如何检测Android中的双指点按？

我需要在我正在处理的 Android应用中检测双指点击.我也使用ScaleGestureDetector和GestureDetector来检测水龙头,双击,长按和缩放.

在我的onTouchEvent方法中,我有：

@Override
public Boolean onTouchEvent(MotionEvent event) {
    scaleGestureDetector.onTouchEvent(event);
    gestureDetector.onTouchEvent(event);

    switch (event.getActionMasked()) {
    case MotionEvent.ACTION_DOWN:
        activePointerId = event.getPointerId(0);
        break;
    .
    .
    .
    case MotionEvent.ACTION_POINTER_UP:
        int pointerId = event.getPointerId(event.getActionIndex());

        if (pointerId == activePointerId) {
            // change active pointer
        } else if (!scaleDetector.isInProgress() && (event.getPointerCount() == 2)) {
            // handle two-finger tap
        }
        break;
    .
    .
    .

问题是,刻度也被检测为双指敲击.有关解决此问题的任何想法？谢谢！