android - View 的 Ontouch 方法中的单点触摸检测

Question

我需要在我的自定义 View 的 ontouch 方法中进行单点触摸检测。我尝试在 ACTION-DOWN 和 ACTION-UP 和 ACTION-UP 中获取 x 和 y 值.

我的代码如下

@Override
public boolean onTouchEvent(MotionEvent ev) {
   if (!mSupportsZoom && !mSupportsPan) return false;

    mScaleDetector.onTouchEvent(ev);

    final int action = ev.getAction();
    switch (action & MotionEvent.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN: {
        final float x = ev.getX();
        final float y = ev.getY();

        mLastTouchX = x;  //here i get x and y values in action down
        mLastTouchY = y;
        mActivePointerId = ev.getPointerId(0);

        break;
    }

    case MotionEvent.ACTION_MOVE: {
        final int pointerIndex = ev.findPointerIndex(mActivePointerId);
        final float x = ev.getX(pointerIndex);
        final float y = ev.getY(pointerIndex);

        if (mSupportsPan && !mScaleDetector.isInProgress()) {
            final float dx = x - mLastTouchX;
            final float dy = y - mLastTouchY;

            mPosX += dx;
            mPosY += dy;
            //mFocusX = mPosX;
            //mFocusY = mPosY;

            invalidate();
        }

        mLastTouchX = x;
        mLastTouchY = y;

        break;
    }

    case MotionEvent.ACTION_UP: {

        final float x = ev.getX();
        final float y = ev.getY();

        touchupX=x;   //here is get x and y values at action up
        touchupY=y; 

        if(mLastTouchX == touchupX && mLastTouchY == touchupY){  //my condition if both the x and y values are same .

            PinchZoomPanActivity2.tapped1(this.getContext(), 100); //my method if the singletap is detected

        }
        else{

        }

        mActivePointerId = INVALID_POINTER_ID;

        break;
    }

    case MotionEvent.ACTION_CANCEL: {
        mActivePointerId = INVALID_POINTER_ID;
        break;
    }

    case MotionEvent.ACTION_POINTER_UP: {
        final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) 
                >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
        final int pointerId = ev.getPointerId(pointerIndex);
        if (pointerId == mActivePointerId) {

            final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
            mLastTouchX = ev.getX(newPointerIndex);
            mLastTouchY = ev.getY(newPointerIndex);
            mActivePointerId = ev.getPointerId(newPointerIndex);
        }
        break;
    }
    }

    return true;
}

但我无法完成它。我的意思是在每次操作时都会调用我的方法。即使 actionup 和 actiondown 的 x 和 y 值不相同。而且我认为当我们用手指在屏幕上触摸时，我还需要为单击设置一些范围。谁能给我一些建议？

Answer 1

要在 android 中检测 Single Tap 和 Double Tap，我使用以下方法:

class GestureTap extends GestureDetector.SimpleOnGestureListener {
    @Override
    public boolean onDoubleTap(MotionEvent e) {
        Log.i("onDoubleTap :", "" + e.getAction());
        return true;
   }

    @Override
    public boolean onSingleTapConfirmed(MotionEvent e) {
        Log.i("onSingleTap :", "" + e.getAction());
        return true;
    }
}

在 GestureDetector 的构造函数中使用它:

detector = new GestureDetector(this, new GestureTap());

并在onTouch监听器中添加如下代码

@Override
public boolean onTouchEvent(MotionEvent event) {

    detector.onTouchEvent(event);

    return true;
}