Android, Get result from third activity

Question

In first activity, there is empty ListView and Button.

When I press button, it starts second activity that has ListView of categories.

After I click into one of listElements it will start third activity that has ListView with elements that are belong to my chosen category.

When I choose element of third ListView it must send me back to first activity, where my chosen element is added to my empty ListView

Answer 1

Use Intent.FLAG_ACTIVITY_FORWARD_RESULT like this:

---

FirstActivity should start SecondActivity using startActivityForResult().

SecondActivity should start ThirdActivity using this:

Intent intent = new Intent(this, ThirdActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
startActivity(intent);
finish();

This tells ThirdActivity that it should return a result to FirstActivity.

ThirdActivity should return the result using

setResult(RESULT_OK, data);
finish();

At that point, FirstActivity.onActivityResult() will be called with the data returned from ThirdActivity.

Answer 2

Though I'd implore you to change your architecture design, it is possible to do it like this:

File ActivityOne.java

...
startActivityForResult(new Intent(this, ActivityTwo.class), 2);
...
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if(resultCode == RESULT_OK && data != null) {
        //Collect extras from the 'data' object
    }
}
...

File ActivityTwo.java

...
startActivityForResult(new Intent(this, ActivityTwo.class), 3);
...
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if(resultCode == RESULT_OK && data != null) {
        setResult(resultCode, data);
        finish();
    }
    setResult(RESULT_CANCELLED);
}
...

File ActivityThree.java

...
//Fill the Intent resultData with the data you need in the first activity
setResult(RESULT_OK, resultData);
finish();
...