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一、效果图

二、实现

关键 behaviro:

**
 *
 *   自定义Behavior ：实现RecyclerView(或者其他可滑动View，如：NestedScrollView) 滑动覆盖header 的效果
 * Created by zhouwei on 16/12/19.
 */
public class CoverHeaderScrollBehavior extends CoordinatorLayout.Behavior<View> {
    public static final String TAG = "CoverHeaderScroll";
    public CoverHeaderScrollBehavior(Context context, AttributeSet attributeSet){
        super(context,attributeSet);
    }
    @Override
    public boolean onLayoutChild(CoordinatorLayout parent, View child, int layoutDirection) {
        Log.i(TAG,"onLayoutChild.....");
        CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) child.getLayoutParams();
        if(params!=null && params.height == CoordinatorLayout.LayoutParams.MATCH_PARENT){
            child.layout(0,0,parent.getWidth(),parent.getHeight());
            child.setTranslationY(getHeaderHeight());
            return true;
        }
        return super.onLayoutChild(parent, child, layoutDirection);
    }
    @Override
    public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, View child, View directTargetChild, View target, int nestedScrollAxes) {
        return (nestedScrollAxes & ViewCompat.SCROLL_AXIS_VERTICAL) != 0;
    }
    @Override
    public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, View child, View target, int dx, int dy, int[] consumed) {
        super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed);
        // 在这个方法里面只处理向上滑动
        if(dy < 0){
            return;
        }
        float transY =  child.getTranslationY() - dy;
        Log.i(TAG,"transY:"+transY+"++++child.getTranslationY():"+child.getTranslationY()+"---->dy:"+dy);
        if(transY > 0){
            child.setTranslationY(transY);
            consumed[1]= dy;
        }
    }
    @Override
    public void onNestedScroll(CoordinatorLayout coordinatorLayout, View child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
        // 在这个方法里只处理向下滑动
        if(dyUnconsumed >0){
            return;
        }
        float transY = child.getTranslationY() - dyUnconsumed;
        Log.i(TAG,"------>transY:"+transY+"****** child.getTranslationY():"+child.getTranslationY()+"--->dyUnconsumed"+dxUnconsumed);
        if(transY > 0 && transY < getHeaderHeight()){
            child.setTranslationY(transY);
        }
    }
    /**
     * 获取Header 高度
     * @return
     */
    public int getHeaderHeight(){
        return Objects.requireNonNull(App.Companion.getMContext()).getResources().getDimensionPixelOffset(R.dimen.m160);
    }
}

布局文件：

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <ImageView
        android:layout_width="match_parent"
        android:layout_height="@dimen/m160"
        android:scaleType="centerCrop"
        android:src="@mipmap/wuhuang"
        />
    <androidx.core.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/white"
        app:layout_behavior=".design.behavior.scroll.CoverHeaderScrollBehavior"
        >
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="@dimen/m12"
            android:text="@string/large_text" />
    </androidx.core.widget.NestedScrollView>
</androidx.coordinatorlayout.widget.CoordinatorLayout>

三、地址和参考

demo
Material Design 之 Behavior的使用和自定义Behavior