title: How to use CNContactPickerViewController with objective c?
body: <p>Hi I'm new to iOS development. I want to pick a contact from default contacts app. For that i created an application that lets user to pick a contact from the iPhone default contacts app. For iOS 9+ version, I'm using the following snipped.</p>
  
  <pre><code>- (IBAction)btnAction:(id)sender {
  
      CNContactPickerViewController *contactPicker = [[CNContactPickerViewController alloc] init];
  
      contactPicker.delegate = self;
      contactPicker.displayedPropertyKeys = (NSArray *)CNContactGivenNameKey;
  
      [self presentViewController:picker animated:YES completion:nil];
  }
  
  -(void) contactPicker:(CNContactPickerViewController *)picker didSelectContact:(CNContact *)contact{
      NSLog(@"Contact : %@",contact);
  }
  
  -(void)contactPickerDidCancel:(CNContactPickerViewController *)picker {
      NSLog(@"Cancelled");
  }
  </code></pre>
  
  <p>I also added CNContactPickerDelegate delegate in my uiviewcontroller. When i execute the above code, it opens the contacts app, But when Tap a contact the app becomes blank.</p>
  
  <p>Thanks in advance and can anyone please share your knowledge to use CNContactPickerViewController in Objective-C.</p>