Question

我有一个UIImageView的子类，并希望将self作为参数传递给委托。我在MyImageView之前收到错误“Expected'）'”。我需要将对象传递给委托，以便委托可以从对象中读取某些属性。

#import <UIKit/UIKit.h>
@protocol MyImageViewDelegate <NSObject>
-(void) buttonPressedForView:(MyImageView *) imageView;  //line with ERROR...
@end

@interface MyImageView : UIImageView {
    id <MyImageViewDelegate> delegate;
    BOOL _imageMode;
}

@property (nonatomic,assign) id <MyImageViewDelegate> delegate;
@property (nonatomic,readonly) BOOL imageMode;

Answer 1

我认为在协议声明之前你需要MyImageView的前向声明。

@class MyImageView;

@protocol MyImageViewDelegate <NSObject>
    -(void) buttonPressedForView:(MyImageView *) imageView;
@end

Answer 2

也许你应该在定义MyImageView接口后定义协议？似乎该方法无法识别MyImageView类类型，或者只是在新的.h中定义协议并导入当前的.h。

Answer 3

尝试添加此内容：

#import <UIKit/UIKit.h>
@class MyImageView; <<ADD THIS LINE
@protocol MyImageViewDelegate <NSObject>
-(void) buttonPressedForView:(MyImageView *) imageView;  //line with ERROR...
@end

@interface MyImageView : UIImageView {
    id <MyImageViewDelegate> delegate;
    BOOL _imageMode;
}

@property (nonatomic,assign) id <MyImageViewDelegate> delegate;
@property (nonatomic,readonly) BOOL imageMode;

delegate for object将自己传递给委托

3 个答案: