title: Want to perform some action only when the post is successful via UIActivityViewController in iPhone
body: <p>I am having an app in which i am using <code>UIActivityViewController</code>. </p>
  
  <p>This is the code i am using.</p>
  
  <pre><code> NSString *postText = @"My Text";
      NSArray *activityItems = @[postText];
  
      UIActivityViewController *activityController =
      [[UIActivityViewController alloc]
       initWithActivityItems:activityItems applicationActivities:nil];
      activityController.excludedActivityTypes = [NSArray arrayWithObjects:UIActivityTypePrint, UIActivityTypeCopyToPasteboard, UIActivityTypeAssignToContact, UIActivityTypeSaveToCameraRoll, nil];
      [self presentViewController:activityController
                         animated:YES completion:nil];
  </code></pre>
  
  <p>This works fine. When i open Twitter or E-Mail from <code>UIActivityViewController</code>, It shows the text i want to share and that is fine. </p>
  
  <p>But ,Now i want to perform some action in my DB only when the post is successful or The E-mail is sent successfully. </p>
  
  <p>How can i do that?</p>