objective-c - 'unsafe_unretained 属性 'delegate' 的现有 ivar 'delegate' 必须是 __unsafe_unretained

Question

我遇到了上述错误，但不确定如何修复它。这是我的代码:

.h:

#import <UIKit/UIKit.h>

@protocol ColorLineDelegate <NSObject>

-(void)valueWasChangedToHue:(float)hue;

@end

@interface ColorLine : UIButton {

    id <ColorLineDelegate> delegate;

}

@property (nonatomic, assign) id <ColorLineDelegate> delegate;

@end

.m:

#import "ColorLine.h"

@implementation ColorLine

@synthesize delegate;

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

@end

错误发生在合成线。不过我找不到问题。

Answer 1

使用这个语法:

@interface SomeClass  : NSObject {
    id <SomeClassDelegate> __unsafe_unretained  delegate;
}
@property (unsafe_unretained) id <SomeClassDelegate> delegate;