_UP事件。

所以你看，這兩個問題是相關的，當我發現爲什麼ACTION_UP沒有發出我將解決問題！

編輯

這樣就完成了答案，現在它正在工作。

• 在GameView至super.onTouchEvent()調用返回false，因爲super類SurfaceView是查看，並返回false。這就是爲什麼ACTION_UP永遠不會被調用的原因
• GameActivity中對super.onTouchEvent()的調用返回true，這就是在GameActivity上發出ACTION_UP的原因。

注：如果我設置GameView.setclickable(true)然後super.onTouchEvent()回報true。 這也是一個可接受的解決方案

現在我GameView代碼：

@Override 
public boolean onTouchEvent(MotionEvent event) { 
    Log.d(TAG, "+ onTouchEvent(event:" + event + ")"); 
    gestureDetector.onTouchEvent(event); 
    Log.d(TAG, "- onTouchEvent()"); 
    return true; 
} 

目前的logcat日誌：

03-11 16:32:06.629: D/GameView(5316): + onTouchEvent(event:MotionEvent { action=ACTION_DOWN, id[0]=0, x[0]=977.0, y[0]=414.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=35158623, downTime=35158623, deviceId=0, source=0x1002 }) 
03-11 16:32:06.629: D/GameView(5316): - onTouchEvent() 
03-11 16:32:06.641: D/GameView(5316): + onTouchEvent(event:MotionEvent { action=ACTION_MOVE, id[0]=0, x[0]=978.0, y[0]=414.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=35158623, downTime=35158623, deviceId=0, source=0x1002 }) 
03-11 16:32:06.641: D/GameView(5316): - onTouchEvent() 
03-11 16:32:06.772: D/GameView(5316): + onTouchEvent(event:MotionEvent { action=ACTION_UP, id[0]=0, x[0]=978.0, y[0]=414.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=35158772, downTime=35158623, deviceId=0, source=0x1002 }) 
03-11 16:32:06.772: D/GameView(5316): - onTouchEvent() 
03-11 16:32:06.931: D/GestureListener(5316): + onSingleTapConfirmed(event:MotionEvent { action=ACTION_DOWN, id[0]=0, x[0]=977.0, y[0]=414.0, toolType[0]=TOOL_TYPE_FINGER, buttonState=0, metaState=0, flags=0x0, edgeFlags=0x0, pointerCount=1, historySize=0, eventTime=35158623, downTime=35158623, deviceId=0, source=0x1002 }) 
03-11 16:32:06.931: D/GestureListener(5316): - onSingleTapConfirmed()