找不到协议声明-iOS

当我尝试在下面两个类中使用协议时，编译器说找不到协议声明

视图控制器：

#import <UIKit/UIKit.h>
#import "SecondViewController.h"

@protocol FlipOtherSideViewControllerDelegate;

@interface ViewController : UIViewController<FlipsideViewControllerDelegate>     {
    id <FlipOtherSideViewControllerDelegate> __unsafe_unretained delegate;
}

- (IBAction)switchMode:(id)sender;
@property (unsafe_unretained) id <FlipOtherSideViewControllerDelegate> delegate;

@end

 @protocol FlipOtherSideViewControllerDelegate
- (void)flipothersideViewControllerDidFinish:(ViewController *)controller;
 @end

#import <UIKit/UIKit.h>
#import "ViewController.h"

@protocol FlipsideViewControllerDelegate;

@interface SecondViewController : UIViewController   <FlipOtherSideViewControllerDelegate> {
id <FlipsideViewControllerDelegate> __unsafe_unretained delegate;
}

@property (unsafe_unretained) id <FlipsideViewControllerDelegate> delegate;
@end

@protocol FlipsideViewControllerDelegate
- (void)flipsideViewControllerDidFinish:(SecondViewController *)controller;
@end

#导入
#导入“SecondViewController.h”
@协议FlipOtherSideViewControllerDelegate；
@界面ViewController:UIViewController{
id uu不安全u未获得授权的代表；
}
-（iAction）切换模式：（id）发送方；
@属性（不安全\未维护）id委托；
@结束
@协议FlipOtherSideViewControllerDelegate
-（void）FlipOtherSideViewControllerdFinish:（ViewController*）控制器；
@结束

第二视图控制器：

#import <UIKit/UIKit.h>
#import "SecondViewController.h"

@protocol FlipOtherSideViewControllerDelegate;

@interface ViewController : UIViewController<FlipsideViewControllerDelegate>     {
    id <FlipOtherSideViewControllerDelegate> __unsafe_unretained delegate;
}

- (IBAction)switchMode:(id)sender;
@property (unsafe_unretained) id <FlipOtherSideViewControllerDelegate> delegate;

@end

 @protocol FlipOtherSideViewControllerDelegate
- (void)flipothersideViewControllerDidFinish:(ViewController *)controller;
 @end

#import <UIKit/UIKit.h>
#import "ViewController.h"

@protocol FlipsideViewControllerDelegate;

@interface SecondViewController : UIViewController   <FlipOtherSideViewControllerDelegate> {
id <FlipsideViewControllerDelegate> __unsafe_unretained delegate;
}

@property (unsafe_unretained) id <FlipsideViewControllerDelegate> delegate;
@end

@protocol FlipsideViewControllerDelegate
- (void)flipsideViewControllerDidFinish:(SecondViewController *)controller;
@end

#导入
#导入“ViewController.h”
@协议FlipsideViewControllerDelegate；
@界面SecondViewController:UIViewController{
id uu不安全u未获得授权的代表；
}
@属性（不安全\未维护）id委托；
@结束
@协议FlipsideViewControllerDelegate
-（void）FlipSideViewControllerdFinish：（SecondViewController*）控制器；
@结束

以上有什么建议吗？

---

提前谢谢

为什么要在界面下方声明？尝试在接口声明之前进行声明。我认为应该没有任何错误。

您可以尝试执行声明

@protocol FlipSideViewControllerDeleteGate-（void）FlipSideViewControllerdFinish:（SecondViewController*）controller@结束

，而不仅仅是协议FlipsideViewControllerDelegate问题仍然存在！好的，看来您有递归导入问题，请尝试使用

@class ViewController。#导入“ViewController.h”

，反之亦然。并导入.m文件。这也不起作用。根据这一点，创建单独的文件可以解决这个问题。我的问题是，如何在协议中使用带有类参数的协议方法？例如：-（void）FlipSideViewControllerdFinish：（SecondViewController*）控制器；这是因为我想有一个协议方法，它有一个类类型的参数。。