iOS 7应用程序在objective-c中实现基本委派的步骤是什么？

我有

PeopleTableViewController

和

confirfiedTableViewController

PeopleTableViewController

：列出已确认的人员，仅供严格查看

ConfirmedTableViewController

：与上述相同，但具有挂起或删除的功能

我的目标是将在

confirfiedTableViewController

中所做的更改反映在

PeopleTableViewController

中，而无需重新启动应用程序。我最初通过使用parse.com

[self-loadObjects]

解决了这个问题，它将对对象所做的最新更改重新加载到我的tableView中使用的NSArray中

我将此方法放置在我的

视图中，将在
PeopleTableViewController
中显示
方法，当单击
PeopleTableController
选项卡将我带回其表视图时，它将被刷新

这导致我的应用程序的另一部分出现问题，因此必须将其删除。然后我寻找了一些其他的解决方案，发现了
NSNotificationCenter
。这对我来说非常有效，但我不喜欢事后需要移除观察者的想法。另外，使用委派也是有意义的，因为
PeopleTableViewController
是唯一需要知道在
ConfirmedTableViewController
中所做更改的类

我只是将其添加到数据库成功更新后触发的块中：

[[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(refreshTable) name:@"refreshTable" object:nil];

//MPConfirmedTableViewController.h

    #import <UIKit/UIKit.h>
    #import "Person.h"
    #import <Parse/Parse.h>

    @class MPConfirmedPeopleTableViewDelegate;

    @protocol MPConfirmedPeopleTableViewDelegate <NSObject>

    - (void)confirmedOrDeletedPerson;

    @end

    @interface MPConfirmedPeopleTableViewController : PFQueryTableViewController

    @property (nonatomic,weak) id <MPConfirmedPeopleTableViewDelegate> delegate;

    @end

// MPConfirmedTableViewController.m
    if (buttonIndex == 1) {
        [self showProgressHud];
        PFQuery *query = [PFQuery queryWithClassName:@"People"];
        // Retrieve the object by id
        [query getObjectInBackgroundWithId:[[self selectedPerson] objectId] block:^(PFObject *person, NSError *error) {

            if (!error) {
                // will get sent to the cloud.
                person[@"active"] = @0;
                [[self searchDisplayController] setActive:NO];
                [person saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
                    if (!error) {
                        [self loadObjects];
                        [[self delegate] performSelector:@selector(confirmedOrDeletedPerson)];
                     //   [[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];
                    } else {
                        [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                        [MBProgressHUD hideHUDForView:[self view] animated:YES];
                        [errorPopup show];

                    }
                }];

            } else {
                [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                [MBProgressHUD hideHUDForView:[self view] animated:YES];
                [errorPopup show];
            }
        }];

    }
}

//MPPeopleTableViewController.h
#import <UIKit/UIKit.h>
#import "Person.h"
#import "MPDisplayViewController.h"
#import <Parse/Parse.h>


@interface MPPeopleTableViewController : PFQueryTableViewController 
@end

// MPPeopleTableViewController

#import "MPPeopleTableViewController.h"
#import "MPContactFormViewController.h"
#import "MBProgressHUD.h"
#import "MPConfirmedPeopleTableViewController.h"

@interface MPPeopleTableViewController () <UISearchDisplayDelegate, UINavigationBarDelegate, UITabBarControllerDelegate, MPConfirmedPeopleTableViewDelegate>

@property (strong, nonatomic) IBOutlet UITableView *tableView;

@end

@implementation MPPeopleTableViewController

- (void)viewWillAppear:(BOOL)animated {
    MPConfirmedPeopleTableViewController *ctvc = [[MPConfirmedPeopleTableViewController alloc] init];
    [ctvc setDelegate: self];

}

- (void)confirmedOrDeletedPerson {
    NSLog(@"confirmed or deleted person");
    [self loadObjects];
}

然后，在我的视图中，我将在PeopleTableViewController中显示方法：

[[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(refreshTable) name:@"refreshTable" object:nil];

//MPConfirmedTableViewController.h

    #import <UIKit/UIKit.h>
    #import "Person.h"
    #import <Parse/Parse.h>

    @class MPConfirmedPeopleTableViewDelegate;

    @protocol MPConfirmedPeopleTableViewDelegate <NSObject>

    - (void)confirmedOrDeletedPerson;

    @end

    @interface MPConfirmedPeopleTableViewController : PFQueryTableViewController

    @property (nonatomic,weak) id <MPConfirmedPeopleTableViewDelegate> delegate;

