android - How to show dialog after activity finishes

Question

Say we have two activities, Activity1 and Activity2.

In Activity1's onClick() method, we have a call to start Activity 2 if a certain button is pressed:

Intent myIntent = new Intent(Activity1.this, Activity2.class);
Activity1.this.startActivity(myIntent);

After finish() is called in Activity2, and Activity1 is resumed, I need a dialog to show in Activity1, as soon as it is resumed.

Before, I simply called showDialog(id) in the same block of Activity1's onClick() method:

public void onClick(View v) {
     if(v == addHole){
     //...
     Intent myIntent = new Intent(Activity1.this, Activity2.class);
     Activity1.this.startActivity(myIntent);
     showDialog(END_DIALOG_ID);
     }
}

The issue is, after Activity1 resumes, the dialog corresponding to END_DIALOG_ID is not visible, but the screen is darkened and unresponsive (as if the dialog were present), until the back key is pressed.

I have tried putting the showDialog() call in Activity1's onResume() and onRestart() methods, but these both crash the program.

I have also tried creating an AsyncTask method in Activity2, with the showDialog() call in its onPostExecute(), but the dialog is not visible in Activity2.

private class ShowDialogTask extends AsyncTask<Void, Void, Integer> {
    /** The system calls this to perform work in a worker thread and
     * delivers it the parameters given to AsyncTask.execute() */
    protected Integer doInBackground(Void... id) {
        //do nothing
        return END_DIALOG_ID;
    }

    /** The system calls this to perform work in the UI thread and delivers
     * the result from doInBackground() */
    protected void onPostExecute(Integer id) {
        super.onPostExecute(id);
        showDialog(id);

    }
}

I am now trying to implement this by calling

Activity1.this.startActivityForResult(myIntent, END_DIALOG_REQUEST);

with corresponding setResult() and onActivityResult() methods from Activity1, but it seems that there should be a better practice for implementing this. All I need is to have a dialog shown upon Activity2 finishing.

Thanks for any help you can provide.

Answer 1

Like you suggest, call startActivityForResult when starting Activity2. Then, override onActivityResult and check for RESULT_OK, and show your dialog box then. That's a perfectly acceptable practice for doing what you're looking to do.