UISplitView中的委托未被調用

Question

我已經設置了一個委托方法，以便從masterViewController到detailViewController進行通信，但是沒有調用委托方法。

MasterViewController.h

#import <UIKit/UIKit.h>

@class DetailViewController;
@class MasterViewController;

@protocol MasterViewControllerDelegate
- (void)SelectionChanged:(NSString *)url;
@end

@interface MasterViewController : UITableViewController

@property (nonatomic, weak) id<MasterViewControllerDelegate> delegate;
@property (strong, nonatomic) DetailViewController *detailViewController;

@end

然后在我的MasterViewController.m中，合成委托：

@synthesize delegate;

最后，我從我的didSelectRowAtIndexPath方法中調用委托方法，如下所示：

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSArray *links = [NSArray arrayWithObjects:
                      @"http://www.link1.com",
                      @"http://www.link2.com",
                      @"http://www.link3.com",
                      nil];

   [self.delegate SelectionChanged:[links objectAtIndex: indexPath.row]];
}

然后在我的DetailViewController.h中，我有：

@interface DetailViewController : UIViewController <UISplitViewControllerDelegate, MasterViewControllerDelegate>

在DetailViewController.m中：

- (void)SelectionChanged:(NSString *)url {
    NSLog(@"URL is %@", url);
}

當我運行應用程序時，從未調用SelectionChanged的NSLog ，也沒有出現任何錯誤。 有任何想法嗎？

Answer 1

好吧，我知道了...在我的AppDelegate.m文件中，我將以下內容添加到didFinishLaunchingWithOptions中

DetailViewController *detail = (DetailViewController *)navigationController.topViewController;
UINavigationController *masterNavigationController = [splitViewController.viewControllers objectAtIndex:0];
MasterViewController *master = (MasterViewController *)masterNavigationController.topViewController;

NSLog(@"%@",masterNavigationController.topViewController);
master.delegate = detail;

因此，整個方法如下所示：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    UISplitViewController *splitViewController = (UISplitViewController *)self.window.rootViewController;
    UINavigationController *navigationController = [splitViewController.viewControllers lastObject];
    splitViewController.delegate = (id)navigationController.topViewController;

    DetailViewController *detail = (DetailViewController *)navigationController.topViewController;
    UINavigationController *masterNavigationController = [splitViewController.viewControllers objectAtIndex:0];
    MasterViewController *master = (MasterViewController *)masterNavigationController.topViewController;

    NSLog(@"%@",masterNavigationController.topViewController);
    master.delegate = detail;

    return YES;
}

基本上，問題是我沒有在任何地方分配代表。