Android: ProgressDialog.show() crashes with getApplicationContext

Question

I can't seem to grasp why this is happening. This code:

mProgressDialog = ProgressDialog.show(this, "", getString(R.string.loading), true);

works just fine. However, this code:

mProgressDialog = ProgressDialog.show(getApplicationContext(), "", getString(R.string.loading), true);

throws the following exception:

W/WindowManager(  569): Attempted to add window with non-application token WindowToken{438bee58 token=null}.  Aborting.
D/AndroidRuntime( 2049): Shutting down VM
W/dalvikvm( 2049): threadid=3: thread exiting with uncaught exception (group=0x4001aa28)
E/AndroidRuntime( 2049): Uncaught handler: thread main exiting due to uncaught exception
E/AndroidRuntime( 2049): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tastekid.TasteKid/com.tastekid.TasteKid.YouTube}: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
E/AndroidRuntime( 2049):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2401)
E/AndroidRuntime( 2049):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2417)
E/AndroidRuntime( 2049):    at android.app.ActivityThread.access$2100(ActivityThread.java:116)
E/AndroidRuntime( 2049):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1794)
E/AndroidRuntime( 2049):    at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime( 2049):    at android.os.Looper.loop(Looper.java:123)
E/AndroidRuntime( 2049):    at android.app.ActivityThread.main(ActivityThread.java:4203)
E/AndroidRuntime( 2049):    at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime( 2049):    at java.lang.reflect.Method.invoke(Method.java:521)
E/AndroidRuntime( 2049):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
E/AndroidRuntime( 2049):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
E/AndroidRuntime( 2049):    at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime( 2049): Caused by: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
E/AndroidRuntime( 2049):    at android.view.ViewRoot.setView(ViewRoot.java:460)
E/AndroidRuntime( 2049):    at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:177)
E/AndroidRuntime( 2049):    at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
E/AndroidRuntime( 2049):    at android.app.Dialog.show(Dialog.java:238)
E/AndroidRuntime( 2049):    at android.app.ProgressDialog.show(ProgressDialog.java:107)
E/AndroidRuntime( 2049):    at android.app.ProgressDialog.show(ProgressDialog.java:90)
E/AndroidRuntime( 2049):    at com.tastekid.TasteKid.YouTube.onCreate(YouTube.java:45)
E/AndroidRuntime( 2049):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)
E/AndroidRuntime( 2049):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364)
E/AndroidRuntime( 2049):    ... 11 more

Any ideas why this is happening? I'm calling this from the onCreate method.

Answer 1

Which API version are you using? If I'm right about what the problem is then this was fixed in Android 1.6 (API version 4).

It looks like the object reference that getApplicationContext() is returning just points to null. I think you're having a problem similar to one I had in that some of the code in the onCreate() is being run before the window is actually done being built. This is going to be a hack, but try launching a new Thread in a few hundred milliseconds (IIRC: 300-400 seemed to work for me, but you'll need to tinker) that opens your ProgressDialog and starts anything else you needed (eg. network IO). Something like this:

@Override
public void onCreate(Bundle savedInstanceState) {
    // do all your other stuff here

    new Handler().postDelayed(new Runnable() {
        @Override
        public void run() {
            mProgressDialog = ProgressDialog.show(YouTube.this.getApplicationContext(), "", YouTube.this.getString(R.string.loading), true);

            // start time consuming background process here
        }
    }, 1000); // starting it in 1 second
}

Answer 2

I don't think this is a timing issue around a null application context

Try extending Application within your app (or just use it if you already have)

public class MyApp extends Application

Make the instance available as a private singleton. This is never null

private static MyApp appInstance;

Make a static helper in MyApp (which will use the singleton)

    public static void showProgressDialog( CharSequence title, CharSequence message )
{
    prog = ProgressDialog.show(appInstance, title, message, true); // Never Do This!
}

BOOM!!

Also, check out android engineer's answer here: WindowManager$BadTokenException

One cause of this error may be trying to display an application window/dialog through a Context that is not an Activity.

Now, i agree, it does not make sense that the method takes a Context param, instead of Activity..

Answer 3

I am using Android version 2.1 with API Level 7. I faced with this (or similar) problem and solved by using this:

Dialog dialog = new Dialog(this);

instead of this:

Dialog dialog = new Dialog(getApplicationContext());

Hope this helps :)

Answer 4

Hi,

I have implemented Alert Dialog for exception throwing on to the current activitty view.Whenever I had given like this

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

Given same Window Exception.I write code for alert out of onCreate().So simple I used context = this; after setContentView() statement in onCreate() method.Taken context variable as global like Context context;

Code sample is

static Context context;

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


        setContentView(R.layout.network); 
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

        context = this;
.......

Alert Method Sample is

private void alertException(String execMsg){
        Log.i(TAG,"in alertException()..."+context);
        Log.e(TAG,"Exception :"+execMsg);
        AlertDialog.Builder builder = new AlertDialog.Builder(context);
.......

It works fine for me.Actually I searched for this error on StackOverflow I found this query.After reading all responses of this post, I tried this way so It works .I thought this is a simple solution for overcome the exception.

Thanks, Rajendar

Answer 5

What I did to get around this was to create a base class for all my activities where I store global data. In the first activity, I saved the context in a variable in my base class like so:

Base Class

public static Context myucontext; 

First Activity derived from the Base Class

mycontext = this

Then I use mycontext instead of getApplicationContext when creating dialogs.

AlertDialog alertDialog = new AlertDialog.Builder(mycontext).create();

Answer 6

I am creating a map view with itemized overlays. I was creating my itemizedoverlay like this from my mapActivity:

OCItemizedOverlay currentLocationOverlay = new OCItemizedOverlay(pin,getApplicationContext);

I found that I would get the "android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application" exception when my itemizedoverlay's onTap method was triggered(when the location is tapped on the mapview).

I found that if I simply passed, 'this' instead of 'getApplicationContext()' to my constructor, the problem went away. This seems to support alienjazzcat's conclusion. weird.

Answer 7

So if i try to show the dialog from a service it wont work?