通过 objc_setAssociatedObject alert 和 button关联 及传值

原文地址

http://blog.csdn.net/lengshengren/article/details/16886915

//唯一静态变量key

static const char associatedkey;

static const char associatedButtonkey;

- (IBAction)sendAlert:(id)sender

{

NSString *message =@"我知道你是按钮了";

UIAlertView *alert = [[UIAlertViewalloc]initWithTitle:@"提示"message:@"我要传值·"
delegate:selfcancelButtonTitle:@"确定" otherButtonTitles:nil];

alert.delegate =self;

[alert show];

//#import <objc/runtime.h>头文件

//objc_setAssociatedObject需要四个参数：源对象，关键字，关联的对象和一个关联策略。

//1
源对象alert

//2
关键字 唯一静态变量key associatedkey

//3
关联的对象 sender

//4
关键策略  OBJC_ASSOCIATION_RETAIN_NONATOMIC

objc_setAssociatedObject(alert, &associatedkey, message,OBJC_ASSOCIATION_RETAIN_NONATOMIC);

objc_setAssociatedObject(alert, &associatedButtonkey, sender,OBJC_ASSOCIATION_RETAIN_NONATOMIC);

}

-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex

{

//通过 objc_getAssociatedObject获取关联对象

NSString  *messageString =objc_getAssociatedObject(alertView, &associatedkey);

UIButton *sender = objc_getAssociatedObject(alertView, &associatedButtonkey);

_labebutton.text = [[sendertitleLabel]text];

_ThisLabel.text = messageString;

//使用函数objc_removeAssociatedObjects可以断开所有关联。通常情况下不建议使用这个函数，因为他会断开所有关联。只有在需要把对象恢复到“原始状态”的时候才会使用这个函数。

}

demo http://download.csdn.net/detail/lengshengren/6594365