本文主要介紹了兩種改寫UIButton的點擊事件方法——繼承UIButton跟給UIButton添加一個分類。附代碼
方法一：繼承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。。。。。我這里是用storyboard拖出來的按鈕。首先要在storyboard里的Button關聯這個UIButtonBlock這個類
然后就是使用：
……
[self.clickButton initWithBlock:^(id obj) {
NSLog(@"繼承之UIButton============%@",obj);
} for:UIControlEventTouchUpInside];
有同學覺得多此一舉，這里不作解釋。
方法二：給UIButton添加一個分類
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：使用注意如果手寫的UIButton需要在UIButtonBlock中再寫一個初始化方法。如果是從xib拖出來的是需要關聯的。
兩種方法都實現了通過塊來實現UIButton的addtarget方法中的@select方法的回調。代碼比較粗糙大家將就着看着。