什么是“代表”的替代方案在控制器之间传递数据？ [英] What are alternatives to "delegates" for passing data between controllers?

问题描述

有没有替代代表将数据从一个控制器传回到另一个控制器？

Are there alternatives to "delegates" to pass back data from one controller to another?

似乎很多工作实现代理只是为了传回来自一个子控制器，返回到父控制器。有没有其他方法？是块一个答案，如果是这样的代码将是很棒的。

Just seems like a lot of work implementing a delegate just to pass back the result from a child controller, back to the parent controller. Is there not another method? Are "blocks" one answer, and if so some example code would be great.

推荐答案

你可以使用很多方法： p>

You could use many ways:

1. 调用超级控制器的方法，需要投射可能


2. 通知


3. 简单关键价值观察


4. 核心资料

1. Calling a method of the super controller, needs casting maybe
2. Notifications
3. Simple Key-Value-Observing
4. Core Data

示例为1。

界面：为要传递的数据添加公共方法

- (void)newDataArrivedWithString:(NSString *)aString;

显示ChildController的MainViewController

- (void)showChildController
{
    ChildController *childController = [[ChildController alloc] init];
    childController.mainViewController = self;

    [self presentModalViewController:childController animated:YES];

    [childController release];
}

子控制器头/接口：为mainViewController添加一个属性

@class MainViewController;

@interface ChildController : UIViewController {
    MainViewController *mainViewController;   
}

@property (nonatomic, retain) MainViewController *mainViewController;

Child Controller将数据传递给MainViewController

- (void)passDataToMainViewController
{
    NSString * someDataToPass = @"foo!";
    [self.mainViewController newDataArrivedWithString:someDataToPass];
}

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