android 界面滑动顶部标题栏颜色渐变

使用RecyclerView进行滑动监听

@BindView(R.id.activity_myaccelate_recycler)

RecyclerViewmRecyclerView;

@BindView(R.id.activity_myaccelate_statusbar)

LinearLayoutliStatusbar;//状态栏布局

@BindView(R.id.activity_myaccelate_toptitle)

RelativeLayoutrlTopTitle;//顶部标题栏布局

@BindView(R.id.activity_myaccelate_line)

ViewrlTopTitleLine;//顶部标题栏布局分割线

@BindView(R.id.activity_myaccelate_leftbtn)

TextViewbtnLeft;//标题栏-左返回键

@BindView(R.id.activity_myaccelate_title)

TextViewtvTitle;//标题栏-标题

@BindView(R.id.activity_myaccelate_tvright)

TextViewbtnRight;//标题栏-右按钮

private int overallXScroll =0;

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

mRecyclerView.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);

int alpha =0;

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

            rlTopTitle.setBackgroundColor(Color.argb(0,252,252,252));

liStatusbar.setBackgroundColor(Color.argb(0,252,252,252));

tvTitle.setTextColor(Color.argb(255,255,255,255));

btnRight.setTextColor(Color.argb(255,255,255,255));

btnLeft.setBackgroundResource(R.drawable.title_whiteleft_selector);

rlTopTitleLine.setVisibility(View.GONE);

}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;

alpha = (int) (255 * scale);

rlTopTitle.setBackgroundColor(Color.argb(alpha,252,252,252));

liStatusbar.setBackgroundColor(Color.argb(alpha,252,252,252));

tvTitle.setTextColor(Color.argb(alpha,0,0,0));

btnRight.setTextColor(Color.argb(alpha,0,0,0));

btnLeft.setBackgroundResource(R.drawable.title_left_selector);

rlTopTitleLine.setVisibility(View.GONE);

}else {

if (alpha <255) {

rlTopTitle.setBackgroundColor(Color.argb(255,252,252,252));

liStatusbar.setBackgroundColor(Color.argb(255,252,252,252));

tvTitle.setTextColor(Color.argb(255,0,0,0));

btnRight.setTextColor(Color.argb(255,0,0,0));

}

btnLeft.setBackgroundResource(R.drawable.title_left_selector);

rlTopTitleLine.setVisibility(View.VISIBLE);

}

}

});