StoryBoard 页面传值

如图新建一个viewController和DetailViewController

VC 和DetailVC 联线的Idetnifier 设置为：GoDetailVC

ViewController主要代码
- (IBAction)signInButtonTouched:(id)sender {
   [self performSegueWithIdentifier:@"GoDetailVC" sender:self];
}

#pragma mark - prepare segue
// A页面传值到B页面
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    [super prepareForSegue:segue sender:sender];
    if ([segue.identifier isEqualToString:@"GoDetailVC"]) {
        DetailViewController *detailVC = segue.destinationViewController;
        detailVC.passValue = self.usernameTextField.text;
    }
}

// B页面传值到A页面
-(IBAction)done:(UIStoryboardSegue *)segue{
    if ([segue.sourceViewController isKindOfClass:[DetailViewController class]]) {
        DetailViewController * svc = (DetailViewController *)segue.sourceViewController;
        self.passwordTextField.text = svc.textField.text;
    }
}

在StoryBoard中 DetailViewController的Done按钮 Action关联到 viewController的done方法 如图

1.在VC页面中第一个textField中输入值 点击 Sing in 按钮就会把值传到DetailViewController 的textField中显示出来。

2.在DetailViewController textField中修改值 点击Done 按钮就会把值回传到ViewController中

如果 是Present 方式要怎么传值勒。如图

用如下代码肯定传值行不通
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    [super prepareForSegue:segue sender:sender];
    if ([segue.identifier isEqualToString:@"GoDetailVC"]) {
        DetailViewController *detailVC = segue.destinationViewController;  // 因为这取出来的是NavigationController 不是DetailViewController

detailVC.passValue = self.usernameTextField.text; 
} 
}

所以修改为如下：

// A页面传值到B页面
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    [super prepareForSegue:segue sender:sender];
    if([[segue identifier] isEqualToString:@"GoDetailVC"])
    {
        NSArray *viewControllerArray = [segue.destinationViewController viewControllers];
        DetailViewController *detailVC = [viewControllerArray objectAtIndex:];
        detailVC.passValue = self.usernameTextField.text;
    }
}