NestedScrollView和onInterceptTouchEvent

时间:2015-09-21 15:38:54

标签: android ontouchevent nestedscrollview

我确实扩展了NestedScrollView和@Override方法: onTouchEvent onInterceptTouchEvent 。问题是super.onTouchEvent从不调用ACTION_DOWN(它由我的onIntereceptTouchEvent调用),因为NestedScrollView没有移动,我得到错误:

  

onTouchEvent中的pointerId = -1无效

当触发ACTION_DOWN时,指针id在NestedScrollView的onTouchEvent方法中设置。

mActivePointerId = MotionEventCompat.getPointerId(ev, 0);

我自己无法设置,重写整个onTouchEvent方法似乎是痛苦的计划。可以在这里使用帮助。当我单击不监听触摸事件的View时,NestedScrollView会移动(基本上,我的onInterecptTouchEvent方法没有被调用,而且在NestedScrollView onTouchEvent中处理了ACTION_DOWN)。

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    Log.i(LOGTAG, String.valueOf(ev.getAction()));

    final int action = MotionEventCompat.getActionMasked(ev);

    if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) {
        mIsBeingDragged = false;
        Log.i(LOGTAG, "is scrolling" + String.valueOf(mIsBeingDragged));
        return false; // Do not intercept touch event, let the child handle it
    }

    switch (action) {
        case MotionEvent.ACTION_DOWN: {
            mStartY = ev.getY();
            break;
        }
        case MotionEvent.ACTION_MOVE: {
            if (mIsBeingDragged) {
                return true;
            }

            final int yDiff = calculateDistanceY(ev);
            Log.d(LOGTAG, "y difference: y");
            if (yDiff > mTouchSlop) {
                mIsBeingDragged = true;
                return true;
            }
            break;
        }
    }
    return false;
}

@Override
public boolean onTouchEvent(MotionEvent ev) {
    Log.i(LOGTAG, "onTouchEvent");
    if (ev.getAction() == MotionEvent.ACTION_CANCEL || ev.getAction() == MotionEvent.ACTION_UP) {
        mIsBeingDragged = false;
    }

    return super.onTouchEvent(ev);
}

1 个答案:

答案 0 :(得分:3)

以下是修复我的问题的代码,我不得不撒谎:

@Override
public boolean onTouchEvent(MotionEvent ev) {
    Log.i(LOGTAG, "onTouchEvent");
    if (ev.getAction() == MotionEvent.ACTION_CANCEL || ev.getAction() == MotionEvent.ACTION_UP) {
        mIsBeingDragged = false;
    }

    if (mFirstOnTouchEvent) {
        ev.setAction(MotionEvent.ACTION_DOWN);
        ev.setLocation(mStartX, mStartY);
        mFirstOnTouchEvent = false;
    }

    return super.onTouchEvent(ev);
}

并在onInterceptTouchEvent中触发ACTION_DOWN时将mFirstOnTouchEvent设置为true