重绘自定义视图时，停止NestedScrollView从滚动到顶部

Question

我在NestedScrollView中有一个自定义视图。每次在视图上调用invalidate时，布局都会滚动到自定义视图的顶部。我希望重绘视图后滚动位置不变。知道如何做到这一点？

我尝试组合实现onScrollChangeListener和onGlobalLayoutListener以重新滚动到之前滚动的位置，但它不起作用。我在片段的onCreateView方法中有以下代码。

ViewTreeObserver observer = layoutView.getViewTreeObserver();

if (scrollListener != null) {
        observer.removeOnScrollChangedListener(scrollListener);
    } else  {
        scrollListener = new ViewTreeObserver.OnScrollChangedListener() {
            @Override
            public void onScrollChanged() {
                scrollX = layoutView.getScrollX();
                scrollY = layoutView.getScrollY();

            }
        };
    }

    observer.addOnScrollChangedListener(scrollListener);

    if (layoutListener != null) {
        observer.removeOnGlobalLayoutListener(layoutListener);
    } else {
        layoutListener = new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                if (customView != null && scrollY != 0 && getUserVisibleHint()) {
                    layoutView.setVerticalScrollbarPosition(scrollY);
            }
        };
    }

    observer.addOnGlobalLayoutListener(layoutListener);

以下是自定义视图的onDraw和onMeasure方法的代码。

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);

    if (pieces == null) {
        return;
    }

    int position = 0;

    for (int r = 0; r < rows; r++) {
        for (int c = 0; c < cols && position < pieces.length; c++) {
            Paint paint = (pieces[position] ? complete : empty);

            int left = c * stepSize + borderSize + margin;
            int right = left + stepSize - borderSize * 2;
            int top = r * stepSize + borderSize;
            int bottom = top + stepSize - borderSize * 2;

            canvas.drawRect(left + borderSize, top + borderSize,
                    right + borderSize, bottom + borderSize, paint);

            ++position;
        }
    }

}



@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    int width = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();

    cols = width / stepSize;

    rows = (int) Math.ceil((float) cells / (float) cols);
    margin = (width - cols * stepSize) / 2;

    int height = rows * stepSize;

    setMeasuredDimension(width, Math.max(width, height));


}