Question

I’m invoking android native calculator from my app, how do i get result data from it.. means i started native calender like this, after finishing calculation i press back onActivityResult is executed and data returned is null, how to get calculated data.. Help me

Intent i = new Intent();
i.setClassName("com.android.calculator2",
            "com.android.calculator2.Calculator");
startActivityForResult(i, 1); 

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data); 
if(requestCode == 1){
    Log.i("CALCULATOR", "Result Data is"+ data);
 }       
}

Answer 1

After some testing, I’m starting to think that you can’t really get something back from the calculator. Calling something with startActivityForResult doesn’t mean it’s going to return something other than null and since there’s no way of getting out of the calculator other than pressing the back key, I think this is one of those cases.

The native calculator doesn’t seem to be calling setResult(RESULT_SUCESS,intent_with_data) which is the step needed to be able to retrieve this result. Easiest thing I can think of, since you’re wanting to do some calculation is to implement your own calculator class and call that one instead of the native one.

Calculators are easy to make and you have a zillion examples on the net. Just make sure you have an OK button that calls setResult(RESULT_SUCESS, intent_with_data) after you put extras to the intent with the result.

Warning

Be aware that you’re hardcoding a class name instead of calling an intent by specifying an action and URI. This may call the original calculator on the emulator and standard versions of Android, but manufacturers change those kinds of things and since no one is supposed to be calling them like you intend to with your intent, you may end up crashing the app.