无法添加窗口 token android.os.BinderProxy 无效；您的活动正在运行吗

我try 通过Facebook API连接到Facebook，我遵循以下示例:https://github.com/facebook/facebook-android-sdk/tree/master/examples/simple

一切正常，但是当我try 编辑一些代码时，我的意思是希望在登录成功后显示对话框POST消息，如下所示:

public void onAuthSucceed() {
        mText.setText("You have logged in! ");   
        //This is the code to call the post message dialog.                     
        mFacebook.dialog(Example.this, "feed",new SampleDialogListener());   
    }

我在logcat中收到此错误:

03-02 13:32:08.629: E/AndroidRuntime(14991): android.view.WindowManager$BadTokenException: Unable to add window -- token android.os.BinderProxy@405180f8 is not valid; is your activity running?
03-02 13:32:08.629: E/AndroidRuntime(14991):    at android.view.ViewRoot.setView(ViewRoot.java:532)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:177)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at android.view.Window$LocalWindowManager.addView(Window.java:424)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at android.app.Dialog.show(Dialog.java:241)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at com.facebook.android.Facebook.dialog(Facebook.java:780)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at com.facebook.android.Facebook.dialog(Facebook.java:737)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at com.facebook.android.Example$SampleAuthListener.onAuthSucceed(Example.java:113)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at com.facebook.android.SessionEvents.onLoginSuccess(SessionEvents.java:78)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at com.facebook.android.Example$LoginDialogListener.onComplete(Example.java:88)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at com.facebook.android.Facebook$1.onComplete(Facebook.java:320)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at com.facebook.android.FbDialog$FbWebViewClient.shouldOverrideUrlLoading(FbDialog.java:144)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at android.webkit.CallbackProxy.uiOverrideUrlLoading(CallbackProxy.java:218)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at android.webkit.CallbackProxy.handleMessage(CallbackProxy.java:337)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at android.os.Handler.dispatchMessage(Handler.java:99)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at android.os.Looper.loop(Looper.java:130)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at android.app.ActivityThread.main(ActivityThread.java:3687)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at java.lang.reflect.Method.invokeNative(Native Method)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at java.lang.reflect.Method.invoke(Method.java:507)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
03-02 13:32:08.629: E/AndroidRuntime(14991):    at dalvik.system.NativeStart.main(Native Method)

有什么 idea 吗？