actionbar默认图标更改

    <!-- Application theme. -->
    <style name="AppTheme" parent="AppBaseTheme">

        <!-- colorPrimary is used for the default action bar background -->
        <item name="colorPrimary">@color/actionbar_backgroud</item>

        <!-- colorPrimaryDark is used for the status bar -->
        <item name="colorPrimaryDark">@color/actionbar_backgroud_dark</item>
        <!-- theme UI controls like checkboxes and text fields -->
        <!-- <item name="android:colorAccent">@color/actionbar_backgroud</item> -->
        <item name="android:actionModeBackground">@color/actionbar_backgroud</item>
        <!--更改home返回按钮的图标-->
        <item name="android:homeAsUpIndicator">@drawable/ic_actionbar_home</item> 
        <!--溢出菜单样式-->
        <item name="android:actionOverflowButtonStyle">@style/OverFlowButtonStyle</item> 
        <item name="android:actionModeCloseDrawable">@drawable/ic_actionbar_home</item>
        <item name="android:windowContentOverlay">@null</item>
    </style>

    <!--更改溢出菜单的图标-->
    <style name="OverFlowButtonStyle" parent="Widget.AppCompat.Light.ActionButton.Overflow">
        <item name="android:src">@drawable/ic_actionbar_overflow</item>
    </style>