我已经使用首选项创建了一个应用程序设置。 但我注意到，我的 PreferenceActivity 中没有工具栏。 如何将工具栏添加到我的 PreferenceActivity？

我的代码:

我的 pref_xml:

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android">
<ListPreference
    android:key="select_class"
    android:title="@string/select_class"
    android:defaultValue="0"
    android:entries="@array/classy"
    android:entryValues="@array/classy"
    android:dialogTitle="@string/select_class" />
</PreferenceScreen>

我的 PrefActivity.java:

package ***.***.***;

import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;

public class PrefActivity extends PreferenceActivity {
@Override
protected void onCreate(final Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    getFragmentManager().beginTransaction().replace(android.R.id.content, new PrefFragment()).commit();
}

public static class PrefFragment extends PreferenceFragment
{
    @Override
    public void onCreate(final Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.pref);
    }
}
}

P.S Gautam，在您的 .java 代码行中有一个错误:

setSupportActionBar(toolbar); :

     java.lang.RuntimeException: Unable to start activity ComponentInfo{xxx/xxx.PrefActivity}: java.lang.IllegalStateException: This Activity already has an action bar supplied by the window decor. Do not request Window.FEATURE_SUPPORT_ACTION_BAR and set windowActionBar to false in your theme to use a Toolbar instead.
                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2331)
                                                                             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2391)
                                                                             at android.app.ActivityThread.access$800(ActivityThread.java:151)
                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1309)
                                                                             at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                             at android.os.Looper.loop(Looper.java:135)
                                                                             at android.app.ActivityThread.main(ActivityThread.java:5349)
                                                                             at java.lang.reflect.Method.invoke(Native Method)
                                                                             at java.lang.reflect.Method.invoke(Method.java:372)
                                                                             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)
                                                                             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)
                                                                          Caused by: java.lang.IllegalStateException: This Activity already has an action bar supplied by the window decor. Do not request Window.FEATURE_SUPPORT_ACTION_BAR and set windowActionBar to false in your theme to use a Toolbar instead.
                                                                             at android.support.v7.app.AppCompatDelegateImplV7.setSupportActionBar(AppCompatDelegateImplV7.java:198)
                                                                             at android.support.v7.app.AppCompatActivity.setSupportActionBar(AppCompatActivity.java:130)
                                                                             at com.smartfon_apps.timetable_sch32.PrefActivity.onCreate(PrefActivity.java:21)
                                                                             at android.app.Activity.performCreate(Activity.java:6020)
                                                                             at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2284)
                                                                             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2391) 
                                                                             at android.app.ActivityThread.access$800(ActivityThread.java:151) 
                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1309) 
                                                                             at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                             at android.os.Looper.loop(Looper.java:135) 
                                                                             at android.app.ActivityThread.main(ActivityThread.java:5349) 
                                                                             at java.lang.reflect.Method.invoke(Native Method) 
                                                                             at java.lang.reflect.Method.invoke(Method.java:372) 
                                                                             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908) 
                                                                             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703) 

最佳答案

使用扩展 AppCompatActivity 的 Activity ，其中包含从布局文件引用的工具栏，如下所示

public class UserSettingPreference extends AppCompatActivity {

Toolbar toolbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.toolbar);
    toolbar = (Toolbar) findViewById(R.id.toolbar);
    toolbar.setTitle("Settings");
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    toolbar.setNavigationOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

                onBackPressed();

        }
    });
    getFragmentManager().beginTransaction().replace(R.id.fragment_container,
            new UserPreferenceFragment()).commit();
}

}

定义包含工具栏和框架布局的布局以容纳 fragment

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<Toolbar 
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#80000000"
    android:minHeight="?android:attr/actionBarSize"
    app:contentInsetEnd="0dp"
    app:contentInsetLeft="0dp"
    app:contentInsetRight="0dp"
    app:contentInsetStart="0dp"/>


<FrameLayout
    android:id="@+id/fragment_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
  />
</LinearLayout>

然后定义您的 fragment 扩展偏好 fragment ，如下所示 -

public class UserPreferenceFragment extends PreferenceFragment

要引用您的 preference.xml 覆盖 fragment 的 onCreate，如下所示 -

 @Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    addPreferencesFromResource(R.xml.fragment_preference);
}

要引用 preference.xml 中的特定元素，请使用 getPreferenceScreen 方法

switchPreference = (SwitchPreference) getPreferenceScreen().findPreference("floating_widget");

关于java - 如何在PreferenceActivity中添加Toolbar，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39200846/