Android: "BadTokenException: Unable to add window; is your activity running?"在 PreferenceActivity 中显示对话框

Question

我想寻求帮助:在我的应用程序中，我只有一个 Activity ，即 PreferenceActivity(不需要其他 Activity ，它只是一个简单的后台同步应用程序，所以PrefsActivity 是 Main/Launcher)。在用户设置首选项后，检查 checkBoxPreference，然后启动(或停止)服务。开始时，会显示一个对话框。 但问题是:如果用户按下(离开 Activity )，再次启动它，然后尝试检查 checkBoxPref。，prefsactivity 崩溃。对话框不显示。我不知道为什么，以及如何解决它。

这段代码与那部分完全相同，是什么给了我问题:

PrefsActivity.java:

   package is.it.works;

   // imports .....

   public class PrefsActivity extends PreferenceActivity implements OnSharedPreferenceChangeListener {
SharedPreferences prefs;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    addPreferencesFromResource(R.xml.prefs);
    prefs = PreferenceManager.getDefaultSharedPreferences(this);
    prefs.registerOnSharedPreferenceChangeListener(this);
}// onCreate

@Override
public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {
    if (key.equals("checkTest")) {
        showDialog(1);
    }
    if (key.equals("cancel")) {
        dismissDialog(1);
    }
}// onSPC

@Override
protected Dialog onCreateDialog(int id) {
    switch (id) {
    case 1: {
        ProgressDialog dialog = new ProgressDialog(this);
        dialog.setMessage("press back twice, start the app again, and click checkbox...");
        dialog.setIndeterminate(true);
        dialog.setCancelable(true);
        dialog.setOnCancelListener(new OnCancelListener() {

            @Override
            public void onCancel(DialogInterface dialog) {
                prefs.edit().putBoolean("cancel", false).commit();
            }
        });
        return dialog;
    }// case
    }// switch
    return null;
}// onCreateDialog
}// PrefsActivity

prefs.xml:

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

    <CheckBoxPreference android:key="checkTest" android:title="test" />

</PreferenceScreen>

和 list :

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="is.it.works" android:versionCode="1" android:versionName="1.0">
<uses-sdk android:minSdkVersion="4" />

<application android:icon="@drawable/icon" android:label="@string/app_name">
    <activity android:name=".PrefsActivity" android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

</application>
</manifest>

LogCat 错误:

09-14 10:34:34.472: ERROR/AndroidRuntime(281): Uncaught handler: thread main exiting due to uncaught exception
09-14 10:34:34.502: ERROR/AndroidRuntime(281): android.view.WindowManager$BadTokenException: Unable to add window -- token android.os.BinderProxy@43756de8 is not valid; is your activity running?
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.view.ViewRoot.setView(ViewRoot.java:456)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:177)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.view.Window$LocalWindowManager.addView(Window.java:409)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.app.Dialog.show(Dialog.java:238)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.app.Activity.showDialog(Activity.java:2413)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at is.it.works.PrefsActivity.onSharedPreferenceChanged(PrefsActivity.java:27)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.app.ApplicationContext$SharedPreferencesImpl$EditorImpl.commit(ApplicationContext.java:2727)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.preference.Preference.tryCommit(Preference.java:1199)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.preference.Preference.persistBoolean(Preference.java:1404)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.preference.CheckBoxPreference.setChecked(CheckBoxPreference.java:155)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.preference.CheckBoxPreference.onClick(CheckBoxPreference.java:143)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.preference.Preference.performClick(Preference.java:811)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.preference.PreferenceScreen.onItemClick(PreferenceScreen.java:190)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.widget.AdapterView.performItemClick(AdapterView.java:284)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.widget.ListView.performItemClick(ListView.java:3246)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.widget.AbsListView$PerformClick.run(AbsListView.java:1635)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.os.Handler.handleCallback(Handler.java:587)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.os.Handler.dispatchMessage(Handler.java:92)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.os.Looper.loop(Looper.java:123)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at android.app.ActivityThread.main(ActivityThread.java:4203)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at java.lang.reflect.Method.invokeNative(Native Method)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at java.lang.reflect.Method.invoke(Method.java:521)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
09-14 10:34:34.502: ERROR/AndroidRuntime(281):     at dalvik.system.NativeStart.main(Native Method)
09-14 10:34:34.522: INFO/Process(52): Sending signal. PID: 281 SIG: 3
09-14 10:34:34.532: INFO/dalvikvm(281): threadid=7: reacting to signal 3
09-14 10:34:34.592: INFO/dalvikvm(281): Wrote stack trace to '/data/anr/traces.txt'
09-14 10:34:38.533: DEBUG/dalvikvm(107): GC freed 437 objects / 21560 bytes in 136ms
09-14 10:34:39.183: INFO/global(175): Default buffer size used in BufferedReader constructor. It would be better to be explicit if an 8k-char buffer is required.
09-14 10:34:44.632: INFO/global(175): Default buffer size used in BufferedReader constructor. It would be better to be explicit if an 8k-char buffer is required.
09-14 10:34:47.412: INFO/Process(281): Sending signal. PID: 281 SIG: 9
09-14 10:34:47.472: INFO/ActivityManager(52): Process is.it.works (pid 281) has died.
09-14 10:34:47.492: INFO/WindowManager(52): WIN DEATH: Window{4394f638 is.it.works/is.it.works.PrefsActivity paused=false} 

在google了很多之后，我认为错误的部分是ProgressDialog dialog = new ProgressDialog(this);。导致 this 更改。但是将其更改为 getApplicationContext() 或 PrefsActivity.this 并没有帮助，问题仍然存在。 请告诉我为什么会发生这种情况，以及可能的解决方案!谢谢你! 我被卡住了，现在我不知道......

Answer 1

我遇到了一个非常相似的问题(这让我来到了这里)并找到了一个非常简单的解决方法。虽然我的代码不同，但它应该很容易适应。这是我的解决方法:

public void showBox() {
    mActive = true;
    if (! ((Activity) mContext).isFinishing()) {
        mDialogBox.show();
    }
} 

因此，在问题的示例代码中，修复应该是(猜测):

@Override
public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {
    if (key.equals("checkTest")) {
        if (! this.isFinishing()) {
            showDialog(1);
        }
    }
    if (key.equals("cancel")) {
        dismissDialog(1);
    }
}// onSPC