三步实现Android悬浮效果!!!
接下来就是实现效果,如图所示
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<ImageView android:layout_width="wrap_content" android:src="@mipmap/img_header_category" android:adjustViewBounds="true" android:layout_height="wrap_content"/> <include layout="@layout/include_header_product"/>
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，核心代码：int[] location = new int[2]; mImageView.getLocationOnScreen(location); int y = location[1]; imageY = y;
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，核心代码：if (mHeaderView == null) return; int getTop = mHeaderView.getDistanceY(); if (getTop <= imageY) { mImageView.setVisibility(View.VISIBLE); } else { mImageView.setY(0); mImageView.setVisibility(View.GONE); }