委托(delegate)声明
// FolderListViewController.h
#import <UIKit/UIKit.h>
#import "Folder.h"
@protocol FolderSelectionDelegate <NSObject>
@required
- (void)setFolderFolder *)folder;
@end
@interface FolderListViewController : UITableViewController
@property (nonatomic, assign) id<FolderSelectionDelegate> delegate;
- (IBAction)showDashboardid)sender;
@end
从 didSelectRowAtIndexPath 调用委托(delegate):
// FolderListViewController.m
- (void)tableViewUITableView *)tableView didSelectRowAtIndexPathNSIndexPath *)indexPath {
[self.delegate setFolder:dataSource[indexPath.row]];
}
应该接收消息的 VC
#import <UIKit/UIKit.h>
#import "FolderListViewController.h"
#import "Folder.h"
@interface ProjectListViewController : UITableViewController <FolderSelectionDelegate, UISplitViewControllerDelegate, UISearchBarDelegate, UINavigationControllerDelegate>
@property (nonatomic,retain)UIActivityIndicatorView *activityIndicatorObject;
@property (nonatomic, copy)Folder *folder;
-(void)loadProjectsFolder*)folder;
@end
呈现 VC 的 Action
- (void)foldersButtonTapped {
UINavigationController *vc = [[UIStoryboard storyboardWithName"MainStoryboard_iPhone" bundle:nil] instantiateViewControllerWithIdentifier"FolderListNavController"];
vc.delegate = self;
[self presentViewController:vc animated:YES completion:nil];
}
委托(delegate)方法实现
- (void)setFolderFolder *)folder {
_folder = folder;
[self loadProjects:folder];
}
我已经阅读了这里的多个线程并且没有任何运气。起初,在展示 FolderListVC(即 vc.delegate = self)时,我没有提到 ProjectListVC 设置。不过,这似乎不是问题所在。我正在开发一个为 iPad 构建的应用程序,并将其扩展到所有设备上。此处的实现有效(它设置为 Split View Controller )。任何帮助将不胜感激
Best Answer-推荐答案 strong>
我认为 UINavigationcontroller 正在制造问题,因为它没有设置 FolderListViewController 委托(delegate)。你可以这样试试吗?
FolderListViewController *vc=[self.storyboard instantiateViewControllerWithIdentifier"FolderListViewController"];
vc.delegate=self; // protocol listener
[self.navigationController pushViewController:vc animated:YES];
关于ios - 无法从呈现的 View Controller 访问委托(delegate)方法,我们在Stack Overflow上找到一个类似的问题:
https://stackoverflow.com/questions/38769673/
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