How to get back the result from Child activity to Parent in android?

Question

I\'am starting a child activity on click of a button from Parent. And i\'am calculating some result (of type string) in child activity and finishing the child to come back t

Answer 1

In Parent Activity

Intent intent = new Intent(getApplicationContext(), yourChildActivity.class);
intent.putExtra("key", "value");
startActivityForResult(intent, ACTIVITY_CONSTANT);

in child activity to sent back result of your parent activity through

Intent data = new Intent();
data.putExtra("key1", "value1");
data.putExtra("key2", "value2");
// Activity finished return ok, return the data
setResult(RESULT_OK, data);
finish();

and get child activity result information in your parent activity

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK && requestCode == REQUEST_CODE) {
        if (data.hasExtra("key1") && data.hasExtra("key2")) {
            Toast.makeText(
                this,
                "Your reult is :  "data.getExtras().getString("key1") + " " + data.getExtras().getString("key2"),
                Toast.LENGTH_SHORT).show();
        }
    }
}

Answer 2

Instead of startActivityForResult(new Intent(ParentActivity.this, ChildActivity.class), ACTIVITY_CONSTANT);

You can use putExtras() method to pass values between activities:

In Child Activity:

Intent data = new Intent();
data.putExtra("myData1", "Data 1 value");
data.putExtra("myData2", "Data 2 value");
// Activity finished ok, return the data
setResult(RESULT_OK, data);
finish();

And in Parent activity, you can override onActivityResult() and inside that you can have Intent paramater and from the Intent parameter of this method you can retrieve the extra values passed from the child activity, such as intent.getStringExtra or intent.getSerializableExtra.

for example:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK && requestCode == REQUEST_CODE) {
        if (data.hasExtra("myData1")) {
            Toast.makeText(this, data.getExtras().getString("myData1"),
                Toast.LENGTH_SHORT).show();
        }
    }
}