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

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 :(

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

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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.

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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);

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Instead of getApplicationContext(), just use ActivityName.this

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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...

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Just change it into

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

Instead of

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

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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:

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

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.

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Don't use getApplicationContext() on declaring dialouge

Always use this or your activity.this

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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.

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This Worked for me--

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

Use

ActivityName.this

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You can also do this

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

This worked for me !!

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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

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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

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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());

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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);
    }

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