App crashes on showing ProgressDialog in non-activity

Question

From my MainActivty I'm trying to call a method of non-activity class with the following line:

Context context;
context = getApplicationContext();
mClient.start(context);

In non activity-class:

 public void start(Context context) {

    final ProgressDialog startDialog;
    startDialog = new ProgressDialog(context);
    startDialog.setMessage("Loading...");
    startDialog.setCancelable(false);
    startDialog.show();

    mHandler.post(new Runnable () {
        @Override
        public void run() {

            Log.d(TAG,"Connecting to the server...");

            try {
                connect();
            } catch (Exception e) {

            }               

      startDialog.dismiss();

 }

The app crashes with the following message:

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

Where's the mistake?

no it is not possible. It it was a non-activity class you would have get a compile time error — Blackbelt, Oct 09 '14 at 10:03
it should be possible if you pass a context as argument to the non activity class — andreasperelli, Oct 09 '14 at 10:14
of course it is possible, but `new ProgressDialog(this);` implies differently — Blackbelt, Oct 09 '14 at 10:17

score 1 · Accepted Answer · answered Oct 09 '14 at 10:03

1

Pass context parameter in ProgressDialog,So Change

startDialog = new ProgressDialog(this);

to

startDialog = new ProgressDialog(context);

And in your mainActivity change

context = getApplicationContext();

to

context = MainActivty.this;

answered Oct 09 '14 at 10:03

Giru Bhai

14,370
5
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This seems to work. But I don't understand why context = getApplicationContext(); doesn't work. If I call it from MainActivity.this, it should save 'MainActivity.this' in context variable... – andreasperelli Oct 09 '14 at 10:18
1

@andreasperelli see this [When to call activity context OR application context?](http://stackoverflow.com/questions/7298731/when-to-call-activity-context-or-application-context) – Giru Bhai Oct 09 '14 at 10:19

score 1 · Answer 2 · answered Oct 09 '14 at 10:04

try to change this in your non-activity class .start(....) method

  startDialog = new ProgressDialog(context);

instead of

  startDialog = new ProgressDialog(this);

also you need to change in your mainActivity

  context = getApplicationContext();

to

 context = MainActivity.this;;

You need to pass context to create Progress Dialog in non-activity class

score 0 · Answer 3 · answered Oct 09 '14 at 10:04

0

startDialog = new ProgressDialog(context);

answered Oct 09 '14 at 10:04

Zied R.

4,964
2
36
67

App crashes on showing ProgressDialog in non-activity

3 Answers3