应用程序委托发出警告:“id<uiapplicationDelegate>”不符合“uiAlertViewDelegate”协议

@interface SomeAppDelegate : NSObject <UIApplicationDelegate, UIAlertViewDelegate> {

}

// ... rest of interface

@end

MyAppDelegate* appDelegate = [[UIApplication sharedApplication] delegate];

// what you want is:

MyAppDelegate* appDelegate = (MyAppDelegate*)[[UIApplication sharedApplication] delegate];

UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"My Title"
                                                    message:@"My message"
                                                   delegate:self cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil];
[alertView performSelectorOnMainThread:@selector(show) withObject:nil waitUntilDone:NO];