iphone - 从第二个 ViewController 到第一个 ViewController

Question

我有 2 个 ViewController，第一个是 TableView，第二个是带有标签的按钮。当我单击第二个 ViewController 中的按钮时，我需要返回 TableView 并在

中设置

cell.detailTextLabel.text

按钮上标签的文本。

要返回到第一个 View ，我使用:

[self.navigationController popToViewController:[self.navigationController.viewControllers objectAtIndex:1] animated:YES];

但是我如何将第二个 View 中的标签设置为:

cell.detailTextLabel.text

第一眼？？？？？

Answer 1

我会在第二个 View Controller 中定义一个协议(protocol)和委托(delegate)

@protocol SecondViewController;

@interface SecondViewController : UIViewController

@property (nonatomic, assign) id<SecondViewController> delegate;

@end


@protocol SecondViewController <NSObject>
- (void)secondViewController:(SecondViewController *)controller didTappedOnButton:(UIButton *)button;
@end   

然后当点击按钮时调用委托(delegate):

- (IBAction)buttonTapped:(UIButton *)sender
{
    // do somthing..

    // then tell the delegate about the button tapped
    [self.delegate secondViewController:self didTappedOnButton:sender];
}  

在你的第一个 View Controller 中实现协议(protocol)

@interface FirstViewController : UIViewController <SecondViewControllerDelegate>

当你推送第二个 View Controller 时，将第一个设置为第二个委托(delegate):

- (void)someMethodThatPushTheSecondViewController
{
    SecondViewController *svc = [[SecondViewController alloc] init];
    [self.navigationController pushViewController:svc animated:YES];
    svc.delegate = self;
}  

并实现委托(delegate)方法在点击按钮时得到通知

- (void)secondViewController:(SecondViewController *)controller didTappedOnButton:(UIButton *)button
{
    // do somthing after button tapped
    // you can get the button title from button.titleLabel.text
}