    @end

// MPConfirmedTableViewController.m
    if (buttonIndex == 1) {
        [self showProgressHud];
        PFQuery *query = [PFQuery queryWithClassName:@"People"];
        // Retrieve the object by id
        [query getObjectInBackgroundWithId:[[self selectedPerson] objectId] block:^(PFObject *person, NSError *error) {

            if (!error) {
                // will get sent to the cloud.
                person[@"active"] = @0;
                [[self searchDisplayController] setActive:NO];
                [person saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
                    if (!error) {
                        [self loadObjects];
                        [[self delegate] performSelector:@selector(confirmedOrDeletedPerson)];
                     //   [[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];
                    } else {
                        [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                        [MBProgressHUD hideHUDForView:[self view] animated:YES];
                        [errorPopup show];

                    }
                }];

            } else {
                [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                [MBProgressHUD hideHUDForView:[self view] animated:YES];
                [errorPopup show];
            }
        }];

    }
}

//MPPeopleTableViewController.h
#import <UIKit/UIKit.h>
#import "Person.h"
#import "MPDisplayViewController.h"
#import <Parse/Parse.h>


@interface MPPeopleTableViewController : PFQueryTableViewController 
@end

// MPPeopleTableViewController

#import "MPPeopleTableViewController.h"
#import "MPContactFormViewController.h"
#import "MBProgressHUD.h"
#import "MPConfirmedPeopleTableViewController.h"

@interface MPPeopleTableViewController () <UISearchDisplayDelegate, UINavigationBarDelegate, UITabBarControllerDelegate, MPConfirmedPeopleTableViewDelegate>

@property (strong, nonatomic) IBOutlet UITableView *tableView;

@end

@implementation MPPeopleTableViewController

- (void)viewWillAppear:(BOOL)animated {
    MPConfirmedPeopleTableViewController *ctvc = [[MPConfirmedPeopleTableViewController alloc] init];
    [ctvc setDelegate: self];

}

- (void)confirmedOrDeletedPerson {
    NSLog(@"confirmed or deleted person");
    [self loadObjects];
}

上面的工作很好，但我想使用授权

以下是我的委派实施不起作用：

[[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(refreshTable) name:@"refreshTable" object:nil];

//MPConfirmedTableViewController.h

    #import <UIKit/UIKit.h>
    #import "Person.h"
    #import <Parse/Parse.h>

    @class MPConfirmedPeopleTableViewDelegate;

    @protocol MPConfirmedPeopleTableViewDelegate <NSObject>

    - (void)confirmedOrDeletedPerson;

    @end

    @interface MPConfirmedPeopleTableViewController : PFQueryTableViewController

    @property (nonatomic,weak) id <MPConfirmedPeopleTableViewDelegate> delegate;

    @end

// MPConfirmedTableViewController.m
    if (buttonIndex == 1) {
        [self showProgressHud];
        PFQuery *query = [PFQuery queryWithClassName:@"People"];
        // Retrieve the object by id
        [query getObjectInBackgroundWithId:[[self selectedPerson] objectId] block:^(PFObject *person, NSError *error) {

            if (!error) {
                // will get sent to the cloud.
                person[@"active"] = @0;
                [[self searchDisplayController] setActive:NO];
                [person saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
                    if (!error) {
                        [self loadObjects];
                        [[self delegate] performSelector:@selector(confirmedOrDeletedPerson)];
                     //   [[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];
                    } else {
                        [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                        [MBProgressHUD hideHUDForView:[self view] animated:YES];
                        [errorPopup show];

                    }
                }];

            } else {
                [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                [MBProgressHUD hideHUDForView:[self view] animated:YES];
                [errorPopup show];
            }
        }];

    }
}

//MPPeopleTableViewController.h
#import <UIKit/UIKit.h>
#import "Person.h"
#import "MPDisplayViewController.h"
#import <Parse/Parse.h>


@interface MPPeopleTableViewController : PFQueryTableViewController 
@end

// MPPeopleTableViewController

#import "MPPeopleTableViewController.h"
#import "MPContactFormViewController.h"
#import "MBProgressHUD.h"
#import "MPConfirmedPeopleTableViewController.h"

@interface MPPeopleTableViewController () <UISearchDisplayDelegate, UINavigationBarDelegate, UITabBarControllerDelegate, MPConfirmedPeopleTableViewDelegate>

