iOS 分類添加屬性

1.首先在分類文件中導入頭文件 

　　#import <objc/runtime.h>

2.實現代碼如下:

(1).h定義文件

#import <UIKit/UIKit.h>

@interface UIView (Category)

/*
 * 基本數據類型
 */
@property (nonatomic,assign) CGFloat offset;

/*
 * 對象類型
 */
@property (nonatomic,copy)   NSString *name;

/*
 * 結構體(CGPoint)
 */
@property (nonatomic,assign) CGPoint point;

@end

 

(2).m實現文件

#import "UIView+Category.h"
#import <objc/runtime.h>

static NSString *offsetKey = @"offset";
static NSString *nameKey   = @"name";
static NSString *pointKey  = @"pointKey";

@implementation UIView (Category)

/*
 * 添加基本數據類型需要轉化為NSNumber類型
 */

- (void)setOffset:(CGFloat)offset {
    
    objc_setAssociatedObject(self, &offsetKey, @(offset), OBJC_ASSOCIATION_ASSIGN);
}

- (CGFloat)offset {
    
    NSNumber *numberValue = objc_getAssociatedObject(self, &offsetKey);
    return [numberValue intValue];
    
}

/*
 * 對象類型
 */
- (void)setName:(NSString *)name {
    
    objc_setAssociatedObject(self, &nameKey, name, OBJC_ASSOCIATION_COPY_NONATOMIC);
}

- (NSString *)name {
    
    return objc_getAssociatedObject(self, &nameKey);
}

/*
 * 添加結構體屬性
 * 需要包裝成NSValue
 */
- (void)setPoint:(CGPoint)point {
    
    NSValue *value = [NSValue value:&point withObjCType:@encode(CGPoint)];
    objc_setAssociatedObject(self,&pointKey, value, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
    
}

- (CGPoint)point {
    
    NSValue *value = objc_getAssociatedObject(self, &pointKey);
    if(value) {
        CGPoint point;
        [value getValue:&point];
        return point;
    }else {
        return CGPointZero;
    }
    
}

@end