ios - 当前 View Controller 不适用于 ios 9

Question

当前 View Controller 不适用于 ios 9，当我按下按钮时，它不会重定向到当前 View Controller 。

为什么会这样？

I had tried the below code

 RegistrationViewController * viewController =[[UIStoryboard storyboardWithName:@"Registration" bundle:nil] instantiateViewControllerWithIdentifier:@"RegistrationViewController"];
 [self presentViewController:viewController animated:YES completion:nil];

I had also tried the below code

 UIStoryboard* storyboard = [UIStoryboard storyboardWithName:@"Registration"
                                                         bundle:nil];
 RegistrationViewController *add =
 [storyboard instantiateViewControllerWithIdentifier:@"RegistrationViewController"];
 [self presentViewController:add animated:YES completion:^{
        dispatch_async(dispatch_get_main_queue(), ^{
            [self presentViewController:add
                               animated:YES
                             completion:nil];
        });
  }];

编辑

My complete code here. I am using Xcode 7 and running it with ios 9

#import "LoginViewController.h"
#import "RegistrationViewController.h"

@interface LoginViewController ()

@end

@implementation LoginViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


- (IBAction)actionRegistrationClicked:(id)sender
{
    RegistrationViewController * viewController =[[UIStoryboard storyboardWithName:@"Registration" bundle:nil] instantiateViewControllerWithIdentifier:@"RegistrationViewController"];
     [self presentViewController:viewController animated:YES completion:nil];

}
@end

Registration view controller

#import "RegistrationViewController.h"

@interface RegistrationViewController ()

@end

@implementation RegistrationViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

Answer 1

确保 presentedViewController 为 nil。如果 presentedViewController 不是 nil，则将代码更改为以下内容。

RegistrationViewController * viewController =[[UIStoryboard storyboardWithName:@"Registration" bundle:nil] instantiateViewControllerWithIdentifier:@"RegistrationViewController"];

if ([self presentedViewController]) {
    [[self presentedViewController] dismissViewControllerAnimated:NO completion:^{
        dispatch_async(dispatch_get_main_queue(), ^{
            [self presentViewController:viewController animated:YES completion:nil];
        });
    }];
} else {
    [self presentViewController:viewController animated:YES completion:nil];

}