Android：Appcompat 21如何在操作栏上添加阴影

Question

I add the new material design actionbar from the new appcompat and I use the new toolbar widget. I set a custom background on the toolbar on xml but my problem is that the drop shadow from the actionbar is not displayed. Do you know how to do this?

Toolbar code

<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/my_awesome_toolbar"
    android:layout_height="wrap_content"
    android:layout_width="match_parent"
    android:minHeight="?attr/actionBarSize"
    android:background="@drawable/ab_background_textured"
    app:theme="@style/MyTheme"
    app:popupTheme="@style/MyTheme.Popup"/>

MyTheme style

<style name="MyTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="android:textColorPrimary">@color/abc_primary_text_material_dark</item>
    <item name="actionMenuTextColor">@color/abc_primary_text_material_dark</item>
    <item name="android:textColorSecondary">#ffff8800</item>
</style>

MyTheme.Popup style

<style name="MyTheme.Popup" parent="ThemeOverlay.AppCompat.Dark">
    <item name="android:textColor">#ffffff</item>
</style>

Update

Like @Justin Powell suggested I add the actionBarStyle on my theme but still there is no drop shadow.

MyTheme style(Updated)

<style name="MyTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="android:textColorPrimary">@color/abc_primary_text_material_dark</item>
    <item name="actionMenuTextColor">@color/abc_primary_text_material_dark</item>
    <item name="android:textColorSecondary">#ffff8800</item>
    <item name="android:actionBarStyle">@style/Widget.AppCompat.Light.ActionBar.Solid.Inverse</item>
</style>

Answer 1

I found the solution in the Google IO app to be acceptable for myself, but saw no blog or Stackoverflow post fully explaining it. What you can do is grab their Apache 2 licensed drawer shadow asset from https://github.com/google/iosched/blob/36d88985ff6813fa9035530cd426393720a6f7b4/android/src/main/res/drawable-xxhdpi/bottom_shadow.9.png and then in the layout of your Activity:

<RelativeLayout android:layout_width="match_parent"
                android:layout_height="match_parent">
    <include android:id="@+id/toolbar"
             layout="@layout/toolbar"/>

    <FrameLayout android:layout_width="match_parent"
                 android:layout_height="match_parent"
                 android:layout_below="@id/toolbar"
                 android:foreground="@drawable/header_shadow">
    <!-- YOUR STUFF HERE -->
    </FrameLayout>
</RelativeLayout>

Whereas header shadow is

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <item name="header_shadow" type="drawable">@drawable/bottom_shadow</item>
</resources>

for API levels <21. Just like https://github.com/google/iosched/blob/8c798c58e592b8a25111610e216c7f3ee74c3a42/android/src/main/res/values/refs.xml and https://github.com/google/iosched/blob/8c798c58e592b8a25111610e216c7f3ee74c3a42/android/src/main/res/values-v21/refs.xml .

And to be elaborate, here is toolbar.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:elevation="4dp"
        app:theme="@style/ToolbarTheme"
        app:popupTheme="@style/AppTheme"/>

Answer 2

For pre-5.0 layouts, you can add the shadow back to the content below the toolbar by adding foreground="?android:windowContentOverlay" to the content's FrameLayout.

For example:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
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:orientation="vertical"
>

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:minHeight="?attr/actionBarSize"
    app:theme="@style/ThemeOverlay.AppCompat.ActionBar" />

<FrameLayout
    android:id="@+id/fragmentContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:foreground="?android:windowContentOverlay"
    />

</LinearLayout>

Answer 3

This is how I display the shadow:

<!-- API level 21 and above then the elevation attribute is enough. For some reason it can't be set directly on the include so I wrap it in a FrameLayout -->
<FrameLayout
    android:id="@+id/topwrapper"
    android:background="@color/theme_primary"
    android:elevation="4dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <include layout="@layout/toolbar_actionbar" />
</FrameLayout>

<FrameLayout
    android:layout_below="@id/topwrapper"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <WebView
        android:id="@+id/webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
    <!-- This topshadow is hidden in code for API level 21 and above -->
    <include layout="@layout/topshadow" />
</FrameLayout>

And then the topshadow layout looks like this (adjust the 5dp to get the shadow height you want):

<View xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="5dp"
    android:id="@+id/shadow_prelollipop"
    android:background="@drawable/background_shadow" />

background_shadow.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

    <gradient
        android:startColor="#02444444"
        android:endColor="#33111111"
        android:angle="90"></gradient>
</shape>

toolbar_actionbar.xml

<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:myapp="http://schemas.android.com/apk/res-auto"
    myapp:theme="@style/ActionBarThemeOverlay"
    myapp:popupTheme="@style/ActionBarPopupThemeOverlay"
    android:id="@+id/toolbar_actionbar"
    android:background="@color/theme_primary"
    myapp:titleTextAppearance="@style/ActionBar.TitleText"
    myapp:contentInsetStart="?actionBarInsetStart"
    android:layout_width="match_parent"
    android:layout_height="?actionBarSize" />

Answer 4

actionbar_background.xml

    <item>
        <shape>
            <solid android:color="@color/black" />
            <corners android:radius="2dp" />
            <gradient
                android:startColor="@color/black"
                android:centerColor="@color/black"
                android:endColor="@color/white"
                android:angle="270" />
        </shape>
    </item>

    <item android:bottom="3dp" >
        <shape>

            <solid android:color="#ffffff" />
            <corners android:radius="1dp" />
        </shape>
    </item>
</layer-list>

add to actionbar_style background

<style name="Theme.ActionBar" parent="style/Widget.AppCompat.Light.ActionBar.Solid">
    <item name="background">@drawable/actionbar_background</item>
    <item name="android:elevation">0dp</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:layout_marginBottom">5dp</item>
    <item name="logo">@drawable/ab_logo</item>
    <item name="displayOptions">useLogo|showHome|showTitle|showCustom</item>
</style>

add to Basetheme

  <style name="BaseTheme" parent="Theme.AppCompat.Light">
            <item name="android:homeAsUpIndicator">@drawable/home_back</item>
            <item name="actionBarStyle">@style/TFKBTheme.ActionBar</item>
    </style>