Question

我一直想着我遇到的一种依赖。我是Objective-C的新手，所以请放轻松我。我甚至不知道如何谷歌我遇到的问题。

我有三个班级：

RootViewController
HttpRequestWrapper
ManagementClass

RootViewController继承ManagementClass的位置。（@interface RootViewController : ManagementClass <UINavigationControllerDelegate>）。

所以在ManagementClass我称这个函数为：

[[self.navigationController topViewController] getTableData];

其中topViewController是RootViewController（但稍后我想为任何topViewController更改它。）

此功能getTableData调用HttpRequestWrapper并在其URLConnection中调用其所有代理。但是当谈到委托方法时，(void)connectionDidFinishLoading:(NSURLConnection *)connection我希望NSNotification通知RootViewController从请求中加载数据并使用数据填充表。但是NSNotification即使在导航堆栈上是RootViewController，也不会通知topViewController。

所以我的问题是如何将数据从URLConnection恢复回RootViewController，即使请求是通过ManagementClass以某种方式初始化的。

以下是我的问题的一些代码：

班级RootViewController：

#import "RootViewController.h"
......

//  Get the data using the class HttpRequstWrapper (where I wrap the request in NSURLConnection)
- (void) getTableData{
    httpRequestWrapper = [HttpRequestWrapper alloc];
    [httpRequestWrapper getXMLDataWithURL:[NSString stringWithFormat:@"equipment/xml"]];
}
- (void) viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    // Get Table Data
    [self getTableData];
}

- (void) populateTableData{

    // Maybe change this line that error is shown if no data is found 
           if (httpRequestWrapper.dataFromTheHttpRequest == nil){
        NSLog(@"Data got from the HttpRequestWrapper is nil or empty");
    }

    // Parse the returned data 
    xmlcont = [[XMLController alloc] loadXMLByURL:httpRequestWrapper.dataFromTheHttpRequest];

    // Get the names of the Equipments as names of each Section
    arrayEquipments = [NSMutableArray alloc];
    arrayEquipments = xmlcont.equipments;
    sectionsTitles = [[NSMutableArray alloc]init];
    for (Equipment *eq in arrayEquipments){
        [sectionsTitles addObject: eq.equipmentName];
    }

    // Reload the data in TableView
    [self.tableView reloadData];
}

- (void) viewDidLoad{
    ....
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(populateTableData) name:@"connectionFinishedLoading" object:nil];

}

班级ManagementClass：在.h文件中

@interface ManagementClass : UITableViewController {}

@implementation ManagementClass

- (void) refreshPage {
    if ([[self.navigationController topViewController] isKindOfClass: [RootViewController class]]){ 
        [[self.navigationController topViewController] getTableData];
    } 
}

在HttpRequestWrapper课程中我有：

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
......
      if ([urlExtension rangeOfString: @"notification"].location != NSNotFound) {
            [[NSNotificationCenter defaultCenter] postNotificationName:@"connectionFinishedLoading1" object:nil];
        } else if ([urlExtension rangeOfString: @"execution/workflow"].location != NSNotFound) {
            [[NSNotificationCenter defaultCenter] postNotificationName:@"connectionFinishedLoadingPhaseView" object:nil]; execution/workflow

        } else if ([urlExtension rangeOfString: @"equipment/xml"].location != NSNotFound) {
        //[[self.navigationController topViewController] populateTableData];  - not working
        [[NSNotificationCenter defaultCenter] postNotificationName:@"connectionFinishedLoading" object:nil];
    }
.......
}

我想要一种让控制器尽可能重用的方法。我想到[[self.navigationController topViewController] populateTableData]放在connectionDidFinishLoading但导航控制器无法从HttpRequstWrapper调用，它根本就不执行。我仍然无法弄清楚为什么。我只能使用目前可见的navigationController的{{1}}执行ViewController方法。

Answer 1

从我看到的，你正在RootViewController中监听“connectionFinishedLoading”，你在HttpRequestWrapper中发布了“connectionFinishedLoading1”。它们必须与RootViewController

相同

三类依赖 - 返回数据

1 个答案: