Send data to activity which is running in background

Question

Having trouble passing data between activities. ListActivity is collecting data and when back button is pressed returns to MainActivity and then want to get that data via onResume method but I don't get anything.

How can this problem be solved?

ListActivity.java

    @Override
public void finish() {
    i = new Intent(ArrayListActivity.this, MainActivity.class);
    i.putParcelableArrayListExtra(Constants.TAG_SELECTED_PRODUCT_LIST, selected_list);
    super.finish();
}

MainActivity.java

    @Override
protected void onResume() {
    super.onResume();

    Bundle extras = getIntent().getExtras().getBundle(Constants.TAG_SELECTED_PRODUCT_LIST);
    if(extras != null) {
        selected_list = extras.getParcelableArrayList(Constants.TAG_SELECTED_PRODUCT_LIST);


        myListView.setAdapter(new ProductAdapter(MainActivity.this,
                    R.layout.array_lisviewt_item_row, selected_list));
    }
}

What flags are you using for your activities? Single Task, Single top etc.? — Gaurav Arora, Mar 26 '13 at 15:20

Ben Weiss · Accepted Answer · 2013-03-26T15:29:46.363

You probably want to start your second activity from the first one via the startActivityForResult(...) method.

This method allows you to transport results from a launched activity back to it's launching activity.

From the documentation:

Launch an activity for which you would like a result when it finished. When this activity exits, your onActivityResult() method will be called with the given requestCode. Using a negative requestCode is the same as calling startActivity(Intent) (the activity is not launched as a sub-activity).

score 2 · Answer 2 · answered Mar 26 '13 at 15:24

2

You'll want to start the activity with startActivityForResult() and override onActivityResult() to handle the data you return from the second Activity.

Check out this article on the Android developers site for more info.

answered Mar 26 '13 at 15:24

Robby Pond

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score 2 · Answer 3 · answered Mar 26 '13 at 15:41

Perhaps you should

Call your ListActivity with startActivityForResult(), from your MainActivity.
Once you finished working on the ListActivity, you call setResult() to set the data, followed by finish().

This will bring you back to your previous MainActivity. So how do you retrieve the data set by your ListActivity?

In MainActivity, override onActivityResult().

There's a brief explanation of this mechanism in Starting Activities and Getting Results.

Send data to activity which is running in background

3 Answers3

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