我在 preferences.xml 中有这个

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

    <CheckBoxPreference
        android:key="displayNotification"
        android:title="Display notification"
        />

    <ListPreference
        android:entries="@array/languages"
        android:key="language"
        />
</PreferenceScreen>

PreferencesActivity.java，使用这个xml的类

public class PreferencesActivity extends PreferenceActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        setContentView(R.xml.preferences);
    }
}

我在 list 中这样声明

<activity android:name="com.tellthetime.PreferencesActivity" />

当我开始这个 Activity 时，我得到一个类未找到的异常，我不明白这是什么。

05-17 00:35:13.633: ERROR/AndroidRuntime(212): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tellthetime/com.tellthetime.PreferencesActivity}: android.view.InflateException: Binary XML file line #2: Error inflating class PreferenceScreen
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.app.ActivityThread.access$2200(ActivityThread.java:119)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.os.Looper.loop(Looper.java:123)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.app.ActivityThread.main(ActivityThread.java:4363)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at java.lang.reflect.Method.invokeNative(Native Method)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at java.lang.reflect.Method.invoke(Method.java:521)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at dalvik.system.NativeStart.main(Native Method)
05-17 00:35:13.633: ERROR/AndroidRuntime(212): Caused by: android.view.InflateException: Binary XML file line #2: Error inflating class PreferenceScreen
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:576)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.view.LayoutInflater.inflate(LayoutInflater.java:385)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:198)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.app.Activity.setContentView(Activity.java:1622)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at com.tellthetime.PreferencesActivity.onCreate(PreferencesActivity.java:13)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     ... 11 more
05-17 00:35:13.633: ERROR/AndroidRuntime(212): Caused by: java.lang.ClassNotFoundException: android.view.PreferenceScreen in loader dalvik.system.PathClassLoader@44c067e8
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at java.lang.ClassLoader.loadClass(ClassLoader.java:573)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at java.lang.ClassLoader.loadClass(ClassLoader.java:532)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.view.LayoutInflater.createView(LayoutInflater.java:466)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.view.LayoutInflater.onCreateView(LayoutInflater.java:544)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:563)
05-17 00:35:13.633: ERROR/AndroidRuntime(212):     ... 19 more

这已经被问过here但没有人回答。正如 Heiko Rupp 在那个帖子中指出的那样，android 正在寻找 android.view 包中的类，但该类在 android.preferences 中，这真的让我迷路了.

最佳答案

您感到困惑，您正试图将首选项 定义设置为布局 定义。首先为 Activity 设置布局，然后绑定(bind)您的首选项 XML:

  ...
  setContentView(R.layout.layout);
  addPreferencesFromResource(R.xml.preferences);
  ...

关于java - 找不到 PreferenceScreen 类，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/6025349/