Android之Toolbar标题栏颜色渐变

仅仅调用RecyclerView中的api即可

mRv.setOnScrollListener(new RecyclerView.OnScrollListener() {
    int titleHeight;
    @Override
    public void onScrolled(RecyclerView rv, int dx, int dy) {
        super.onScrolled(rv, dx, dy);
        titleHeight = titleHeight == 0 ? titleView.getMeasuredHeight() : titleHeight;
        if (rv.computeVerticalScrollOffset() <= titleHeight) {
            float rate = (float) rv.computeVerticalScrollOffset() / (float) titleHeight;
            titleView.setAlpha(rate);
        }
    }
});

这个titleHeight是标题栏的高度，然后这里的逻辑是垂直下滑的位移除以标题栏的高度就是比例

非常简单

效果图