Question

MyAlertView (subclass of UIAlertView) has this method:

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
    if (self.clickedButtonAtIndexBlock != NULL)
        self.clickedButtonAtIndexBlock(buttonIndex);
}

My question is how do I define the callback when I create the alert view? Obviously this is wrong:

alert.clickedButtonAtIndexBlock = ^{
    NSLog(@"clicked: %d", buttonIndex);
}

Answer 1

Try doing something like this (I haven’t tested it):

.h
typedef void (^MyClickedIndexBlock)(NSInteger index);

@interface YouInterface : YourSuperclass
@property (nonatomic, strong) MyClickedIndexBlock clickedIndexBlock;
@end

.m
//where you have to call the block
if (self.clickedIndexBlock != nil)
    self.clickedIndexBlock(buttonIndex);

// where you want to receive the callback
alert.clickedIndexBlock = ^(NSInteger index){
    NSLog(@"%d", index);
};