UIAlertView first deprecated IOS 9

Question

I have tried several ways to use UIAlertController,instead of UIAlertView. I tried several ways but I cannot make the alert action work. Here is my code that works fine in I

Answer 1

//Calling     
[self showMessage:@"There is no internet connection for this device"
                    withTitle:@"Error"];

//Method

-(void)showMessage:(NSString*)message withTitle:(NSString *)title
{

 UIAlertController * alert=   [UIAlertController
                                  alertControllerWithTitle:title
                                  message:message
                                  preferredStyle:UIAlertControllerStyleAlert];

    UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action){

        //do something when click button
    }];
    [alert addAction:okAction];
    UIViewController *vc = [[[[UIApplication sharedApplication] delegate] window] rootViewController];
    [vc presentViewController:alert animated:YES completion:nil];
}

If you want to use this alert in NSObject class you should use like:

-(void)showMessage:(NSString*)message withTitle:(NSString *)title{
dispatch_async(dispatch_get_main_queue(), ^{
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

    }]];

    [[[[UIApplication sharedApplication] keyWindow] rootViewController] presentViewController:alertController animated:YES completion:^{
    }];
});
}

Answer 2

Swift version of new implementation is :

 let alert = UIAlertController(title: "Oops!", message:"your message", preferredStyle: .Alert)
 alert.addAction(UIAlertAction(title: "Okay.", style: .Default) { _ in })
 self.presentViewController(alert, animated: true){}

Answer 3

From iOS8 Apple provide new UIAlertController class which you can use instead of UIAlertView which is now deprecated, it is also stated in deprecation message:

UIAlertView is deprecated. Use UIAlertController with a preferredStyle of UIAlertControllerStyleAlert instead

So you should use something like this

UIAlertController * alert = [UIAlertController
                alertControllerWithTitle:@"Title"
                                 message:@"Message"
                          preferredStyle:UIAlertControllerStyleAlert];



UIAlertAction* yesButton = [UIAlertAction
                    actionWithTitle:@"Yes, please"
                              style:UIAlertActionStyleDefault
                            handler:^(UIAlertAction * action) {
                                //Handle your yes please button action here
                            }];

UIAlertAction* noButton = [UIAlertAction
                        actionWithTitle:@"No, thanks"
                                  style:UIAlertActionStyleDefault
                                handler:^(UIAlertAction * action) {
                                   //Handle no, thanks button                
                                }];

[alert addAction:yesButton];
[alert addAction:noButton];

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

Answer 4

I tried the above methods, and no one can show the alert view, only when I put the presentViewController: method in a dispatch_async sentence:

dispatch_async(dispatch_get_main_queue(), ^ { [self presentViewController:alert animated:YES completion:nil]; });

Refer to Alternative to UIAlertView for iOS 9?.