@property (strong, nonatomic) IBOutlet UITableView *tableView;

@end

@implementation MPPeopleTableViewController

- (void)viewWillAppear:(BOOL)animated {
    MPConfirmedPeopleTableViewController *ctvc = [[MPConfirmedPeopleTableViewController alloc] init];
    [ctvc setDelegate: self];

}

- (void)confirmedOrDeletedPerson {
    NSLog(@"confirmed or deleted person");
    [self loadObjects];
}

保存要触发的方法的另一个控制器：

[[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(refreshTable) name:@"refreshTable" object:nil];

//MPConfirmedTableViewController.h

    #import <UIKit/UIKit.h>
    #import "Person.h"
    #import <Parse/Parse.h>

    @class MPConfirmedPeopleTableViewDelegate;

    @protocol MPConfirmedPeopleTableViewDelegate <NSObject>

    - (void)confirmedOrDeletedPerson;

    @end

    @interface MPConfirmedPeopleTableViewController : PFQueryTableViewController

    @property (nonatomic,weak) id <MPConfirmedPeopleTableViewDelegate> delegate;

    @end

// MPConfirmedTableViewController.m
    if (buttonIndex == 1) {
        [self showProgressHud];
        PFQuery *query = [PFQuery queryWithClassName:@"People"];
        // Retrieve the object by id
        [query getObjectInBackgroundWithId:[[self selectedPerson] objectId] block:^(PFObject *person, NSError *error) {

            if (!error) {
                // will get sent to the cloud.
                person[@"active"] = @0;
                [[self searchDisplayController] setActive:NO];
                [person saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
                    if (!error) {
                        [self loadObjects];
                        [[self delegate] performSelector:@selector(confirmedOrDeletedPerson)];
                     //   [[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];
                    } else {
                        [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                        [MBProgressHUD hideHUDForView:[self view] animated:YES];
                        [errorPopup show];

                    }
                }];

            } else {
                [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                [MBProgressHUD hideHUDForView:[self view] animated:YES];
                [errorPopup show];
            }
        }];

    }
}

//MPPeopleTableViewController.h
#import <UIKit/UIKit.h>
#import "Person.h"
#import "MPDisplayViewController.h"
#import <Parse/Parse.h>


@interface MPPeopleTableViewController : PFQueryTableViewController 
@end

// MPPeopleTableViewController

#import "MPPeopleTableViewController.h"
#import "MPContactFormViewController.h"
#import "MBProgressHUD.h"
#import "MPConfirmedPeopleTableViewController.h"

@interface MPPeopleTableViewController () <UISearchDisplayDelegate, UINavigationBarDelegate, UITabBarControllerDelegate, MPConfirmedPeopleTableViewDelegate>

@property (strong, nonatomic) IBOutlet UITableView *tableView;

@end

@implementation MPPeopleTableViewController

- (void)viewWillAppear:(BOOL)animated {
    MPConfirmedPeopleTableViewController *ctvc = [[MPConfirmedPeopleTableViewController alloc] init];
    [ctvc setDelegate: self];

}

- (void)confirmedOrDeletedPerson {
    NSLog(@"confirmed or deleted person");
    [self loadObjects];
}

//MPPeopleTableViewController.h
#进口
#输入“Person.h”
#导入“MPDisplayViewController.h”
#进口
@接口MPPeopleTableViewController:PFQueryTableViewController
@结束

我的实现：

[[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(refreshTable) name:@"refreshTable" object:nil];

//MPConfirmedTableViewController.h

    #import <UIKit/UIKit.h>
    #import "Person.h"
    #import <Parse/Parse.h>

    @class MPConfirmedPeopleTableViewDelegate;

    @protocol MPConfirmedPeopleTableViewDelegate <NSObject>

    - (void)confirmedOrDeletedPerson;

    @end

    @interface MPConfirmedPeopleTableViewController : PFQueryTableViewController

    @property (nonatomic,weak) id <MPConfirmedPeopleTableViewDelegate> delegate;

    @end

// MPConfirmedTableViewController.m
    if (buttonIndex == 1) {
        [self showProgressHud];
        PFQuery *query = [PFQuery queryWithClassName:@"People"];
        // Retrieve the object by id
        [query getObjectInBackgroundWithId:[[self selectedPerson] objectId] block:^(PFObject *person, NSError *error) {

            if (!error) {
                // will get sent to the cloud.
                person[@"active"] = @0;
                [[self searchDisplayController] setActive:NO];
                [person saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
                    if (!error) {
                        [self loadObjects];
                        [[self delegate] performSelector:@selector(confirmedOrDeletedPerson)];
                     //   [[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];
                    } else {
                        [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                        [MBProgressHUD hideHUDForView:[self view] animated:YES];
                        [errorPopup show];

