Toolbar's shadow on status bar for Lollipop

问题:

I'm using a template from Android Studio that used AppCompat Toolbar. Unfortunately, the toolbar casts shadow on the status bar so it doesn't look right.I also implement a NavigationDrawer so I can't simply set the color of the status bar.

This is how it looks:

This is how it should be:

activity_main.xml

<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:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">

<include
    layout="@layout/app_bar_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<android.support.design.widget.NavigationView
    android:id="@+id/nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    app:headerLayout="@layout/nav_header_main"
    app:menu="@menu/activity_main_drawer" />

</android.support.v4.widget.DrawerLayout>

app_bar_main.xml

<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="hu.pe.thinhhoang.aaosync.MainActivity">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

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

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

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

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

styles.xml (v21)

<resources>>

<style name="AppTheme.NoActionBar">
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>
    <item name="android:windowDrawsSystemBarBackgrounds">true</item>
    <item name="android:statusBarColor">@android:color/transparent</item>
</style>

</resources>

回答1:

This shadow is part of windowContentOverlay on APIs below LOLLIPOP (on LOLLIPOP it's @null).

When you work with Toolbar widget the toolbar isn't part of window decor anymore so the shadow starts at the top of the window over the toolbar instead of below it (so you want the windowContentOverlay to be @null). Additionally you need to add an extra empty View below the toolbar pre-LOLLIPOP with its background set to a vertical shadow drawable (8dp tall gradient from #20000000 to #00000000 works best). On LOLLIPOP you can set 8dp elevation on the toolbar instead.

回答2:

Put a LinearLayout in like this:

<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"
android:fitsSystemWindows="true"
tools:context=".ui.activities.MainScreenActivity">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

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

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

    <include layout="@layout/content_main_screen" />
</LinearLayout>
</android.support.design.widget.CoordinatorLayout>

回答3:

I tried all the other answers and none worked. What fixed it was adding this to the AppBarLayout:

    app:elevation="0dp"

回答4:

That's because of :

<item name="android:statusBarColor">@android:color/transparent</item>

i guess.

Got it, check this:

http://developer.android.com/training/material/theme.html#StatusBar

To set a custom color for the status bar, use the android:statusBarColor attribute when you extend the material theme. By default, android:statusBarColor inherits the value of android:colorPrimaryDark.

And you've set it to transparent.this is not a good way for doing that since Google put this code for you:

<item name="colorPrimaryDark">@color/colorPrimaryDark</item>

And also, instead of:

<style name="AppTheme.NoActionBar">

Use this and add a parent and check:

<style name="AppTheme.NoActionBar" parent="Theme.AppCompat.Light.NoActionBar">

回答5:

To get the correct behavior, you will need to remove

android:fitsSystemWindows="true"

From android.support.design.widget.CoordinatorLayout

In your styles.xml, color defined in colorPrimaryDarkwill be used for drawing the notification bar.

You will need to have styles.xml in your values-v21 folder with following item in your styles:

 <item name="android:statusBarColor">@android:color/transparent</item>

Hope this helps.