当想要显示对话框时，App force关闭

Question

我一直试图在用户没有启用GPS时使用AlertDialog打开，并使用intent将它们指向Settings.ACIOTN_LOCATION_SOURCE_SETTINGS。

private void buildAlertDialog() 
{ 
    // TODO Auto-generated method stub 
    AlertDialog.Builder builder = new AlertDialog.Builder(getApplicationContext()); 
    builder.setMessage("Gps is disabled, do you want to enable it?"); 
    builder.setCancelable(false); 
    builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() { 

     @Override 
     public void onClick(DialogInterface dialog, int id) 
     { 
      // TODO Auto-generated method stub 
      startActivity(new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS)); 

     } 
    }); 

    builder.setNegativeButton("No", new DialogInterface.OnClickListener() { 

     @Override 
     public void onClick(DialogInterface dialog, int id) { 
      // TODO Auto-generated method stub 
      dialog.cancel(); 
     } 
    }); 
    AlertDialog alert = builder.create(); 
    alert.show(); 
} 

的buildAlertDialog()是当用户输入该活动和GSP未启用它是由这个片段的代码称为称为

mLocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE); 
    if(!mLocManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) 
    { 
     buildAlertDialog(); 
    } 
    mLocListener = new LocListener(); 
    mLocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, mLocListener); 

错误的logcat的输出如下

FATAL EXCEPTION: main 
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.fyp.run_race/com.fyp.run_race.Begin_Run}: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application 
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2781) 
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2797) 
at android.app.ActivityThread.access$2300(ActivityThread.java:135) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2132) 
at android.os.Handler.dispatchMessage(Handler.java:99) 
at android.os.Looper.loop(Looper.java:143) 
at android.app.ActivityThread.main(ActivityThread.java:4914) 
at java.lang.reflect.Method.invokeNative(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:521) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
at dalvik.system.NativeStart.main(Native Method) 
Caused by: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application 
at android.view.ViewRoot.setView(ViewRoot.java:513) 
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:177) 
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91) 
at android.app.Dialog.show(Dialog.java:241) 
at com.fyp.run_race.Begin_Run.buildAlertDialog(Begin_Run.java:133) 
at com.fyp.run_race.Begin_Run.onCreate(Begin_Run.java:82) 
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1065) 
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2745) 
... 11 more 

我认为这可能是新的活动没有注册的应用程序的Android清单文件

Answer 1

有可能与getApplicationContext()线路有问题，检查this thread

你应该传递一个Activity参考builderAlertDialog()这将是this如果该方法是从Activity类调​​用。