                    }
                }];

            } else {
                [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                [MBProgressHUD hideHUDForView:[self view] animated:YES];
                [errorPopup show];
            }
        }];

    }
}

//MPPeopleTableViewController.h
#import <UIKit/UIKit.h>
#import "Person.h"
#import "MPDisplayViewController.h"
#import <Parse/Parse.h>


@interface MPPeopleTableViewController : PFQueryTableViewController 
@end

// MPPeopleTableViewController

#import "MPPeopleTableViewController.h"
#import "MPContactFormViewController.h"
#import "MBProgressHUD.h"
#import "MPConfirmedPeopleTableViewController.h"

@interface MPPeopleTableViewController () <UISearchDisplayDelegate, UINavigationBarDelegate, UITabBarControllerDelegate, MPConfirmedPeopleTableViewDelegate>

@property (strong, nonatomic) IBOutlet UITableView *tableView;

@end

@implementation MPPeopleTableViewController

- (void)viewWillAppear:(BOOL)animated {
    MPConfirmedPeopleTableViewController *ctvc = [[MPConfirmedPeopleTableViewController alloc] init];
    [ctvc setDelegate: self];

}

- (void)confirmedOrDeletedPerson {
    NSLog(@"confirmed or deleted person");
    [self loadObjects];
}

//MPPeopleTableViewController
#导入“MPPeopleTableViewController.h”
#导入“MPContactFormViewController.h”
#导入“MBProgressHUD.h”
#导入“MPConfirmedPeopleTableViewController.h”
@接口MPPeopleTableViewController（）
@属性（强，非原子）IBUITableView*tableView；
@结束
@MPPeopleTableViewController的实现
-（无效）视图将显示：（BOOL）动画{
MPConfirmedPeopleTableViewController*ctvc=[[MPConfirmedPeopleTableViewController alloc]init]；
[ctvc setDelegate:self]；
}
-（无效）确认人删除人{
NSLog（“确认或删除人”）；
[自动加载对象]；
}

发生的情况如下：

[[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(refreshTable) name:@"refreshTable" object:nil];

//MPConfirmedTableViewController.h

    #import <UIKit/UIKit.h>
    #import "Person.h"
    #import <Parse/Parse.h>

    @class MPConfirmedPeopleTableViewDelegate;

    @protocol MPConfirmedPeopleTableViewDelegate <NSObject>

    - (void)confirmedOrDeletedPerson;

    @end

    @interface MPConfirmedPeopleTableViewController : PFQueryTableViewController

    @property (nonatomic,weak) id <MPConfirmedPeopleTableViewDelegate> delegate;

    @end

// MPConfirmedTableViewController.m
    if (buttonIndex == 1) {
        [self showProgressHud];
        PFQuery *query = [PFQuery queryWithClassName:@"People"];
        // Retrieve the object by id
        [query getObjectInBackgroundWithId:[[self selectedPerson] objectId] block:^(PFObject *person, NSError *error) {

            if (!error) {
                // will get sent to the cloud.
                person[@"active"] = @0;
                [[self searchDisplayController] setActive:NO];
                [person saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
                    if (!error) {
                        [self loadObjects];
                        [[self delegate] performSelector:@selector(confirmedOrDeletedPerson)];
                     //   [[NSNotificationCenter defaultCenter] postNotificationName:@"refreshTable" object:nil];
                    } else {
                        [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                        [MBProgressHUD hideHUDForView:[self view] animated:YES];
                        [errorPopup show];

                    }
                }];

            } else {
                [[self tableView] setSeparatorStyle: UITableViewCellSeparatorStyleSingleLine];
                [MBProgressHUD hideHUDForView:[self view] animated:YES];
                [errorPopup show];
            }
        }];

    }
}

//MPPeopleTableViewController.h
#import <UIKit/UIKit.h>
#import "Person.h"
#import "MPDisplayViewController.h"
#import <Parse/Parse.h>


@interface MPPeopleTableViewController : PFQueryTableViewController 
@end

// MPPeopleTableViewController

#import "MPPeopleTableViewController.h"
#import "MPContactFormViewController.h"
#import "MBProgressHUD.h"
#import "MPConfirmedPeopleTableViewController.h"

