[plain]     [plain]      每次使用UIButton的點擊事件都要新寫一個方法，感覺太麻煩，今天下來無事就用block封裝了一下button的操作事件，這樣以後能省下一些時間，而且代碼量也減少了不少。 下面我寫上源碼：   我寫的是UIButton的類目   h文件：   [plain]   <p class="p1"><span class="s1">#import </span><UIKit/UIKit.h></p><p class="p2">   </p><p class="p3"><span class="s2">typedef</span> <span class="s2">void</span> (^ActionBlock)();</p><p class="p3"><span class="s2">typedef</span> <span class="s2">void</span> (^Block_SureEvent)();</p><p class="p2">   </p><p class="p3"><span class="s2">@interface</span> UIButton (Block)<<span class="s3">UIAlertViewDelegate</span>></p><p class="p3">-(<span class="s2">void</span>)handleClickEvent:(<span class="s3">UIControlEvents</span>)aEvent withClickBlick:(<span class="s4">ActionBlock</span>)buttonClickEvent;</p><p class="p3">-(<span class="s2">void</span>)AlertViewTitle:(<span class="s3">NSString</span> *)aTitle message:(<span class="s3">NSString</span> *)aMsg cancleButtonTitle:(<span class="s3">NSString</span> *)aButtonTitle sureButtonTitle:(<span class="s3">NSString</span> *)aSureButton sureBlockEvent:(<span class="s4">Block_SureEvent</span>)aSureEvent;</p><p class="p4">@end</p>    下面是m文件 [objc]   #import "UIButton+Block.h"   #import <objc/runtime.h>   static charchar *overViewKey;      @implementation UIButton (Block)   -(void)handleClickEvent:(UIControlEvents)aEvent withClickBlick:(ActionBlock)buttonClickEvent   {       objc_setAssociatedObject(self, &overViewKey, buttonClickEvent, OBJC_ASSOCIATION_COPY_NONATOMIC);       [self addTarget:self action:@selector(buttonClick) forControlEvents:aEvent];   }   -(void)buttonClick   {       ActionBlock blockClick = objc_getAssociatedObject(self, &overViewKey);       if (blockClick != nil)       {           blockClick();       }   }   @end   其中要想使用關聯對象的objc_setAssociatedObject和objc_getAssociatedObject必須引用頭文件objc/runtime.h objc_setAssociatedObject的四個參數分別為：源對象，key[必須是 static char類型]，關聯對象，關聯方式【與修飾屬性類似】 objc_getAssociatedObject的兩個參數：源對象，key。通過這兩個參數可以獲取關聯的對象。   --------------------------------AlertView----------------------Block-----------------------------------------   [objc]   <p class="p1"><span class="s1">static</span> <span class="s1">char</span> * alertKey;</p>   [objc]   -(void)AlertViewTitle:(NSString *)aTitle message:(NSString *)aMsg cancleButtonTitle:(NSString *)aButtonTitle sureButtonTitle:(NSString *)aSureButton sureBlockEvent:(Block_SureEvent)aSureEvent   {       UIAlertView * alert = [[UIAlertView alloc] initWithTitle:aTitle message:aMsg delegate:self cancelButtonTitle:aButtonTitle otherButtonTitles:aSureButton, nil nil];       objc_setAssociatedObject(self, &alertKey, aSureEvent, OBJC_ASSOCIATION_COPY_NONATOMIC);       [alert show];   }   - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex   {       if (buttonIndex == 1)       {                      Block_SureEvent blockSure = objc_getAssociatedObject(self, &alertKey);           if (blockSure != nil)           {               blockSure();           }           else           {               NSLog(@"error");           }                  }   }