addpreferencesfromresource导致FC:错误膨胀类CheckboxPreference

Question

每次我切换到偏好活动，我得到一个运行时错误，fc我的应用程序。我试图学习Android编程，我设法解决了我遇到的问题，但经过大量的时间搜索帮助，我无法理解我做错了什么。

这是Settings.java的代码:

package com.wisp.sudokuapp;
import android.os.Bundle;
import android.preference.PreferenceActivity;
public class Settings extends PreferenceActivity {
    @SuppressWarnings("deprecation")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.settings);
    }
}

我settings.xml

:

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
    xmlns:android="http://schemas.android.com/apk/res/android" >
    <CheckboxPreference
       android:key="hints"
       android:title="@string/settings_hints_title"
       android:summary="@string/settings_hints_summary"
       android:defaultValue="true" />
    <CheckboxPreference
       android:key="music"
       android:title="@string/settings_music_title"
       android:summary="@string/settings_music_summary"
       android:defaultValue="true" />
</PreferenceScreen>

我的清单:

(...)
        <activity android:name="com.wisp.sudokuapp.Settings"
            android:label="@string/settings_title">
        </activity>
(...)

和Logcat:

03-25 17:22:22.637: W/dalvikvm(440): threadid=1: thread exiting with uncaught exception (group=0x40015560)
03-25 17:22:22.687: E/AndroidRuntime(440): FATAL EXCEPTION: main
03-25 17:22:22.687: E/AndroidRuntime(440): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.wisp.sudokuapp/com.wisp.sudokuapp.Settings}: android.view.InflateException: Binary XML file line #5: Error inflating class CheckboxPreference
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.app.ActivityThread.access$1500(ActivityThread.java:117)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.os.Handler.dispatchMessage(Handler.java:99)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.os.Looper.loop(Looper.java:123)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.app.ActivityThread.main(ActivityThread.java:3683)
03-25 17:22:22.687: E/AndroidRuntime(440):  at java.lang.reflect.Method.invokeNative(Native Method)
03-25 17:22:22.687: E/AndroidRuntime(440):  at java.lang.reflect.Method.invoke(Method.java:507)
03-25 17:22:22.687: E/AndroidRuntime(440):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
03-25 17:22:22.687: E/AndroidRuntime(440):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
03-25 17:22:22.687: E/AndroidRuntime(440):  at dalvik.system.NativeStart.main(Native Method)
03-25 17:22:22.687: E/AndroidRuntime(440): Caused by: android.view.InflateException: Binary XML file line #5: Error inflating class CheckboxPreference
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.preference.GenericInflater.createItemFromTag(GenericInflater.java:441)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.preference.GenericInflater.rInflate(GenericInflater.java:481)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.preference.GenericInflater.inflate(GenericInflater.java:326)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.preference.GenericInflater.inflate(GenericInflater.java:263)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.preference.PreferenceManager.inflateFromResource(PreferenceManager.java:251)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.preference.PreferenceActivity.addPreferencesFromResource(PreferenceActivity.java:262)
03-25 17:22:22.687: E/AndroidRuntime(440):  at com.wisp.sudokuapp.Settings.onCreate(Settings.java:11)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
03-25 17:22:22.687: E/AndroidRuntime(440):  ... 11 more
03-25 17:22:22.687: E/AndroidRuntime(440): Caused by: java.lang.ClassNotFoundException: android.preference.CheckboxPreference in loader dalvik.system.PathClassLoader[/data/app/com.wisp.sudokuapp-1.apk]
03-25 17:22:22.687: E/AndroidRuntime(440):  at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
03-25 17:22:22.687: E/AndroidRuntime(440):  at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
03-25 17:22:22.687: E/AndroidRuntime(440):  at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.preference.GenericInflater.createItem(GenericInflater.java:375)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.preference.GenericInflater.onCreateItem(GenericInflater.java:417)
03-25 17:22:22.687: E/AndroidRuntime(440):  at android.preference.GenericInflater.createItemFromTag(GenericInflater.java:428)
03-25 17:22:22.687: E/AndroidRuntime(440):  ... 19 more

我知道这个方法已经过时了，但我希望它能在2.3.x上工作。为了学习android开发，我正在读一本书，在书中似乎是可行的。我发现注释掉addPreferencesFromResource行可以防止应用程序崩溃，但显然不会加载任何UI。

我真的很感谢你的帮助。

抱歉我的英语不好

Answer 1

问题是xml文件中的一个错别字。将CheckboxPreference改为CheckboxPreference

Answer 2

你有一个拼写错误。两个,事实上。试一试:

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
    xmlns:android="http://schemas.android.com/apk/res/android" >
    <CheckBoxPreference
       android:key="hints"
       android:title="@string/settings_hints_title"
       android:summary="@string/settings_hints_summary"
       android:defaultValue="true" />
    <CheckBoxPreference
       android:key="music"
       android:title="@string/settings_music_title"
       android:summary="@string/settings_music_summary"
       android:defaultValue="true" />
</PreferenceScreen>

Android XML是区分大小写的，所以CheckboxPreference和CheckBoxPreference是不同的，不存在的东西。