@interface MPPeopleTableViewController () <UISearchDisplayDelegate, UINavigationBarDelegate, UITabBarControllerDelegate, MPConfirmedPeopleTableViewDelegate>

@property (strong, nonatomic) IBOutlet UITableView *tableView;

@end

@implementation MPPeopleTableViewController

- (void)viewWillAppear:(BOOL)animated {
    MPConfirmedPeopleTableViewController *ctvc = [[MPConfirmedPeopleTableViewController alloc] init];
    [ctvc setDelegate: self];

}

- (void)confirmedOrDeletedPerson {
    NSLog(@"confirmed or deleted person");
    [self loadObjects];
}

我单击
ConfirmedTableViewController
中的一行，就会触发一个actionsheet实例。该实例上的一个按钮是“takeoffline”，它将数据库中的一个值设置为0，这意味着该对象将不再显示在确认列表中

如果保存成功，我希望激活confirmedDeletedPerson方法，这样，如果我通过单击选项卡栏上与其关联的选项卡返回到
PeopleTableViewController
，我会看到
PeopleTableViewController
中反映的更改。然而，一切都没有发生。我错过什么了吗？我尝试过使用stackoverflow answers实现此功能的许多不同版本，但都没有成功

更新

TableViewController 6需要触发TableViewController 13中的方法。
因此TableViewController 6需要对TableViewController 13的引用

我正在创建一个新实例（盲目地遵循教程）。
这比使用通知中心要复杂得多，我想知道这样一个简单的任务是否值得这么麻烦

在
MPPeopleTableViewController
中，
视图将出现
方法正在创建
MPConfirmedPeopleTableViewController
的实例，但不保留它。实例将在
视图出现后释放。您需要定义一个属性来保存
mpconfirmedPeopleViewController
实例对象。此外，没有代码显示
MPConfirmedPeopleTableViewController
控制器

下面是一个应该可以工作的更新的实现

// MPPeopleTableViewController

#import "MPPeopleTableViewController.h"
#import "MPContactFormViewController.h"
#import "MBProgressHUD.h"

@interface MPPeopleTableViewController () <UISearchDisplayDelegate, UINavigationBarDelegate, UITabBarControllerDelegate>

@property (strong, nonatomic) IBOutlet UITableView *tableView;
@property (strong, nonatomic) MPConfirmedPeopleTableViewController *ctvc;
@end

@implementation MPPeopleTableViewController

- (void) viewDidLoad
{
    self.ctvc = [[MPConfirmedPeopleTableViewController alloc] init];
    [self.ctvc setDelegate: self];
}

- (void)viewWillAppear:(BOOL)animated {
    [self presentViewController:self.ctvc animated:YES completion:nil];
}

- (void)confirmedOrDeletedPerson {
    NSLog(@"confirmed or deleted person");
    [self loadObjects];
}

//MPPeopleTableViewController
#导入“MPPeopleTableViewController.h”
#导入“MPContactFormViewController.h”
#导入“MBProgressHUD.h”
@接口MPPeopleTableViewController（）
@属性（强，非原子）IBUITableView*tableView；
@属性（强，非原子）MPConfirmedPeopleTableViewController*ctvc；
@结束
@MPPeopleTableViewController的实现
-（无效）viewDidLoad
{
self.ctvc=[[MPConfirmedPeopleTableViewController alloc]init]；
[self.ctvc setDelegate:self]；
}
-（无效）视图将显示：（BOOL）动画{
[自我呈现视图控制器：self.ctvc动画：是完成：无]；
}
-（无效）确认人删除人{
NSLog（“确认或删除人”）；
[自动加载对象]；
}
只要像这样从save块调用该方法就足够了：

[self.delegate confirmedOrDeletedPerson];

无需将
MPConfirmedPeopleTableViewController
声明为
MPPeopleTableViewController
中的属性。我经常使用这种模式，通常不会像这样为视图控制器创建属性
 我不理解需要[self-presentViewController:self.ctvc动画：是完成：无]；tableView已经在那里了。这也给了我一个错误：原因：“***setObjectForKey:object不能为nil（键：classname）”创建MPConfirmedPeopleTableViewController的实例是不够的，您需要显示视图控制器。如果已经显示MPConfirmedPeopleTableViewController，例如作为导航控制器的根视图控制器，则必须创建和