Alert view in iphone

Question

I am new to iPhone application development. I want to design an alert view with 2 buttons: OK and Cancel. When the user touches the OK button, then I will print a message that says hello. When they touch the Cancel button, I will print cancel.

Please help; how do I do this?

Answer 1

To show the alert:

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Do you want to say hello?"
                                                message:@"More info..."
                                               delegate:self
                                      cancelButtonTitle:@"Cancel"
                                      otherButtonTitles:@"Say Hello",nil];
[alert show];
[alert release];

To respond to whatever button was tapped:

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {
    if (buttonIndex == 0) {
        NSLog(@"Cancel Tapped.");
    }
    else if (buttonIndex == 1) {
        NSLog(@"OK Tapped. Hello World!");
    }
}

For more information, see the UIAlertView Class Reference and the UIAlertView Delegate Protocol Reference.

Answer 2

since the chosen answer is deprecated, here is the new solution:

UIAlertController* alert = [UIAlertController alertControllerWithTitle:@"My Alert"
                               message:@"This is an alert."
                               preferredStyle:UIAlertControllerStyleAlert];

UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault
   handler:^(UIAlertAction * action) {}];

[alert addAction:defaultAction];
[self presentViewController:alert animated:YES completion:nil];

As shown in iOs Developer guide.

Answer 3

Show the alert with the following snippet

UIAlertView *alert = [[UIAlertView alloc]
   initWithTitle:@"Make an informed choice"
   message:nil
   delegate:self
   cancelButtonTitle:@"Cancel"
   otherButtonTitles:@"OK", nil];
[alert show];

The delegate is set to self so when the alert is dismissed our own class will get a call back. The delegate must implement the UIAlertViewDelegate protocol.

- (void)alertView:(UIAlertView *)alertView
   clickedButtonAtIndex:(NSInteger) buttonIndex{

   if (buttonIndex == 1) {
      // Do it!
   } else {
      // Cancel
   }
}