How do I return to a calling activity if the user presses BACK?

My MAIN activity is spawning a child activity that contains a ListView. While this ListView is being populated (through an AsyncTask), an indeterminate progress bar is shown.

However, assuming that I am an impatient user and I press the BACK button, the progress bar is cancelled but I am left with a blank screen. I have to press BACK one more time to go back to the MAIN activity.

I would like the app to go back directly to the MAIN activity by pressing BACK only once. Can somebody point me in the right direction? I am thinking I should call finish() somewhere but I d开发者_如何学Con't know where to put it. Thanks in advance!

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Use setOnCancelListener() on Dialog (which ProgressDialog extends).

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you should override "onBackPressed()" it will call when the activity has detected the user's press of the back key.

@override
 public void onBackPressed(){
   this.startActivity(this,MainActivity.class);
 }

this code will call the MainActivity when emulator/ipphone back button pressed...

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you can try like this,place this code in your activities oncreate block.

findViewById(R.id.back).setOnClickListener(new OnClickListener() {
                    public void onClick(View v) {

                        finish();
                    }
                });