在视图控制器之间传递数据 - iOS Xcode - 什么是好方法？
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Passing data between view controllers - iOS Xcode - what's a good way?
提问by ipatch
Alright, I'll try and make this as simple as possible (I was seeming to get the run around on chat.stackoveflow.com when I tried asking this question). I want to pass the text from a textfield in one viewcontroller to another viewcontroller.
好吧，我会尽量让这件事变得简单（当我尝试问这个问题时，我似乎在 chat.stackoveflow.com 上跑来跑去）。我想将文本从一个视图控制器中的文本字段传递到另一个视图控制器。
Should I use a Modelclass and store the the textfield.text in a Model.[h/m] files and then have the second view controller access the data stored in the model?
我应该使用Model类并将 textfield.text 存储在 Model.[h/m] 文件中，然后让第二个视图控制器访问存储在模型中的数据吗？
Basically this is what I have,
基本上这就是我所拥有的
ViewControllerWelcome.h
ViewControllerWelcome.h
@interface ViewControllerWelcome : UIViewController { }
@property (weak, nonatomic) IBOutlet UITextField *textFieldUsername;
ViewControllerWelcome.m
ViewControllerWelcome.m
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
ViewControllerHome *home = (ViewControllerHome *)[storyboard instantiateViewControllerWithIdentifier:@"Home"];
NSString *username = _textFieldUsername.text;
home.lblUSERNAME.text=username;
[self presentModalViewController:home animated:YES];
ViewControllerHome.h
视图控制器主页.h
@interface ViewControllerHome : UIViewController {
NSString *username;
UILabel *lblUSERNAME;
}
@property (weak, nonatomic) IBOutlet UILabel *lblUSERNAME;
ViewControllerHome.m
视图控制器主页.m
- (void)changeUSERNAME {
// get username from welcome tf
ViewControllerWelcome *welcome = [[ViewControllerWelcome alloc] init];
welcome.username = [self lblUSERNAME.text];
// _lblUSERNAME.text = welcome._textFieldUsername.text;
//welcome.textFieldUsername.text = _username;
// username = welcome.textFieldUsername.text;
NSLog(@"username = %@",username);
// welcome.textFieldUsername.text = _lblUSERNAME.text;
// NSLog(@"username = %@",welcome.textFieldUsername.text);
}
As you can see I tried several different things, but couldn't come up with a working solution :-l
如您所见，我尝试了几种不同的方法，但无法提出可行的解决方案：-l
采纳答案by ipatch
回答by carl_h
Since you're using Storyboards, it makes more sense to be using Segues to perform the transition between your ViewControllers. If you're not familiar with segues you can have a look here:
由于您使用的是 Storyboard，因此使用 Segues 在您的 ViewController 之间执行转换更有意义。如果你不熟悉 segues，你可以看看这里：
It's very simple to create a segue in IB. Once you have that set up you implement-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)senderand configure your destination view controller. So you'll have something like the following.
在 IB 中创建 segue 非常简单。完成设置后，您就可以实现-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender和配置目标视图控制器。所以你会得到类似下面的东西。
-(void)prepareForSegue(UIStoryboardSegue *)segue sender:(id)sender{
// Assume you have a viewHomeSegue defined that has the name of the segue you want to perform
NSString * segueIdentifier = [segue identifier];
if([segueIdentifier isEqualToString:viewHomeSegue]){
ViewControllerHome * homeController = (ViewControllerHome *)[segue destinationViewController];
homeController.lblUSERNAME.text = _textFieldUsername.text;
}
}
回答by Norbert
You shouldn't keep strong references between those two ViewControllers in both directions. What you can do, for example, is to declare a protocol in your ViewControllerWelcomewith a delegate in it. You could let the ViewControllerHomeinstanciate the other controller and then be its delegate which gets informed as soon as the user finished entering the username.
您不应该在这两个 ViewController 之间在两个方向上保持强引用。例如，您可以做的是在您的协议中声明一个ViewControllerWelcome带有委托的协议。你可以让ViewControllerHome另一个控制器实例化，然后成为它的代表，一旦用户完成输入用户名，它就会得到通知。
@protocol ViewControllerWelcomeDelegate <NSObject>
- (void) userNameEntered:(NSString *)userName;
@end
@interface ViewControllerWelcome : UIViewController
@property (nonatomic, weak) id <ViewControllerWelcomeDelegate> delegate;
...
@end
In your @implementation:
在您的@implementation 中：
- (BOOL)textFieldShouldReturn:(UITextField *)theTextField
{
[theTextField resignFirstResponder];
[delegate userNameEntered:theTextField.text];
return YES;
}
回答by tomidelucca
if you have a .storyboard file you can layout your views in there like with interface builder.
如果你有一个 .storyboard 文件，你可以像使用界面构建器一样在那里布局你的视图。
This documents really helped me out the first time:
这份文件第一次真的帮到了我：
Part 1: http://www.raywenderlich.com/5138/beginning-storyboards-in-ios-5-part-1
第 1 部分：http: //www.raywenderlich.com/5138/beginning-storyboards-in-ios-5-part-1
Part 2: http://www.raywenderlich.com/5191/beginning-storyboards-in-ios-5-part-2
第 2 部分：http: //www.raywenderlich.com/5191/beginning-storyboards-in-ios-5-part-2
If you only want to check out the segues part, I'd recommend you to read part 2 only.
如果您只想查看 segues 部分，我建议您只阅读第 2 部分。
