/** 
 * Author：Biligle. 
 * 自定義布局 
 */ 
 
public class MyViewGroup extends ViewGroup { 
 
 private MyViewGroupListener listener;//接口，監(jiān)聽滑動(dòng)事件 
 private int vertical = 0;//布局距離頂端距離（默認(rèn)0） 
 
 public MyViewGroup(Context context) { 
 super(context); 
 } 
 
 public MyViewGroup(Context context, AttributeSet attrs) { 
 super(context, attrs); 
 } 
 
 public MyViewGroup(Context context, AttributeSet attrs, int defStyleAttr) { 
 super(context, attrs, defStyleAttr); 
 } 
 
 @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP) 
 public MyViewGroup(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { 
 super(context, attrs, defStyleAttr, defStyleRes); 
 } 
 
 
 private int downY = 0;//按下時(shí)的點(diǎn) 
 private int slide = 0;//最終移動(dòng)距離 
 @Override 
 public boolean onTouchEvent(MotionEvent event) { 
 switch (event.getAction()){ 
  case MotionEvent.ACTION_DOWN: 
  downY = (int) event.getY(); 
  break; 
  case MotionEvent.ACTION_MOVE: 
  slide = downY - (int)event.getY(); 
  if(slide < 0){//下滑 
   vertical = listener.marginTop(Math.abs(slide)); 
  }else if(slide > 0){//上滑 
   vertical = listener.marginTop(-slide); 
  } 
  break; 
  case MotionEvent.ACTION_UP: 
  if(vertical < 300){ 
   //布局距離屏幕頂部小于300，就讓布局充滿整個(gè)屏幕 
   vertical = listener.marginTop(0); 
  } 
  break; 
 } 
 return true; 
 } 
 
 /** 
 * 測(cè)量子View 
 * @param widthMeasureSpec 
 * @param heightMeasureSpec 
 */ 
 @Override 
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 
 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 
 for (int i = 0; i < getChildCount(); i++) { 
  View child = getChildAt(i); 
  //系統(tǒng)測(cè)量 
  measureChild(child, widthMeasureSpec, heightMeasureSpec); 
 } 
 } 
 
 /** 
 * 安排子View的位置 
 * @param changed 
 * @param l 左邊距 
 * @param t 上邊距 
 * @param r 右邊距 
 * @param b 下邊距 
 */ 
 @Override 
 protected void onLayout(boolean changed, int l, int t, int r, int b) { 
 int left = 0, top = 0, right = 0, bottom = 0; 
 for (int i = 0; i < getChildCount(); i++) { 
  View child = getChildAt(i); 
  right = left + child.getMeasuredWidth(); 
  bottom = top + child.getMeasuredHeight(); 
  child.layout(left, top, right, bottom); 
 } 
 } 
 
 public void setListener(MyViewGroupListener listener){ 
 this.listener = listener; 
 } 
 
 interface MyViewGroupListener { 
 /** 
  * 設(shè)置topMargin，上下滑動(dòng)時(shí)觸發(fā) 
  * @param slide 滑動(dòng)距離 
  * @return 當(dāng)前上邊距 
  */ 
 int marginTop(int slide); 
 } 
}

public class MainActivity extends AppCompatActivity implements MyViewGroup.MyViewGroupListener{ 
 
 /** 自定義布局（外層布局）*/ 
 private MyViewGroup myViewGroup; 
 /** 兩個(gè)圓形圖（在外層布局）*/ 
 private ImageView iv1,iv2/*,cloud*/; 
 /** 包裹圓形圖的布局*/ 
 private RelativeLayout relativeLayout; 
 /** 外層布局參數(shù)類（這里用到了params.topMargin：上邊距）*/ 
 private ViewGroup.MarginLayoutParams params; 
 /** 透明值（改變兩個(gè)圓圖的透明值）*/ 
 private float f; 
 /** 左右內(nèi)邊距（改變RelativeLayout內(nèi)邊距）*/ 
 private int p; 
 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
 super.onCreate(savedInstanceState); 
 setContentView(R.layout.activity_main); 
 myViewGroup = (MyViewGroup) findViewById(R.id.my); 
 myViewGroup.setListener(this); 
 iv1 = (ImageView) findViewById(R.id.iv1); 
 iv2 = (ImageView) findViewById(R.id.iv2); 
 relativeLayout = (RelativeLayout) findViewById(R.id.relative); 
 params = (ViewGroup.MarginLayoutParams) myViewGroup.getLayoutParams(); 
 //初始化動(dòng)畫（自動(dòng)下滑一段兒距離），我這里寫死了900 
 ObjectAnimator animator = ObjectAnimator.ofFloat(myViewGroup,"translationY", 900); 
 animator.setDuration(2000); 
 animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { 
  @Override 
  public void onAnimationUpdate(ValueAnimator animation) { 
  float y = (float)animation.getAnimatedValue(); 
  f = y/800; 
  p = (int) y/3; 
  alpha(f); 
  padding(p); 
  } 
 }); 
 animator.start(); 
// cloud = (ImageView) findViewById(R.id.cloud); 
 } 
 
