AppBarLayout elevation hides toolbar

问题:

I'm trying to disable the shadow below a transparent AppBarLayout/Toolbar. Here's the layout:

<android.support.design.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"     android:background="#000">      <android.support.design.widget.AppBarLayout         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:fitsSystemWindows="true"         android:background="@android:color/transparent"         android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">          <android.support.v7.widget.Toolbar             android:id="@+id/imagePreviewToolbar"             android:layout_width="match_parent"             android:layout_height="?attr/actionBarSize" />      </android.support.design.widget.AppBarLayout>      <include layout="@layout/content_image_preview" /> </android.support.design.widget.CoordinatorLayout> 

I already tried with

app:elevation="0dp" 

and

getSupportActionBar().setElevation(0); 

but that makes the UP arrow invisible. I also tried to remove the AppBarLayout and use only the Toolbar, but the problem persists.

Anyone has a solution?

---

EDIT:

Replacing the AppBarLayout + Toolbar combo with this code:

<android.support.v7.widget.Toolbar     android:id="@+id/imagePreviewToolbar"     android:layout_width="match_parent"     android:layout_height="?attr/actionBarSize"     android:background="@android:color/transparent"     android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"     app:popupTheme="@style/ThemeOverlay.AppCompat.Light"     app:elevation="0dp"/> 

partially fixed the problem. Now the Toolbar becomes invisible only when the device is in landscape mode! The Android Studio Layout Editor shows me the Toolbar in both orientations just fine, so I don't really know what the problem could be..

回答1:

after some tries i did find that ToolBar should be the last view in this case else if it will be first then the view coming after it will overlap it as it has height set to match_parent so try this way in layout.

Layout

<?xml version="1.0" encoding="utf-8"?> <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" >  <RelativeLayout     xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:layout_below="@+id/imagePreviewToolbar" >      <ImageView         android:id="@+id/image_preview"         android:layout_width="fill_parent"         android:layout_height="fill_parent"         android:background="@drawable/galacticos"         android:contentDescription="abc"         android:scaleType="fitCenter" />      <LinearLayout         android:id="@+id/actionBtns"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:layout_alignParentBottom="true"         android:orientation="horizontal"         android:padding="16dp" >          <ImageButton             android:id="@+id/setBackgroundBtn"             android:layout_width="match_parent"             android:layout_height="wrap_content"             android:layout_weight="1"             android:background="@null"             android:contentDescription="abc"             android:src="@drawable/ic_launcher" />          <ImageButton             android:id="@+id/downloadBtn"             android:layout_width="match_parent"             android:layout_height="wrap_content"             android:layout_weight="1"             android:background="?selectableItemBackgroundBorderless"             android:clickable="true"             android:contentDescription="abc"             android:src="@drawable/ic_launcher" />     </LinearLayout> </RelativeLayout>  <android.support.v7.widget.Toolbar     android:id="@+id/imagePreviewToolbar"     android:layout_width="match_parent"     android:layout_height="?attr/actionBarSize"     android:fitsSystemWindows="true"     app:popupTheme="@style/ThemeOverlay.AppCompat.Light"     app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" /> 

And don't forget to initialize this all and set your title to false to only show the toolBar back button:

Activity Code

@Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.test);      Toolbar mToolBar = (Toolbar) findViewById(R.id.imagePreviewToolbar);     setSupportActionBar(mToolBar);     getSupportActionBar().setDisplayHomeAsUpEnabled(true);     getSupportActionBar().setDisplayShowTitleEnabled(false);     getSupportActionBar().setHomeButtonEnabled(true);  } 

Pics

Hope i helped you.

回答2:

Make toolbar like this:

<android.support.design.widget.AppBarLayout                 android:id="@+id/myAppBar"                 android:layout_width="match_parent"                 android:layout_height="wrap_content"                 app:elevation="0dp"...>     </android.support.design.widget.AppBarLayout> 

And after that in your Activity;

findViewById(R.id.myAppBar).bringToFront(); 

文章来源: AppBarLayout elevation hides toolbar