如何从我的视图控制器 class 访问在 AppDelegate class 中声明的对象?

How can I access an object declared in the AppDelegate class from my view controller class?

这是我的 AppDelegate.h:

@interface AppDelegate : UIResponder <UIApplicationDelegate> {
    ProductHandlerModel *handler;
}

@property (strong, nonatomic) UIWindow *window;

-(ProductHandlerModel*)getHandler;

@end

这是我的 AppDelegate.m:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
     handler = [[ProductHandlerModel alloc]init];
     return YES;
}

- (ProductHandlerModel*)getHandler {
     return handler;
}

如何从另一个 UIViewController class 访问此处理程序对象?

一样打电话
AppDelegate *delegate = (AppDelegate *) [[UIApplication sharedApplication] delegate];
[delegate getHandler];

或者像

一样直接打电话
[(AppDelegate *)[[UIApplication sharedApplication] delegate] getHandler];

别忘了导入。

#import "AppDelegate.h"