我正在尝试使用透明的工具栏渐变,但是没有任何效果.这是我的代码.

activity_main.xml(已更新)

    <android.support.design.widget.CoordinatorLayout 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"
    tools:context="com.amrat.MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/gradient"
        android:theme="@style/AppTheme.AppBarOverlay"
        app:elevation="0dp">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="@drawable/gradient"
            android:layout_alignParentBottom="true"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_main" />

</android.support.design.widget.CoordinatorLayout>

渐变文件

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <gradient
        android:angle="270"
        android:endColor="#00ffffff"
        android:startColor="#ffffff"
        android:type="linear" />
</shape>

尝试这样做：

但是得到这个：

如果有人知道该怎么做,请帮助我.

更新

AndroidManifest.xml

<activity
    android:name=".activity.MainActivity"
    android:theme="@style/AppTheme.Transparent.NoActionBar" />

style.xml
    

    <item name="colorPrimary">@android:color/transparent</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>

    <item name="colorControlNormal">@color/light_grey_1</item>
    <item name="colorControlActivated">@color/orange_1</item>
    <item name="colorControlHighlight">@color/light_grey_2</item>
</style>

解决方法:

直接使用@android：color / transparent.跟随这个-
工具栏布局-

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:background="@drawable/background_toolbar_transparent" />

background_toolbar_transparent.xml

<?xml version="1.0" encoding="utf-8"?>

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

    <gradient
        android:angle="270"
        android:endColor="@android:color/transparent"
        android:startColor="@color/black_alpha"/>
</shape>

使用alphaon colors.xml添加颜色-

<color name="black_alpha">#66000000</color>