block属性传值

SecondViewController.h

#warning第一步

//在第二个页面里声明block属性

@property(nonatomic,copy)void(^secondBlock)(NSString*str);

SecondViewController.m

-(void)didClickButton:(UIButton*)button{

#warning第二步

//在第二个页面里执行block回调,将@"路飞"传给第一个页面

self.secondBlock(@"路飞");

[self.navigationControllerpopViewControllerAnimated:YES];

}

RootViewController.m

-(void)didClickButton:(UIButton*)button{

SecondViewController* sec = [[SecondViewControlleralloc]init];

#warning第三步

//在第一个页面中实现block

//block回调

//得到block回传的string并赋给label

sec.secondBlock= ^(NSString* string){

self.label.text= string;

};

[self.navigationControllerpushViewController:secanimated:YES];

}

SecondViewController.m

-(void)dealloc{

#warning第四步

//Block释放

Block_release(_secondBlock);

[_textFieldrelease];

[superdealloc];

}