android - 如何在CollapsingToolbarLayout中将扩展标题居中

展开布局时，我想将工具栏标题居中，这是我的代码:

<?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:id="@+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<android.support.design.widget.AppBarLayout
    android:layout_height="256dp"
    android:layout_width="match_parent"
    app:contentScrim="?attr/colorPrimary"
    android:fitsSystemWindows="true"
    app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"
        android:fitsSystemWindows="true"
        app:contentScrim="?attr/colorPrimary"
        app:expandedTitleMarginStart="48dp"
        app:expandedTitleMarginBottom="60dp">
        <ImageView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scaleType="centerCrop"
            android:fitsSystemWindows="true"
            app:layout_collapseMode="parallax"/>
        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_height="?attr/actionBarSize"
            android:layout_width="match_parent"
            app:layout_collapseMode="pin"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
    </android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.widget.NestedScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">
</android.support.v4.widget.NestedScrollView>

最佳答案

尝试将 ExpandedTitleGravity 作为应用程序属性添加到 CollapsingToolbarLayout 中:

app:expandedTitleGravity="center_horizontal"

例子:

<android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        app:contentScrim="@color/colorPrimary"
        app:expandedTitleGravity="center_horizontal"
        app:layout_scrollFlags="scroll|exitUntilCollapsed">