Question

我在Customer.h文件中定义了协议，如下所示：

@class Customer; 
@protocol CustomerDelegate <NSObject>

-(void) didSelectCustomer:(Customer *) customer; 

@end

@interface Customer : NSObject
{

}

@property (nonatomic,copy) NSString *name; 
@property (nonatomic,copy) NSString *occupation; 

@end

MasterViewController（左侧）调用didSelectCustomer方法，如下所示：

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    Customer *selectedCustomer = [customers objectAtIndex:[indexPath row]];
    [self.delegate didSelectCustomer:selectedCustomer]; 
}

现在，我需要告诉DetailViewController（右侧）做些什么。 DetailViewController符合CustomerDelegate协议。

@interface DetailViewController : UIViewController<UISplitViewControllerDelegate,CustomerDelegate>
{

}

-(void) didSelectCustomer:(Customer *)customer
{
    NSLog(@"sssdasdasdasd");
}

永远不会调用didSelectCustomer方法。我想我需要设置masterViewController.delegate = self，但我不知道在哪里设置这个东西。

更新1：

我在DetailViewController中添加了MasterViewController的实例，但它不起作用：

- (void)viewDidLoad
{
    [super viewDidLoad];    

    MasterViewController *master = [[MasterViewController alloc] init];
    master.delegate = self; 
}

解决方案：

在AppDelegate中：

  else 
    {
        UISplitViewController *splitViewController = (UISplitViewController *) self.window.rootViewController; 
        splitViewController.delegate = [splitViewController.viewControllers lastObject];



        UINavigationController *navigationController = [splitViewController.viewControllers lastObject];
       // splitViewController.delegate = (id)navigationController.topViewController;




        DetailViewController *detail =(DetailViewController *) [splitViewController.viewControllers lastObject];

        UINavigationController *masterNavigationController = [splitViewController.viewControllers objectAtIndex:0];

        MasterViewController *master = (MasterViewController *)masterNavigationController.topViewController;

        master.delegate = detail; 
    }

Answer 1

您从未明确声明自己是Consumer类的委托。仅仅符合它不会削减它。通过创建Consumer的实例在-viewDidLoad中声明它，可能是这样的：

-(void)viewDidLoad {
    Consumer *consumer = [[Consumer alloc]init];
    [consumer setDelegate:self];
}

您也不会在Consumer中为您的委托对象声明属性，因此永远不会实际访问它。首先这样做：

@class Customer; 
@protocol CustomerDelegate <NSObject>

-(void) didSelectCustomer:(Customer *) customer; 

@end

@interface Customer : NSObject
{

}

@property (nonatomic,copy) NSString *name; 
@property (nonatomic,copy) NSString *occupation; 
@property (weak) id <CustomerDelegate> delegate; //use assign or __unsafe_unretained if targeting <5.0.

@end

您可以检查您的班级是否符合您的协议：

if (![delegate conformsToProtocol:@protocol(CustomerDelegate)]) {
    [NSException raise:@"Delegate Exception"
                format:@"Parameter does not conform to CustomerDelegate protocol at line %d", (int)__LINE__];
}

Answer 2

拆分视图控制器的最后一个对象。

此对象返回UI导航控制器。

你知道，那你就可以自己做。

使用Storyboard在UISplitViewController中传递Master和Detail之间的值

2 个答案: