ListPreference 标签导致我的应用程序崩溃

Question

我尝试了来自 Java Code Geek 的示例代码 Android Settings Example。

当我点击设置浮动操作栏时遇到问题：应用程序崩溃是由于：

FATAL EXCEPTION: main
Process: com.sano.tamer.androidsettings, PID: 32035
java.lang.RuntimeException: Unable to start activity
ComponentInfo{com.sano.tamer.androidsettings/com.sano.tamer.androidsettings.SettingsActivity}: android.view.InflateException: Binary XML file line #14: Error inflating class java.lang.reflect.Constructor

当我评论 ListPreference 标签时，它起作用了，并打开了首选项 activity，我复制并粘贴了首选项文件，这是什么问题？我正在使用 Android 工作室 2.1.2

谢谢

我的设备是 Asus Fonepad 7 FE375CG，运行 Kitkat

这里是完整的错误日志：

07-23 07:06:28.629 5034-5034/com.sano.tamer.androidsettings E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.sano.tamer.androidsettings, PID: 5034
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.sano.tamer.androidsettings/com.sano.tamer.androidsettings.SettingsActivity}: android.view.InflateException: Binary XML file line #14: Error inflating class java.lang.reflect.Constructor
  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2318)
  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2396)
  at android.app.ActivityThread.access0(ActivityThread.java:139)
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1293)
  at android.os.Handler.dispatchMessage(Handler.java:102)
  at android.os.Looper.loop(Looper.java:149)
  at android.app.ActivityThread.main(ActivityThread.java:5252)
  at java.lang.reflect.Method.invokeNative(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:515)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:610)
  at dalvik.system.NativeStart.main(Native Method)
Caused by: android.view.InflateException: Binary XML file line #14: Error inflating class java.lang.reflect.Constructor
  at android.preference.GenericInflater.createItem(GenericInflater.java:397)
  at android.preference.GenericInflater.onCreateItem(GenericInflater.java:417)
  at android.preference.GenericInflater.createItemFromTag(GenericInflater.java:428)
  at android.preference.GenericInflater.rInflate(GenericInflater.java:481)
  at android.preference.GenericInflater.rInflate(GenericInflater.java:493)
  at android.preference.GenericInflater.inflate(GenericInflater.java:326)
  at android.preference.GenericInflater.inflate(GenericInflater.java:263)
  at android.preference.PreferenceManager.inflateFromResource(PreferenceManager.java:272)
  at android.preference.PreferenceActivity.addPreferencesFromResource(PreferenceActivity.java:1472)
  at com.sano.tamer.androidsettings.SettingsActivity.onCreate(SettingsActivity.java:11)
  at android.app.Activity.performCreate(Activity.java:5403)
  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2270)
  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2396) 
  at android.app.ActivityThread.access0(ActivityThread.java:139) 
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1293) 
  at android.os.Handler.dispatchMessage(Handler.java:102) 
  at android.os.Looper.loop(Looper.java:149) 
  at android.app.ActivityThread.main(ActivityThread.java:5252) 
  at java.lang.reflect.Method.invokeNative(Native Method) 
  at java.lang.reflect.Method.invoke(Method.java:515) 
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794) 
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:610) 
  at dalvik.system.NativeStart.main(Native Method) 
Caused by: java.lang.reflect.InvocationTargetException
  at java.lang.reflect.Constructor.constructNative(Native Method)
  at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
  at android.preference.GenericInflater.createItem(GenericInflater.java:383)
  at android.preference.GenericInflater.onCreateItem(GenericInflater.java:417) 
  at android.preference.GenericInflater.createItemFromTag(GenericInflater.java:428) 
  at android.preference.GenericInflater.rInflate(GenericInflater.java:481) 
  at android.preference.GenericInflater.rInflate(GenericInflater.java:493) 
  at android.preference.GenericInflater.inflate(GenericInflater.java:326) 
  at android.preference.GenericInflater.inflate(GenericInflater.java:263) 
