iOS 开发之协议-代理传值(3)

- (IBAction)pressCasting:(id)sender;

@end

其在WViewController.m的 - (IBAction)pressCasting:(id)sender 方法中调用WTwoViewController，并设置代理的回调方法，代码如下：

- (IBAction)pressCasting:(id)sender {
    WTwoViewController *controller = [[WTwoViewController alloc]initWithNibName:@"WTwoViewController" bundle:nil];
    controller.delegate = self;
   
    [self presentViewController:controller animated:YES completion:nil];
}

- (void)changeValue:(NSString *)value{
    // 改变UILabel的值
    self.lblValue.text = value;
}

OK，搞定。

这里只实现了从WTwoViewController到WViewController的传值，大家可以自己做做从WViewController到WTwoViewController的传值。

工程源码传送门DelegateByValue