AlertDialog.show()上的RuntimeException

Question

当我想在活动开始时显示alertdialog时,我不断收到异常.我想不通为什么？我真的很感激解释.

代码:

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.main);

    if (!isInternetConnectionAvailable()) {
        AlertDialog alert = new AlertDialog.Builder(getApplicationContext()).create();
        alert.setMessage("TEST DIALOG!!!");
        alert.show();
    }
...

03-19 16:04:33.933:ERROR/AndroidRuntime(15145):FATAL EXCEPTION:main 03-19 16:04:33.933:ERROR/AndroidRuntime(15145):java.lang.RuntimeException:无法启动活动ComponentInfo {de. droidgroup.THMInfo/de.droidgroup.THMInfo.Activities.StartActivity}:android.view.WindowManager $ BadTokenException:无法添加窗口 - 令牌null不适用于应用程序03-19 16:04:33.933:ERROR/AndroidRuntime(15145 ):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)03-19 16:04:33.933:ERROR/AndroidRuntime(15145):在android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)03- 19 16:04:33.933:ERROR/AndroidRuntime(15145):在android.app.ActivityThread.access $ 2300(ActivityThread.java:125)03-19 16:04:33.933:ERROR/AndroidRuntime(15145):at android.app .ActivityThread $ H.handleMessage(ActivityThread.java:2033)03-19 16:04:33.933:ERROR/AndroidRuntime(15145):at android.os.Handler.dispatchMessage(Handler.java:99)03-19 16:04 :33.933:ERROR/AndroidRuntime(15145):在android.os.Looper.loop(Looper.java:123)03-19 16:04:33.933:ERROR/AndroidRuntime(15145):在android.app.ActivityThread.main(ActivityThread.java:4627)03 -19 16:04:33.933:ERROR/AndroidRuntime(15145):at java.lang.reflect.Method.invokeNative(Native Method)03-19 16:04:33.933:ERROR/AndroidRuntime(15145):at java.lang. reflect.Method.invoke(Method.java:521)03-19 16:04:33.933:ERROR/AndroidRuntime(15145):at com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:858)03 -19 16:04:33.933:ERROR/AndroidRuntime(15145):at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)03-19 16:04:33.933:ERROR/AndroidRuntime(15145): at dalvik.system.NativeStart.main(Native Method)03-19 16:04:33.933:ERROR/AndroidRuntime(15145):引起:android.view.WindowManager $ BadTokenException:无法添加窗口 - 令牌null不适用于应用03-19 16:04:33.933:ERROR/AndroidRuntime(15145):在android.view.ViewRoot.setView(ViewRoot.java:509)03-19 16:04:33.933:ER ROR/AndroidRuntime(15145):在android.view.WindowManagerImpl.addView(WindowManagerImpl.java:177)03-19 16:04:33.933:ERROR/AndroidRuntime(15145):在android.view.WindowManagerImpl.addView(WindowManagerImpl.java) :91)03-19 16:04:33.933:ERROR/AndroidRuntime(15145):在android.app.Dialog.show(Dialog.java:241)03-19 16:04:33.933:ERROR/AndroidRuntime(15145): at de.droidgroup.THMInfo.Activities.StartActivity.onCreate(StartActivity.java:82)03-19 16:04:33.933:ERROR/AndroidRuntime(15145):at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049) 03-19 16:04:33.933:ERROR/AndroidRuntime(15145):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)03-19 16:04:33.933:ERROR/AndroidRuntime(15145):...还有11个

Answer 1

用this而不是getApplicationContext().更多信息在这里.