  at android.preference.PreferenceManager.inflateFromResource(PreferenceManager.java:272) 
  at android.preference.PreferenceActivity.addPreferencesFromResource(PreferenceActivity.java:1472) 
  at com.sano.tamer.androidsettings.SettingsActivity.onCreate(SettingsActivity.java:11) 
  at android.app.Activity.performCreate(Activity.java:5403) 
  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2270) 
  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2396) 
  at android.app.ActivityThread.access0(ActivityThread.java:139) 
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1293) 
  at android.os.Handler.dispatchMessage(Handler.java:102) 
  at android.os.Looper.loop(Looper.java:149) 
  at android.app.ActivityThread.main(ActivityThread.java:5252) 
  at java.lang.reflect.Method.invokeNative(Native Method) 
  at java.lang.reflect.Method.invoke(Method.java:515) 
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794) 
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:610) 
  at dalvik.system.NativeStart.main(Native Method) 
Caused by: java.lang.NullPointerException
  at android.content.res.AssetManager.getResourceTextArray(AssetManager.java:215)
  at android.content.res.Resources.getTextArray(Resources.java:454)
  at android.content.res.TypedArray.getTextArray(TypedArray.java:629)
  at android.preference.ListPreference.<init>(ListPreference.java:51)
  at java.lang.reflect.Constructor.constructNative(Native Method) 
  at java.lang.reflect.Constructor.newInstance(Constructor.java:423) 
  at android.preference.GenericInflater.createItem(GenericInflater.java:383) 
  at android.preference.GenericInflater.onCreateItem(GenericInflater.java:417) 
  at android.preference.GenericInflater.createItemFromTag(GenericInflater.java:428) 
  at android.preference.GenericInflater.rInflate(GenericInflater.java:481) 
  at android.preference.GenericInflater.rInflate(GenericInflater.java:493) 
  at android.preference.GenericInflater.inflate(GenericInflater.java:326) 
  at android.preference.GenericInflater.inflate(GenericInflater.java:263) 
  at android.preference.PreferenceManager.inflateFromResource(PreferenceManager.java:272) 
  at android.preference.PreferenceActivity.addPreferencesFromResource(PreferenceActivity.java:1472) 
  at com.sano.tamer.androidsettings.SettingsActivity.onCreate(SettingsActivity.java:11) 
  at android.app.Activity.performCreate(Activity.java:5403) 
  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2270) 
  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2396) 
  at android.app.ActivityThread.access0(ActivityThread.java:139) 
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1293) 
  at android.os.Handler.dispatchMessage(Handler.java:102) 
  at android.os.Looper.loop(Looper.java:149) 
  at android.app.ActivityThread.main(ActivityThread.java:5252) 
  at java.lang.reflect.Method.invokeNative(Native Method) 
  at java.lang.reflect.Method.invoke(Method.java:515) 
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794) 
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:610) 
  at dalvik.system.NativeStart.main(Native Method)

Answer 1

这里实际上发生了错误：

Caused by: java.lang.NullPointerException
  at android.content.res.AssetManager.getResourceTextArray(AssetManager.java:215)
  at android.content.res.Resources.getTextArray(Resources.java:454)
  at android.content.res.TypedArray.getTextArray(TypedArray.java:629)
  at android.preference.ListPreference.<init>(ListPreference.java:51)

因此，在读取 TextArray 时似乎是一个空指针。

查看布局 XML，我可以看到您的 ListPreference 使用了两个数组：

<ListPreference
    ...
    android:entries="@array/entries_text"
    android:entryValues="@array/entries_values" 
    ... />

因此，请仔细检查您的文件 res/values/string.xml 并确认您已创建两个数组：entries_text 和 entries_values

<string-array name="entries_text">
    <item>entries 1</item>
    <item>entries 2</item>
    <item>entries 3</item>
</string-array>

<string-array name="entries_values">
    <item>1</item>
    <item>2</item>
    <item>3</item>
</string-array>

ListPreference 标签导致我的应用程序崩溃

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