从控制器传递值到控制器

Question

我正在构建我的第一个iOS应用程序来尝试和学习iOS编码。但是，我需要从一个控制器向另一个传递值xAuthToken。我似乎无法得到它的工作。我初始化了第一个控制器ViewController中的值，但是我需要它在SettingsController中。我不断收到错误，现在抛出的错误是：Property 'ViewController' not found on object of type 'ViewController'

我在做什么错？

ViewController.h

#import <UIKit/UIKit.h> 
#import "SettingsController.h" 

@interface ViewController : UIViewController <UITextFieldDelegate> 
@property (weak, nonatomic) IBOutlet UITextField *txtUsername; 
@property (weak, nonatomic) IBOutlet UITextField *txtPassword; 

- (IBAction)sigininClicked:(id)sender; 

- (IBAction)backgroundTap:(id)sender; 
@end 

ViewController.m

#import "ViewController.h" 

@interface ViewController() 

@property (nonatomic) NSString *xAuthToken; 

@end 

@implementation ViewController 

- (IBAction)sigininClicked:(id)sender { 

    NSString *xAuthToken = @"0"; 

    self.viewController = [[SettingsController alloc] init]; 
    self.viewController.xAuthToken = xAuthToken; 
    [self performSegueWithIdentifier:@"login_success" sender:self]; 

} 

SettingsController.h

#import <Foundation/Foundation.h> 

@interface SettingsController : UIViewController 

@end 

SettingsController.m

@interface SettingsController() 

@property (weak, nonatomic) IBOutlet UITextField *myTextField; 
@property (weak, nonatomic) IBOutlet UISwitch *mySwitch; 

@end 

@implementation SettingsController 

//THIS IS WHERE I NEED XAUTHTOKEN 

Answer 1

如果您有您呈现一个SettingsController赛格瑞，通过它在prepareForSegue需要的信息。不要创建新的本地SettingsController。

Answer 2

你可以做这样的事情

viewController = [self.storyboard instantiateviewcontrollerwithidentifier:@"your vc name"]; 
viewController.Xauthtoken = data; 
// Do something else with this. 

或者另一种方式（我不知道这是否是好还是坏，使用它，而你的VC已经被激活）： 使用NSNotificationCenter和它之间传递值。

第三种方法是为第一个Viewcontroller创建委托。

Answer 3

在ViewController.m试试这个：

#import "ViewController.h" 

@interface ViewController() 

@property (nonatomic) NSString *xAuthToken; 

@end 

@implementation ViewController 

- (IBAction)sigininClicked:(id)sender { 
    xAuthToken = @"Your Value Here"; 
    [self performSegueWithIdentifier:@"login_success" sender:self]; 
} 

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender { 
    if ([segue.identifier isEqualToString:@"login_success"]) { 
     SettingsController *destViewController = segue.destinationViewController; 
     destViewController.xAuthToken = xAuthToken; 
    } 
} 

而在你SettingsController.h

#import <Foundation/Foundation.h> 

@interface SettingsController : UIViewController 

@property (nonatomic,strong) NSString *xAuthToken; 

@end 

SettingsController.m

@interface SettingsController() 

@property (weak, nonatomic) IBOutlet UITextField *myTextField; 
@property (weak, nonatomic) IBOutlet UISwitch *mySwitch; 

@end 

@implementation SettingsController 

-(void)viewDidLoad{ 
    NSLog("%@",xAuthToken); 
}