本文主要介绍了两种改写UIButton的点击事件方法——继承UIButton跟给UIButton添加一个分类。附代码
方法一：继承UIButton
UIButtonBlock.h文件 如下
#import <UIKit/UIKit.h>
typedef void (^ClickActionBlock) (id obj);
@interface UIButtonBlock : UIButton
@property (nonatomic,strong)ClickActionBlock caBlock;
- (void)initWithBlock:(ClickActionBlock)clickBlock for:(UIControlEvents)event;
@end
UIButtonBlock.m文件如下：
#import "UIButtonBlock.h"
@implementation UIButtonBlock
- (void)initWithBlock:(ClickActionBlock)clickActionBlock for:(UIControlEvents)event{
[self addTarget:self action:@selector(goAction:) forControlEvents:event];
self.caBlock = clickActionBlock;
}
- (void)goAction:(UIButton *)btn{
self.caBlock(btn);
}
附使用方法。。。。。我这里是用storyboard拖出来的按钮。首先要在storyboard里的Button关联这个UIButtonBlock这个类
然后就是使用：
……
[self.clickButton initWithBlock:^(id obj) {
NSLog(@"继承之UIButton============%@",obj);
} for:UIControlEventTouchUpInside];
有同学觉得多此一举，这里不作解释。
方法二：给UIButton添加一个分类
UIButton+Block.h文件如下
#import <UIKit/UIKit.h>
typedef void (^ClickActionBlock) (id obj);
@interface UIButton (Block)
- (void)initWithBlock:(ClickActionBlock)clickBlock for:(UIControlEvents)event;
@end
UIButton+Block.m文件如下
#import "UIButton+Block.h"
#import <objc/runtime.h>
static id key;
@implementation UIButton (Block)
- (void)initWithBlock:(ClickActionBlock)clickBlock for:(UIControlEvents)event{
objc_setAssociatedObject(self, &key, clickBlock, OBJC_ASSOCIATION_COPY_NONATOMIC);
[self addTarget:self action:@selector(goAction:) forControlEvents:event];
}
- (void)goAction:(UIButton *)sender{
ClickActionBlock block = (ClickActionBlock)objc_getAssociatedObject(self, &key);
if (block) {
block(sender);
}
}
使用方法：
……
[self.blockButton initWithBlock:^(id obj) {
NSLog(@"Runtime block============%@",obj);
} for:UIControlEventTouchUpInside ];
方法一：使用注意如果手写的UIButton需要在UIButtonBlock中再写一个初始化方法。如果是从xib拖出来的是需要关联的。
两种方法都实现了通过块来实现UIButton的addtarget方法中的@select方法的回调。代码比较粗糙大家将就着看着。