如何在Android支持库v7 rev23中使用首选项？

Question

在我使用支持库v7的应用程序中,我想添加一个首选项屏幕.由于Google完全没有提供有关该主题的文档,因此我查找了Stack Overflow上其他地方发现的帖子.

所以这是我的项目:

activity_preferences.xml

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

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

    <fragment
        android:name=".FragmentPreferences"
        name=".FragmentPreferences"
        android:tag=".FragmentPreferences"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

ActivityPreferences.java

package com.example.testandroidsupportv7;

import com.example.testandroidsupportv7.R;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

public class ActivityPreferences extends AppCompatActivity
{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_preferences);
    }

}

FragmentPreferences.java

package com.example.testandroidsupportv7;

import com.example.testandroidsupportv7.R;
import android.os.Bundle;
import android.support.v7.preference.PreferenceFragmentCompat;

public class FragmentPreferences extends PreferenceFragmentCompat
{

    @Override
    public void onCreatePreferences(Bundle bundle, String s) {
        addPreferencesFromResource(R.xml.preferences);
    }

}

AndroidManifest.xml中

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

XML /的preferences.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.preference.PreferenceScreen
    xmlns:android="http://schemas.android.com/apk/res/android" >

    <android.support.v7.preference.PreferenceCategory
        android:title="Splošne nastavitve" >

        <android.support.v7.preference.CheckBoxPreference
            android:key="PREFERENCE_KEY_CHECK_BOX"
            android:defaultValue="false"
            android:summaryOff="Value is OFF."
            android:summaryOn="Value is ON."
            android:title="Check box preference" />

    </android.support.v7.preference.PreferenceCategory>

</android.support.v7.preference.PreferenceScreen>

如果我尝试启动此首选项活动,我会得到一个例外.

logcat的

FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.testandroidsupportv7/com.example.testandroidsupportv7.ActivityPreferences}: android.view.InflateException: Binary XML file line #11: Error inflating class fragment
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
    at android.app.ActivityThread.access$1500(ActivityThread.java:117)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:130)
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.testandroidsupportv7/com.example.testandroidsupportv7.ActivityPreferences}: android.view.InflateException: Binary XML file line #11: Error inflating class fragment
    at android.app.ActivityThread.main(ActivityThread.java:3691)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:507)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: android.view.InflateException: Binary XML file line #11: Error inflating class fragment
FATAL EXCEPTION: main
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:581)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:623)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:408)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
    at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:257)
    at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109)
    at com.example.testandroidsupportv7.ActivityPreferences.onCreate(ActivityPreferences.java:13)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615)
    ... 11 more
Caused by: java.lang.ClassNotFoundException: android.view.fragment in loader dalvik.system.PathClassLoader[/data/app/com.example.testandroidsupportv7-2.apk]
    at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
    at android.view.LayoutInflater.createView(LayoutInflater.java:471)
    at android.view.LayoutInflater.onCreateView(LayoutInflater.java:549)
    at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:568)
    ... 20 more
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651)

这段代码有什么问题？这应该工作.给出的例外是令人费解的,并没有提供任何线索.Google没有提供任何文档,也没有工作示例.我发现可疑的是这条线:

引起:java.lang.ClassNotFoundException:loader dalvik.system.PathClassLoader中的android.view.fragment [/data/app/com.example.testandroidsupportv7-2.apk]

如何摆脱这种异常？

UPDATE

我在android 2.3.5设备上运行.我添加了preference.xml

Answer 1

你的logcat提示错误:XML file line #11: Error inflating class fragment- 似乎name=".FragmentPreferences"你可能想要的可疑行android:name=".FragmentPreferences".既然你已经有了,那就删除错误的行:)

<fragment
    android:name=".FragmentPreferences"
    android:tag=".FragmentPreferences"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

更新:如果这不起作用,那么另一个明显的错误就是android:name值.它应该是:

android:name="com.example.testandroidsupportv7.FragmentPreferences"

或者你的FragmentPreferences类的实际路径.

我甚至在我的最后建立了你的项目,花了不到5分钟的时间来创建,测试和确认错误; 我得到了与你完全相同的错误,当我修复android:name它时构建得很好.截图:

我希望你能为你的行为向所有人道歉...这不是如何从SO上获得人们的帮助.

更新2:来自我的构建的部分logcat,错误的android:name值:

11-07 14:00:24.742 26456-26456/com.example.testandroidsupportv7 E/AndroidRuntime: FATAL EXCEPTION: main
11-07 14:00:24.742 26456-26456/com.example.testandroidsupportv7 E/AndroidRuntime: Process: com.example.testandroidsupportv7, PID: 26456
11-07 14:00:24.742 26456-26456/com.example.testandroidsupportv7 E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.testandroidsupportv7/com.example.testandroidsupportv7.ActivityPreferences}: android.view.InflateException: Binary XML file line #8: Error inflating class fragment
11-07 14:00:24.742 26456-26456/com.example.testandroidsupportv7 E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2345)
11-07 14:00:24.742 26456-26456/com.example.testandroidsupportv7 E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2405)
11-07 14:00:24.742 26456-26456/com.example.testandroidsupportv7 E/AndroidRuntime:     at android.app.ActivityThread.access$800(ActivityThread.java:155)
11-07 14:00:24.742 26456-26456/com.example.testandroidsupportv7 E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1323)
...
11-07 14:00:24.742 26456-26456/com.example.testandroidsupportv7 E/AndroidRuntime:   Suppressed: java.lang.ClassNotFoundException: Invalid name: .FragmentPreferences

依赖关系:

compile 'com.android.support:support-v4:23.1.0'
compile 'com.android.support:appcompat-v7:23.1.0'
compile 'com.android.support:preference-v7:23.1.0'
compile 'com.android.support:design:23.1.0'

请不要让我现在找一个2.3.5设备来测试你.