给category添加基本数据类型属性

给category添加基本数据类型属性

说明

通常，我们添加属性都是通过对象扩展来实现的，其实，我们也可以用runtime来添加基本数据类型的属性

源码

//
//  UIView+AnimationProperty.h
//  RuntimeCategory
//
//  Created by YouXianMing on 15/7/8.
//  Copyright (c) 2015年 YouXianMing. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIView (AnimationProperty)

@property (nonatomic) CGFloat  scale;

@end

//
//  UIView+AnimationProperty.m
//  RuntimeCategory
//
//  Created by YouXianMing on 15/7/8.
//  Copyright (c) 2015年 YouXianMing. All rights reserved.
//

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

@implementation UIView (AnimationProperty)

NSString * const _recognizerScale = @"_recognizerScale";
- (void)setScale:(CGFloat)scale {

    objc_setAssociatedObject(self, (__bridge const void *)(_recognizerScale), @(scale), OBJC_ASSOCIATION_RETAIN_NONATOMIC);
    self.transform = CGAffineTransformMakeScale(scale, scale);
}
- (CGFloat)scale {

    NSNumber *scaleValue = objc_getAssociatedObject(self, (__bridge const void *)(_recognizerScale));
    return scaleValue.floatValue;
}

@end

//
//  ViewController.m
//  RuntimeCategory
//
//  Created by YouXianMing on 15/7/8.
//  Copyright (c) 2015年 YouXianMing. All rights reserved.
//

#import "ViewController.h"
#import "UIView+AnimationProperty.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    UIView *redView         = [[UIView alloc] initWithFrame:CGRectMake(, , , )];
    redView.backgroundColor = [UIColor redColor];
    [self.view addSubview:redView];

    UIView *greenView         = [[UIView alloc] initWithFrame:CGRectMake(, , , )];
    greenView.backgroundColor = [UIColor greenColor];
    greenView.scale           = 0.5f;
    [self.view addSubview:greenView];

}

@end

分析