Android工具欄沒有海拔

Question

我的主佈局有一個CoordinatorLayout，它有一個AppBarLayout,CollapsingToolbarLayout,Toolbar和一個TabLayout。

但是，工具欄不顯示陰影。

這是我的佈局：

<android.support.v4.widget.DrawerLayout 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:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:layout_gravity="right" 
    android:focusableInTouchMode="true" 
    android:clickable="true" 
    android:layoutDirection="rtl" 
    android:fitsSystemWindows="true" 
    android:id="@+id/drawer_layout"> 
    <android.support.design.widget.CoordinatorLayout 
     android:id="@+id/mainCoordinatorLayout" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:fitsSystemWindows="true" 
     android:layoutDirection="rtl" 
     android:background="#eeeeee" 
     android:clickable="true"> 
     <android.support.design.widget.AppBarLayout 
      android:layout_height="wrap_content" 
      android:layout_width="match_parent" 
      android:fitsSystemWindows="true" 
      app:layout_behavior="torathamachane.DisableableAppBarLayoutBehavior" 
      android:id="@+id/toolbar_layout"> 
      <android.support.design.widget.CollapsingToolbarLayout 
       android:id="@+id/collapsing_toolbar" 
       android:layout_width="match_parent" 
       android:layout_height="200dp" 
       android:fitsSystemWindows="true" 
       app:contentInsetStartWithNavigation="0dp" 
       app:layout_scrollFlags="scroll|exitUntilCollapsed" 
       app:contentScrim="?attr/colorPrimary" 
       app:collapsedTitleGravity="right|top" 
       app:expandedTitleGravity="bottom|right" 
       app:expandedTitleMarginBottom="44dp" 
       app:collapsedTitleTextAppearance="@style/CollapsedTitleTextAppearance" 
       app:expandedTitleTextAppearance="@style/ExpandedTitleTextAppearance" 
       app:expandedTitleMarginEnd="0dp" 
       app:expandedTitleMarginStart="30dp"> 
       <ImageView 
        android:id="@+id/headerImage" 
        android:layout_width="match_parent" 
        android:layout_height="match_parent" 
        android:scaleType="centerCrop" 
        android:fitsSystemWindows="true" /> 
       <View 
        android:fitsSystemWindows="true" 
        android:layout_width="match_parent" 
        android:layout_height="100dp" 
        android:background="@drawable/scrim_top" 
        app:layout_collapseMode="pin" /> 
       <View 
        android:fitsSystemWindows="true" 
        android:layout_width="match_parent" 
        android:layout_height="112dp" 
        android:layout_gravity="bottom" 
        android:layout_alignBottom="@+id/headerImage" 
        android:background="@drawable/scrim_bottom" /> 
       <android.support.v7.widget.Toolbar 
        android:id="@+id/toolbar" 
        android:layout_width="match_parent" 
        android:layout_height="56dp" 
        app:titleTextColor="@color/White" 
        android:layout_gravity="right" 
        android:layoutDirection="rtl" 
        app:layout_collapseMode="pin" 
        app:popupTheme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" 
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" 
        app:contentInsetStartWithNavigation="0dp" 
        app:titleMarginTop="13dp"> 
        <LinearLayout 
         android:id="@+id/Location_Spinner_Layout" 
         android:orientation="horizontal" 
         android:clickable="true" 
         android:layout_width="wrap_content" 
         android:layout_height="wrap_content" 
         android:visibility="gone" 
         android:layout_marginLeft="-15dp"> 
         <include 
          android:id="@+id/toolbar_header_view" 
          layout="@layout/toolbar_header_view" 
          android:layout_height="wrap_content" 
          android:layout_width="wrap_content" 
          android:layout_marginLeft="@dimen/header_view_end_margin_left" 
          android:visibility="invisible" /> 
         <View 
          android:layout_width="0dp" 
          android:layout_height="0dp" 
          android:layout_weight="1" /> 
         <TextView 
          android:id="@+id/dateText" 
          android:layout_width="wrap_content" 
          android:layout_height="wrap_content" 
          android:textColor="@color/White" 
          android:background="?selectableItemBackgroundBorderless" 
          android:layout_gravity="center_vertical" 
          android:gravity="center" 
          android:textSize="13sp" /> 
        </LinearLayout> 
       </android.support.v7.widget.Toolbar> 
       <android.support.design.widget.TabLayout 
        android:id="@+id/libraryTabs" 
        android:layout_width="match_parent" 
        android:layout_height="?attr/actionBarSize" 
        android:layout_gravity="bottom" 
        app:tabIndicatorHeight="3dp" 
        android:layoutDirection="ltr" 
        android:background="?attr/colorPrimary" 
        app:tabIndicatorColor="@android:color/white" 
        android:theme="@style/ThemeOverlay.AppCompat.Dark" 
        app:tabMode="fixed" 
        app:tabGravity="fill" /> 
      </android.support.design.widget.CollapsingToolbarLayout> 
     </android.support.design.widget.AppBarLayout> 

什麼是錯我的佈局？

Answer 1

試試這個我也有同樣的問題，我的作品

final AppBarLayout.LayoutParams params = (AppBarLayout.LayoutParams) 
      toolbar.getLayoutParams(); 
    params.setScrollFlags(0); 
    toolbar.setLayoutParams(params);