ios - 从 Storyboard 中展开可防止委托(delegate)被调用

Question

我有一个 UIViewController 几个 segues 深，当使用完成时，应该 unwind 并将它们带回 DashboardViewController。

我在仪表板中创建了 unwindToDashboard 方法，并在我的 FinishViewController 中将一个按钮连接到 Exit。这样当它被点击时就会触发展开 Action 。

这很好。

但我需要将数据从 FinishViewController 传回 Dashboard。

所以我为 FinishViewController 创建了一个委托(delegate) ProcessDataDelegate 并使 Dashboard 符合它。

但是，仪表板中的委托(delegate)方法未被调用。

谁能告诉我我做错了什么？

DashboardViewController.m

#import "FinishViewController.h"

@interface DashboardViewController () <ProcessDataDelegate>{
    FinishViewController *fm;
}
@end

@implementation DashboardViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    if(!fm){
        fm = [[FinishViewController alloc] init];

    }

    fm.delegate = self;
}

- (IBAction)unwindToDashboard:(UIStoryboardSegue *)unwindSegue {
//empty
}

#pragma mark PROTOCOL METHODS

-(void) didFinishWithResults:(NSDictionary*) dictionary{
    NSLog(@"Dashboard method called didFinishWithResults");
}

@end

FinishViewController.h

@class FinishViewController;
@protocol ProcessDataDelegate <NSObject>
    @required
    - (void) didFinishWithResults: (NSDictionary*)dictionary;
@end

@interface FinishViewController : UIViewController 
@property (nonatomic, weak) id <ProcessDataDelegate>  delegate;
@end

FinishViewController.m

@interface FinishViewController () 
@end

@implementation FinishViewController

- (void)viewDidLoad {
    [super viewDidLoad];
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    NSLog(@"fired via the button to the exit--- Segue: %@", [segue identifier]);
    [delegate didFinishWithResults:nil ];
}

@end

Answer 1

您需要在 DashboardViewController 的 prepareForSegue 方法中传递您的委托(delegate)，在那里获取 destinationViewController 并转换为 FinishViewController 如果标识符等于你期望的 segue 标识符

像这样

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    NSLog(@"fired via the button to the exit--- Segue: %@", [segue identifier]);
    if([[segue identifier] isEqualToString:@"YourSegueIdentifier"])
    {
         ((FinishViewController*)[segue destinationViewController]).delegate = self
    }
}