Android MotionEvent.getActionIndex() 和 MultiTouch

Question

我试图在事件 MotionEvent.ACTION_MOVE 发生时获取指针 id。

我通过调用 event.getActionIndex() 来做到这一点，但对于第二个、第三个、第四个和第五个手指，它总是返回 0。

我在 Galaxy S I9000 上使用 Gingerbread 2.3.3

这是我的代码

switch (event.getActionMasked()) {
case MotionEvent.ACTION_MOVE: {
    Log.d("D","  getActionIndex()="+event.getActionIndex());
    };break;
}

这是调试结果

05-02 19:20:08.628: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=1
05-02 19:20:08.781: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=1
05-02 19:20:08.820: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=1
05-02 19:20:08.914: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=1
05-02 19:20:09.070: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=2
05-02 19:20:09.187: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=2
05-02 19:20:09.324: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=2
05-02 19:20:09.460: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=2
05-02 19:20:09.523: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=2
05-02 19:20:09.542: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=2
05-02 19:20:09.679: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=3
05-02 19:20:09.703: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=3
05-02 19:20:09.847: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=3
05-02 19:20:10.117: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=3
05-02 19:20:10.261: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=4
05-02 19:20:10.281: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=4
05-02 19:20:10.304: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=4
05-02 19:20:10.371: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=4
05-02 19:20:10.410: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=4
05-02 19:20:10.433: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=4
05-02 19:20:10.519: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=4
05-02 19:20:10.558: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=4
05-02 19:20:10.613: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=3
05-02 19:20:10.640: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=2
05-02 19:20:10.656: DEBUG/D(4534): getActionIndex()=0  getPointerCount()=1

Answer 1

我使用 3 种方法来委托鼠标事件的责任。它在我的 2.3 HTC Desire S 上运行良好。它能够捕获多个触摸事件。

public void processMouseMove(int mouseX, int mouseY, int pid)
public void processMouseDown(int mouseX, int mouseY, int pid)
public void processMouseUp(int mouseX, int mouseY, int pid)


public boolean onTouch(View v, MotionEvent event) { 
    int p = event.getActionIndex();
    switch(event.getActionMasked()){
        case MotionEvent.ACTION_DOWN:
        case MotionEvent.ACTION_POINTER_DOWN:
            processMouseDown((int)event.getX(p), (int)event.getY(p), event.getPointerId(p));                
        break;              
        case MotionEvent.ACTION_POINTER_UP:                 
        case MotionEvent.ACTION_UP:
            processMouseUp((int)event.getX(p), (int)event.getY(p), event.getPointerId(p));
            break;
        case MotionEvent.ACTION_MOVE:
            final int historySize = event.getHistorySize();
            final int pointerCount = event.getPointerCount();
            for (int h = 0; h < historySize; h++) {
                 for (int p1 = 0; p1 < pointerCount; p1++) {
                    processMouseMove((int)event.getHistoricalX(p1, h), (int)event.getHistoricalY(p1, h), event.getPointerId(p1));
                 }
            }
            for (int p1 = 0; p1 < event.getPointerCount(); p1++) {

                processMouseMove((int)event.getX(p1), (int)event.getY(p1), event.getPointerId(p1));
            }
    }
    return true;
}

Answer 2

我正在使用这段代码来转储事件，并且效果很好。

/** Show an event in the LogCat view, for debugging */
private void dumpEvent(MotionEvent event) {
   String names[] = { "DOWN" , "UP" , "MOVE" , "CANCEL" , "OUTSIDE" ,
      "POINTER_DOWN" , "POINTER_UP" , "7?" , "8?" , "9?" };
   StringBuilder sb = new StringBuilder();
   int action = event.getAction();
   int actionCode = action & MotionEvent.ACTION_MASK;
   sb.append("event ACTION_" ).append(names[actionCode]);
   if (actionCode == MotionEvent.ACTION_POINTER_DOWN
         || actionCode == MotionEvent.ACTION_POINTER_UP) {
      sb.append("(pid " ).append(
      action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
      sb.append(")" );
   }
   sb.append("[" );
   for (int i = 0; i < event.getPointerCount(); i++) {
      sb.append("#" ).append(i);
      sb.append("(pid " ).append(event.getPointerId(i));
      sb.append(")=" ).append((int) event.getX(i));
      sb.append("," ).append((int) event.getY(i));
      if (i + 1 < event.getPointerCount())
         sb.append(";" );
   }
   sb.append("]" );
   Log.d(TAG, sb.toString());
}

我把它取下来这篇 ZDNET 文章，所以我不能将其归功于它。我在 Android 3.0 上运行，但示例代码最初是为早期版本的 Android 编写的，因此它也应该适合您。

看起来您需要调用 getPointerId 而不是 getActionIndex。

Answer 3

使用 MotionEventCompat。

// get pointer index from the event object

int pointerIndex = MotionEventCompat.getActionIndex(event);

// get masked (not specific to a pointer) action

int maskedAction = MotionEventCompat.getActionMasked(event);