标题栏随RecyclerView滑动动态修改透明度

来源：互联网发布：邮政内控优化心得体会编辑：程序博客网时间：2024/06/07 23:27

标题栏随RecyclerView滑动动态修改透明度,其使用是使标题栏覆盖在RecyclerView上方，添加以下方法监听滑动时y轴的变化

    private int height = 640;// 滑动开始变色的高,真实项目中此高度是由广告轮播或其他首页view高度决定    private int overallXScroll = 0;    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {            @Override            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {                super.onScrollStateChanged(recyclerView, newState);            }            @Override            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {                super.onScrolled(recyclerView, dx, dy);                overallXScroll = overallXScroll + dy;// 累加y值 解决滑动一半y值为0                if (overallXScroll <= 0) {   //设置标题的背景颜色                    llSearch.setBackgroundColor(Color.argb((int) 0, 41, 193, 246));                } else if (overallXScroll > 0 && overallXScroll <= height) { //滑动距离小于banner图的高度时，设置背景和字体颜色颜色透明度渐变                    float scale = (float) overallXScroll / height;                    float alpha = (255 * scale);                    llSearch.setBackgroundColor(Color.argb((int) alpha, 41, 193, 246));                } else {                    llSearch.setBackgroundColor(Color.argb((int) 255, 41, 193, 246));                }            }        });

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