ios - XCode 5.1.1 iOS 7.1 将数据发送到任一先前的 Controller

Question

<分区>

Answer 1

你必须创建自定义委托(delegate)

在 CViewController.h 中

@protocol SecondViewControllerDelegate <NSObject>

@required
- (void)dataFromController:(NSString *)data;

@end

@interface CViewController : UIViewController

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

@end

在 CViewController.m 中

- (IBAction)btnBackAction:(id)sender {

    if([_delegate respondsToSelector:@selector(dataFromController:)])
    {
        [_delegate dataFromController:@"Data Received"];
    }

    [self.navigationController popViewControllerAnimated:YES];
}

在 A 或 BViewController 中(你想从 C 返回的地方)

// not forget to import CViewController.h
@interface A OR BViewController : UIViewController<SecondViewControllerDelegate>

现在在 A 或 BViewController.m 中

// when you go to CViewController from A Oor B then you have to pass delegate like  
CView.delegate = self;

- (void)dataFromController:(NSString *)data
{
    // this method invokes when you come back from CViewController

    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(50, 50, 250, 50)];
    label.autoresizingMask = UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth|
    UIViewAutoresizingFlexibleBottomMargin;
    label.textAlignment = NSTextAlignmentCenter;
    label.text = [NSString stringWithFormat:@"Your data: %@", data]; 
    [self.view addSubview:label];    
}