如何解决此循环依赖？

本文介绍了如何解决此循环依赖？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 29岁程序员，3月因学历无情被辞！ 我是iOS开发的新手，我遇到了头文件的问题。我的头文件遇到循环依赖问题。我的应用程序委托类包含一个指向我的视图控制器的指针，因为我必须在我的didFinishLaunchingWithOptions方法中设置一个视图控制器的属性...I'm new to iOS development and am running into an issue with my header files. I'm running into a circular dependency issue with my header files. My application delegate class contains a pointer to my view controller, since I have to set one of the view controller's properties in my didFinishLaunchingWithOptions method...//appDelegate.h //DISCLAIMER: THIS IS UNTESTED CODE AND WRITTEN ON THE FLY TO ILLUSTRATE MY POINT#import <UIKit/UIKit.h>#import "MyViewController.h"@interface appDelegate NSManagedObjectContext *managedObjectContext; MyViewController *viewController; BOOL myFlag;@end//appDelegate.m@implementation appDelegate- (BOOL)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{ viewController.managedObjectContext = self.managedObjectContext; . . .}@end在我的视图控制器中，我引用了 myFlag属性，这是我的app委托......And in my view controller, I reference the "myFlag" property, that's in my app delegate...//MyViewController.h#import "appDelegate.h" //<---circular dependency, causing "Expected specifier-qualifier-list before MyViewController" errors in my appDelegate header file@interface MyViewController: UIViewController{ NSManagedObjectContext *managedObjectContext;}@end//MyViewController.m@import "MyViewController.h"@implementation MyViewController- (void)viewWillAppear:(BOOL)animated{ [super viewWillAppear:animated]; ((appDelegate*)[[UIApplication sharedApplication] delegate]).myFlag = NO;}@end但是为了访问我的app委托中的myFlag属性，我需要导入app delegate的头文件。这就是造成循环依赖的原因。不确定如何解决这个问题，有没有人碰到这个？But in order to access the "myFlag" property in my app delegate, I need to import the app delegate's header file. This is what's causing the circular dependency. Not sure how to resolve this, has anyone run into this?提前感谢您的帮助！推荐答案不要 #importMyViewController.h在 appDelegate.h 。相反，向前声明该类。Don't #import "MyViewController.h" in appDelegate.h. Instead, forward-declare the class.@class MyViewController;@interface appDelegate NSManagedObjectContext *managedObjectContext; MyViewController *viewController; BOOL myFlag;@end此外，您不需要 #importappDelegate.h在 MyViewController.h 中，如果只需要引用 myFlag 实施中的/ code>属性。而是在 MyViewController.m 文件中导入它。Also, you don't need to #import "appDelegate.h" in MyViewController.h if all you need is to reference the myFlag property in the implementation. Instead, import it in the MyViewController.m file. 这篇关于如何解决此循环依赖？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！