<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  xmlns:app="http://schemas.android.com/apk/res-auto" 
  android:layout_width="match_parent" 
  android:layout_height="match_parent" 
  android:fitsSystemWindows="true" > 
  <android.support.design.widget.AppBarLayout 
    android:id="@+id/abl_bar" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:fitsSystemWindows="true" > 
    <android.support.design.widget.CollapsingToolbarLayout 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:fitsSystemWindows="true" 
      app:layout_scrollFlags="scroll|exitUntilCollapsed|snap" 
      app:contentScrim="@color/blue_dark" > 
      <include 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:layout_marginTop="@dimen/toolbar_height" 
        app:layout_collapseMode="parallax" 
        app:layout_collapseParallaxMultiplier="0.7" 
        layout="@layout/life_pay" /> 
      <android.support.v7.widget.Toolbar 
        android:layout_width="match_parent" 
        android:layout_height="@dimen/toolbar_height" 
        app:layout_collapseMode="pin" 
        app:contentInsetLeft="0dp" 
        app:contentInsetStart="0dp" > 
        <include 
          android:id="@+id/tl_expand" 
          android:layout_width="match_parent" 
          android:layout_height="match_parent" 
          layout="@layout/toolbar_expand" /> 
        <include 
          android:id="@+id/tl_collapse" 
          android:layout_width="match_parent" 
          android:layout_height="match_parent" 
          layout="@layout/toolbar_collapse" 
          android:visibility="gone" /> 
      </android.support.v7.widget.Toolbar> 
    </android.support.design.widget.CollapsingToolbarLayout> 
  </android.support.design.widget.AppBarLayout> 
  <android.support.v7.widget.RecyclerView 
    android:id="@+id/rv_content" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:layout_marginTop="10dp" 
    app:layout_behavior="@string/appbar_scrolling_view_behavior" /> 
</android.support.design.widget.CoordinatorLayout> 

public class AlipayActivity extends AppCompatActivity implements OnOffsetChangedListener { 
  private final static String TAG = "AlipayActivity"; 
  private AppBarLayout abl_bar; 
  private View tl_expand, tl_collapse; 
  private View v_expand_mask, v_collapse_mask, v_pay_mask; 
  private int mMaskColor; 
  private RecyclerView rv_content; 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_alipay); 
    mMaskColor = getResources().getColor(R.color.blue_dark); 
    rv_content = (RecyclerView) findViewById(R.id.rv_content); 
    rv_content.setLayoutManager(new GridLayoutManager(this, 4)); 
    rv_content.setAdapter(new LifeAdapter(this, LifeItem.getDefault())); 
    abl_bar = (AppBarLayout) findViewById(R.id.abl_bar); 
    tl_expand = (View) findViewById(R.id.tl_expand); 
    tl_collapse = (View) findViewById(R.id.tl_collapse); 
    v_expand_mask = (View) findViewById(R.id.v_expand_mask); 
    v_collapse_mask = (View) findViewById(R.id.v_collapse_mask); 
    v_pay_mask = (View) findViewById(R.id.v_pay_mask); 
    abl_bar.addOnOffsetChangedListener(this); 
  } 
  @Override 
  public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) { 
    Log.d(TAG, "verticalOffset="+verticalOffset); 
    int offset = Math.abs(verticalOffset); 
    int total = appBarLayout.getTotalScrollRange(); 
    int alphaIn = offset; 
    int alphaOut = (200-offset)<0?0:200-offset; 
    int maskColorIn = Color.argb(alphaIn, Color.red(mMaskColor), 
        Color.green(mMaskColor), Color.blue(mMaskColor)); 
    int maskColorInDouble = Color.argb(alphaIn*2, Color.red(mMaskColor), 
        Color.green(mMaskColor), Color.blue(mMaskColor)); 
    int maskColorOut = Color.argb(alphaOut*2, Color.red(mMaskColor), 
        Color.green(mMaskColor), Color.blue(mMaskColor)); 
    if (offset <= total / 2) { 
      tl_expand.setVisibility(View.VISIBLE); 
      tl_collapse.setVisibility(View.GONE); 
      v_expand_mask.setBackgroundColor(maskColorInDouble); 
    } else { 
      tl_expand.setVisibility(View.GONE); 
      tl_collapse.setVisibility(View.VISIBLE); 
      v_collapse_mask.setBackgroundColor(maskColorOut); 
    } 
    v_pay_mask.setBackgroundColor(maskColorIn); 
  } 
}