AppCompat PreferenceActivity 向上按钮不起作用

我正在尝试创建一个扩展 AppCompatPreferenceActivity 并在操作栏中实现向上按钮的活动。视觉上一切看起来都很好，但向上按钮不响应触摸事件。以下是我的java和xml代码：

PrefrencesDisplayActivity.java

package com.example.matthew.testsettings;

import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CoordinatorLayout;
import android.support.v7.widget.Toolbar;
import android.widget.ListView;
import android.widget.RelativeLayout;

import java.util.List;

public class PreferencesDisplayActivity extends AppCompatPreferenceActivity {
    CoordinatorLayout activityRoot;
    AppBarLayout appBarLayout;
    Toolbar toolbar;
    RelativeLayout contentRoot;
    ListView preferencesList;

    @Override
    public void onBuildHeaders(List<Header> target) {
        loadHeadersFromResource(R.xml.preferences, target);
        initialiseUI();
    }

    private void initialiseUI() {
        // Inflate activity layout from xml
        setContentView(R.layout.activity_preferences_display);

        // Get handles to UI elements
        activityRoot = (CoordinatorLayout) findViewById(R.id.prefDisplay_activity_root);
        appBarLayout = (AppBarLayout) findViewById(R.id.prefdisplay_activity_appBarLayout);
        toolbar = (Toolbar) findViewById(R.id.prefDisplay_activity_toolbar);
        contentRoot = (RelativeLayout) findViewById(R.id.prefDisplay_content_root);
        preferencesList = (ListView) findViewById(android.R.id.list);

        // Create and configure action bar
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    }
}

Activity_prefrences_display.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    android:theme="@style/AppTheme.NoActionBar"
    android:id="@+id/prefDisplay_activity_root"
    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="com.example.matthew.testsettings.PreferencesDisplayActivity">

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

        <android.support.v7.widget.Toolbar
            android:id="@+id/prefDisplay_activity_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_preferences_display"/>

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

内容_首选项_显示.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    android:id="@+id/prefDisplay_content_root"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_preferences_display"
    tools:context="com.example.matthew.testsettings.PreferencesDisplayActivity">

    <ListView
        android:id="@id/android:list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"/>
</RelativeLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest
    package="com.example.matthew.testsettings"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

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

            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>

        <activity
            android:name=".PreferencesDisplayActivity"
            android:label="@string/title_activity_preferences_display"
            android:parentActivityName="com.example.matthew.testsettings.MainActivity"
            android:theme="@style/AppTheme.NoActionBar">

            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.example.matthew.testsettings.MainActivity"/>
        </activity>
    </application>
</manifest>

当我打开应用程序并导航到首选项活动时，屏幕看起来应该是这样，但按向上按钮没有任何反应。谁能看到我的错误吗？

你也可以只使用finish()当按下后退按钮时：

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    if (id == android.R.id.home) {
        finish();
        return true;
    }
    return super.onOptionsItemSelected(item);
}