iosuialertviewuialertviewdelegate

Show UIAlertView in delegate fails


I am calling a UIAlertView within it's own delegate and it is failing. The code is simple:

@interface ViewController () <UIAlertViewDelegate>
@property (nonatomic, strong) UIAlertView *alertView;
@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.alertView = [[UIAlertView alloc] initWithTitle:@"Howdy"
                                                message:@"Here's the alert"
                                               delegate:self
                                      cancelButtonTitle:@"Cancel"
                                      otherButtonTitles:@"OK", nil];
    [self.alertView show]; // this shows the 
}


- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
    if (buttonIndex == 1) {
        [self.alertView show]; // this does not show the alert again!
    }
}

@end

However, when I remove:

[self.alertView show] 

and replace it with:

[self.alertView performSelector:@selector(show) withObject:nil afterDelay:0.01]

it works.

This seems to indicate that the original UIAlertVIew is not completely dismissed even though I am inside the delegate method alertView:didDismissWithButtonIndex:.

While this is working, it does not seem right. Can anyone tell me what I am doing wrong?


Solution

  • You are probably right, but I don't see why would you show the same alert again. Since you usually do not require to keep a reference to an alert, you could just write a method like:

    - (void)showAlert {
       UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Howdy"
                                                       message:@"Here's the alert"
                                                      delegate:self
                                             cancelButtonTitle:@"Cancel"
                                             otherButtonTitles:@"OK", nil];
        [alert show];
    }
    

    It would also be better if you would call this from viewDidAppear instead of viewDidLoad.