Android 1.6: “android.view.WindowManager$BadTokenException: Unable to add window ― token null is not for an application”

问题:

I'm trying to open a dialog window, but every time I try to open it it throws this exception:

Uncaught handler: thread main exiting due to uncaught exception android.view.WindowManager$BadTokenException:       Unable to add window -- token null is not for an application   at android.view.ViewRoot.setView(ViewRoot.java:460)   at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:177)   at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)   at android.app.Dialog.show(Dialog.java:238)   at android.app.Activity.showDialog(Activity.java:2413) 

I'm creating it by calling showDialog with the display's id. The onCreateDialog handler logs fine and I can step through it without an issue, but I've attached it since it seems like I'm missing something:

@Override public Dialog onCreateDialog(int id) {     Dialog dialog;     Context appContext = this.getApplicationContext();     switch(id)     {         case RENAME_DIALOG_ID:             Log.i("Edit", "Creating rename dialog...");             dialog = new Dialog(appContext);             dialog.setContentView(R.layout.rename);             dialog.setTitle("Rename " + noteName);             break;         default:             dialog = null;             break;     }     return dialog;       } 

Is there something missing from this? Some questions have talked about having this problem when creating a dialog from onCreate, which happens because the activity isn't created yet, but this is coming from a call from a menu object, and the appContext variable seems like it is correctly populated in the debugger.

回答1:

Instead of : Context appContext = this.getApplicationContext(); you should use a pointer to the activity you're in (probably this).

I got bitten by this today too, the annoying part is the getApplicationContext() is verbatim from developer.android.com :(

回答2:

You cannot display an application window/dialog through a Context that is not an Activity. Try passing a valid activity reference

回答3:

Ditto on the getApplicationContext thing.

The documents on the android site says to use it, but it doesn't work...grrrrr :-P

Just do:

dialog = new Dialog(this);  

"this" is usually your Activity from which you start the dialog.

回答4:

Android documents suggests to use getApplicationContext();

but it will not work instead of that use your current activity while instantiating AlertDialog.Builder or AlertDialog or Dialog...

Ex:

AlertDialog.Builder builder = new  AlertDialog.Builder(this); 

or

AlertDialog.Builder builder = new  AlertDialog.Builder((Your Activity).this); 

回答5:

Instead of getApplicationContext(), just use ActivityName.this

回答6:

I had a similar issue where I had another class something like this:

public class Something {   MyActivity myActivity;    public Something(MyActivity myActivity) {     this.myActivity=myActivity;   }    public void someMethod() {    .    .    AlertDialog.Builder builder = new AlertDialog.Builder(myActivity);    .    AlertDialog alert = builder.create();    alert.show();   } } 

Worked fine most of the time, but sometimes it crashed with the same error. Then I realise that in MyActivity I had...

public class MyActivity extends Activity {   public static Something something;    public void someMethod() {     if (something==null) {       something=new Something(this);     }   } } 

Because I was holding the object as static, a second run of the code was still holding the original version of the object, and thus was still referring to the original Activity, which no long existed.

Silly stupid mistake, especially as I really didn't need to be holding the object as static in the first place...

回答7:

Just change it into

AlertDialog.Builder alert_Categoryitem =      new AlertDialog.Builder(YourActivity.this); 

Instead of

AlertDialog.Builder alert_Categoryitem =      new AlertDialog.Builder(getApplicationContext()); 

回答8:

Another solution is to set the window type to a system dialog:

dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT); 

This requires the SYSTEM_ALERT_WINDOW permission:

As the docs say:

Very few applications should use this permission; these windows are intended for system-level interaction with the user.

This is a solution you should only use if you require a dialog that's not attached to an activity.

回答9:

Don't use getApplicationContext() on declaring dialouge

Always use this or your activity.this

回答10:

This Worked for me--

new AlertDialog.Builder(MainActivity.this)         .setMessage(Html.fromHtml("Spread Knowledge Unto The Last"))         .setCancelable(false)         .setPositiveButton("Dismiss",                 new DialogInterface.OnClickListener() {                     public void onClick(DialogInterface dialog, int id) {                     }                 }).show(); 

Use

ActivityName.this 

回答11:

For nested dialogs this issue is very common, It works when

AlertDialog.Builder mDialogBuilder = new AlertDialog.Builder(MyActivity.this); 

is used instead of

mDialogBuilder = new AlertDialog.Builder(getApplicationContext); 

this alternative.

回答12:

You can also do this

public class Example extends Activity {     final Context context = this;     final Dialog dialog = new Dialog(context); } 

This worked for me !!

回答13:

As it's said, you need an Activity as context for the dialog, use "YourActivity.this" for a static context or check here for how to use a dynamic one in a safe mode

回答14:

Try to reset dialog window's type to

WindowManager.LayoutParams.TYPE_SYSTEM_ALERT: dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT); 

Don't forget to use the permission android.permission.SYSTEM_ALERT_WINDOW

回答15:

public class Splash extends Activity {      Location location;     LocationManager locationManager;     LocationListener locationlistener;     ImageView image_view;     ublic static ProgressDialog progressdialog;     @Override     protected void onCreate(Bundle savedInstanceState) {         // TODO Auto-generated method stub         super.onCreate(savedInstanceState);         setContentView(R.layout.splash);         progressdialog = new ProgressDialog(Splash.this);            image_view.setOnClickListener(new OnClickListener() {              @Override             public void onClick(View v) {                 // TODO Auto-generated method stub                          locationManager.requestLocationUpdates("gps", 100000, 1, locationlistener);                         Toast.makeText(getApplicationContext(), "Getting Location plz wait...", Toast.LENGTH_SHORT).show();                              progressdialog.setMessage("getting Location");                             progressdialog.show();                             Intent intent = new Intent(Splash.this,Show_LatLng.class); //                          }         });     } 

Text here:-
use this for getting activity context for progressdialog

 progressdialog = new ProgressDialog(Splash.this); 

or progressdialog = new ProgressDialog(this);

use this for getting application context for BroadcastListener not for progressdialog.

progressdialog = new ProgressDialog(getApplicationContext()); progressdialog = new ProgressDialog(getBaseContext()); 

回答16:

The best and the safest way to show a 'ProgressDialog' in an AsyncTask, avoiding memory leak problem is to use a 'Handler' with Looper.main().

    private ProgressDialog tProgressDialog; 

then in the 'onCreate'

    tProgressDialog = new ProgressDialog(this);     tProgressDialog.setMessage(getString(R.string.loading));     tProgressDialog.setIndeterminate(true); 

Now you r done with the setup part. Now call 'showProgress()' and 'hideProgress()' in AsyncTask.

    private void showProgress(){         new Handler(Looper.getMainLooper()){             @Override             public void handleMessage(Message msg) {                 tProgressDialog.show();             }         }.sendEmptyMessage(1);     }      private void hideProgress(){         new Handler(Looper.getMainLooper()){             @Override             public void handleMessage(Message msg) {                 tProgressDialog.dismiss();             }         }.sendEmptyMessage(1);     } 

文章来源: Android 1.6: “android.view.WindowManager$BadTokenException: Unable to add window ― token null is not for an application”