如何从appdelegate调用方法

Question

我有一个switch语句，利用nsuserdefaults bool函数来确定打开和关闭。我的问题是当switch key bool为yes时，如何在视图控制器中调用appdelegate.m方法。基本上在视图controller.m中调用第一个if语句中的appdelagte.m方法。

Appdelegate.m

- (void)application:(UIApplication *)app didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)devToken {
     TUPushHelper * helper = [[TUPushHelper alloc] initWithTokenData:devToken];
     [helper registerDevice];
}

Viewcontroller.m

if ([[NSUserDefaults standardUserDefaults] boolForKey:@"SwitchKey"]) {
    NSLog(@"ok");   
}
if (![[NSUserDefaults standardUserDefaults] boolForKey:@"SwitchKey"]) {
    [[UIApplication sharedApplication]unregisterForRemoteNotifications];   
}

Answer 1

[((AppDelegate*) [[UIApplication sharedApplication] delegate]) someMethod:nil];

并且不要忘记#import "AppDelegate.h

Answer 2

Bool isOn = [[NSUserDefaults standardUserDefaults] boolForKey:@"SwitchKey"];

if (isOn) {
    NSLog(@"ok");   
}


if (!isOn) {
    [[[UIApplication sharedApplication] delegate] unregisterForRemoteNotifications];   
}