 
 /** 
 * 設(shè)置上邊距 
 * @param slide 滑動(dòng)距離 
 * @return 返回下滑布局，距離屏幕左上角的垂直距離 
 */ 
 @Override 
 public int marginTop(int slide) { 
 params.topMargin += slide; 
 myViewGroup.setLayoutParams(params); 
 int vertical = (900 + params.topMargin); 
 if(slide == 0){ 
  //為了隱藏兩張圓圖，所以把Relativelayout的高度一并減除。 
  params.topMargin -= (vertical+relativeLayout.getHeight()); 
  myViewGroup.setLayoutParams(params); 
 } 
 float alpha = f + (float) params.topMargin/800;//自定義一個(gè)算法 
 alpha(alpha); 
 int padding = p + params.topMargin/3;//自定義一個(gè)算法 
 padding(padding); 
 return vertical; 
 } 
 
 /** 
 * 設(shè)置透明度 
 * @param alpha 透明值 
 */ 
 public void alpha(float alpha) { 
 iv1.setAlpha(alpha); 
 iv2.setAlpha(alpha); 
 } 
 
 /** 
 * 設(shè)置左右邊距 
 * @param padding 邊距值 
 */ 
 public void padding(int padding) { 
 relativeLayout.setPadding(padding, 0, padding, 0); 
 } 

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout 
 xmlns:android="http://schemas.android.com/apk/res/android" 
 xmlns:app="http://schemas.android.com/apk/res-auto" 
 xmlns:tools="http://schemas.android.com/tools" 
 android:id="@+id/activity_main" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 tools:context="com.wgl.viewgroup1.MainActivity"> 
 <ImageView 
 android:id="@+id/iv" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 android:src="@mipmap/pic" 
 android:scaleType="fitXY"/> 
 <!--<ImageView--> 
  <!--android:id="@+id/cloud"--> 
  <!--android:layout_width="wrap_content"--> 
  <!--android:layout_height="wrap_content"--> 
  <!--android:layout_centerHorizontal="true"--> 
  <!--android:alpha="0.8"--> 
  <!--android:src="@mipmap/cloud3"--> 
  <!--android:clickable="true"/>--> 
 
 <com.wgl.viewgroup1.MyViewGroup 
 android:id="@+id/my" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 android:alpha="0.8" 
 android:layout_alignParentTop="true"> 
 <LinearLayout 
  android:layout_width="match_parent" 
  android:layout_height="match_parent" 
  android:orientation="vertical"> 
  <RelativeLayout 
  android:id="@+id/relative" 
  android:layout_width="match_parent" 
  android:layout_height="wrap_content" 
  android:orientation="horizontal"> 
  <com.wgl.viewgroup1.CircleImageView 
   android:id="@+id/iv1" 
   android:layout_width="wrap_content" 
   android:layout_height="wrap_content" 
   android:src="@mipmap/iv1" 
   app:civ_border_width="2dp" 
   app:civ_border_color="@color/colorAccent" 
   android:layout_alignParentLeft="true"/> 
 
  <com.wgl.viewgroup1.CircleImageView 
   android:id="@+id/iv2" 
   android:layout_width="wrap_content" 
   android:layout_height="wrap_content" 
   android:src="@mipmap/iv2" 
   app:civ_border_width="2dp" 
   app:civ_border_color="@color/colorAccent" 
   android:layout_alignParentRight="true"/> 
  </RelativeLayout> 
  <LinearLayout 
  android:layout_width="match_parent" 
  android:layout_height="match_parent" 
  android:alpha="0.8" 
  android:background="@color/colorPrimary"> 
 
  </LinearLayout> 
 </LinearLayout> 
 
 </com.wgl.viewgroup1.MyViewGroup> 
</RelativeLayout>