在嵌入两个独立容器控制器的视图之间实现委派 [英] Implementing delegation between views embedded in two separate container controllers

问题描述

我的故事板的相关部分如下所示：

您可以看到自定义的容器控制器视图包含两个容器视图，一个通过嵌入式视图链接到导航控制器，另一个链接到自定义主视图控制器（实现表视图控制器）。导航控制器组件还与定制的位置过滤器控制器有关系。

The relevant part of my storyboard appears as follows: You can see the custom "Container Controller" view houses two Container Views, one which links to a Navigation Controller via embedded segue, and another that links to a custom "Master View Controller" (which implements a Table View Controller) via embedded segue. The Navigation Controller component further has a relationship with a custom "Location Filter Controller."

我需要实现委派，使得当位置过滤器控制器中的一个UISteppers incr./decr。主视图控制器中的表视图知道更新相应显示的数据。

I need to implement delegation such that when one of the UISteppers in the Location Filter Controller is incr./decr., the table view in the Master View Controller knows to update the data it displays accordingly.

我不习惯使用协议/代表，但是这种独特的交谈意见让人感到窒息！在大多数情况下，我已经成功地遵循以下示例：在视图控制器之间传递数据 。然而，在这种情况下，我无法直接链接实例化的视图，就像他指出的那样，在传回数据后退步骤6中。

I am not unaccustomed to working with protocols/delegates, but this unique situation of talking between views housed in segues is really tricking me! For the most part I have had success following the example here: Passing Data between View Controllers. In this case however, I am not able to directly link instantiated views as he indicates to do in 'Passing Data Back' step 6.

我曾经考虑过使用单例对象每个这些视图都可以从中获取/设置必要的数据，但这里的问题是表视图不一定知道何时更新其内容，尽管有可能/应该更新的数据。

I had considered using a singleton object from which each of these views could get/set the necessary data, but the issue here is that the table view would not necessarily know when to update its contents, despite having data with which it could/should update.

这是一个来自ContainerController.m的代码片段，其中我设置了嵌入的段落：

Here is a code snippet from ContainerController.m where I setup the embedded segues to function:

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    DataHold *data = [[DataHold alloc] init]; // <-- this actually is a singleton object

    if([segue.identifier isEqualToString:@"locationEmbedSegue"])
    {

    }
    else if([segue.identifier isEqualToString:@"tableEmbedSegue"])
    {
        [[segue destinationViewController] setDelegate:data.detailTableViewController];
        // ^ This part actually sets up a delegate so that the table view (Master View Controller)
        // delegates to the detail view controller of the overarching split view controller
        // and tells it what to display when a row is pressed.
    }
}

感谢任何帮助！

推荐答案

我认为您是正确的轨道，将表格视图委托给您的位置过滤器控制器。

I think you are on the right track setting the table view delegate to your Location Filter Controller.

我发现使用嵌入式视图控制器的简单方法是为它们添加占位符属性，并在执行时设置这些属性。

I found that a simple way to work with embeded view controller is to add "placeholders" property for them, and set these property when the segue is "performed".

// MyContainerController.h
@property (strong, nonatomic) MyLocationFilterController *detailViewController;
@property (strong, nonatomic) UITableViewController *masterViewController;

// MyContainerController.m
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if([segue.identifier isEqualToString:@"locationEmbedSegue"])
    {
        UINavigationViewController *dest = (UINavigationViewController *)segue.destinationViewController;
        self.detailViewController = dest.topViewController;
    }
    else if([segue.identifier isEqualToString:@"tableEmbedSegue"])
    {
        self.masterViewController = (UITableViewController *)segue.destinationViewController;
        [self.masterViewController.tableView setDelegate:self.detailViewController];
    }
}

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