AlertView: (UIAlertView *) alertView method does not work in Appdelegate

Question

I installed UIAlertView in the AppDelegate.m file.

But when I select the button on the warning screen.

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

did not work.

I installed UIAlertViewDelegate in the AppDelegate.h file.

and my AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:        (NSDictionary *)launchOptions
        {

         [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(reachabilityChanged:)
                                                 name:kReachabilityChangedNotification
                                               object:nil];

            NSString *remoteHostName = REACHABILITY_HOST;
            _hostReachability = [Reachability reachabilityWithHostName:remoteHostName];
            [_hostReachability startNotifier];

            return YES;
        }

        - (void) reachabilityChanged:(NSNotification *)note
        {
         if( [Reachability isExistNetwork] == NotReachable)
            {
                UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:nil         message:@"my message" delegate:nil cancelButtonTitle:@"ok"         otherButtonTitles:@"set",nil];
                [alertView show];

            }

        }

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

            switch (buttonIndex) {

                case 0:
                    NSLog(@"ok!");
                    break;

                    // set
                case 1:

                    NSLog(@"set!");
                    NSURL*url=[NSURL URLWithString:@"prefs:root=WIFI"];
                    [[UIApplication sharedApplication] openURL:url];
                    break;

            }
        }

But

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

did not introduce this method.

Does anyone know what happened? thank.

Answer 1

The warning delegate in the code is incorrectly set.

You need to modify the following line so that the delegate is the corresponding object (for example self):

UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:nil         message:@"my message" delegate:nil cancelButtonTitle:@"ok"         otherButtonTitles:@"set",nil];

Answer 2

You must replace the line

UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:nil message:@"my message" delegate:nil cancelButtonTitle:@"ok" otherButtonTitles:@"set",nil];
[alertView show];

On these lines

UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:nil message:@"my message" delegate:self cancelButtonTitle:@"ok" otherButtonTitles:@"set",nil];
[alertView show];

self, .

Answer 3

Check the delegate link in the .h file. Put on UIAlertViewDelegate.

@interface YourViewController : UIViewController<UIAlertViewDelegate>