Android开发三步实现控件悬浮效果

原理很简单，用RecyclerView addHeaderView的方式实现，实现步骤：

1.添加依赖

 compile 'com.github.CymChad:BaseRecyclerViewAdapterHelper:2.9.14'
 compile 'com.android.support:recyclerview-v7:25.1.0'

导入BaseRecyclerViewAdapterHelper，用于RecyclerView添加HeaderView;

2.布局，用标签include，写入需要悬浮的view；主界面用帧布局FrameLayout

<FrameLayout
       android:layout_width="match_parent"
       android:layout_height="match_parent">
       <android.support.v7.widget.RecyclerView
           android:id="@+id/main_recycler"
           android:layout_width="match_parent"
           android:layout_height="match_parent"/>
    <include layout="@layout/include_header_product"/>
   </FrameLayout> 

然后布局headerView

3.逻辑，滑动的时候，对RecyclerView进行滑动监听然后在onScrollStateChanged(RecyclerView recyclerView, int newState)方法里监听悬浮View在 屏幕上Y轴位移，在onScrolled(RecyclerView recyclerView, int dx, int dy)里不停的获取headerView里面悬浮标签在屏幕上Y轴位移, 进行判断悬浮view的显示或隐藏 if (mHeaderView == null) return; int getTop = mHeaderView.getDistanceY(); if (getTop <= imageY) { mImageView.setVisibility(View.VISIBLE); } else { mImageView.setY(0); mImageView.setVisibility(View.GONE); }