在演示過程中出現？ 嘗試使用分析功能登錄Facebook后顯示新視圖。

Question

我正在嘗試呈現一個UITableView，供用戶放入數據並保存在解析中。 我很確定我不會顯示導航視圖。

登錄時出現錯誤：

Checklists[4516:c07] Warning: Attempt to present <ChecklistsViewController: 0x10525e90> 
on <UINavigationController: 0x9648270> while a presentation is in progress!

謝謝你的幫助。

#import "LoginViewController.h"
#import "ChecklistsViewController.h"
#import "SetupViewController.h"
#import <Parse/Parse.h>

@interface LoginViewController ()

@end

@implementation LoginViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    PFLogInViewController *login = [[PFLogInViewController alloc] init];
    login.fields = PFLogInFieldsFacebook;
    // Need to set the delegate to be this controller.
    login.delegate = self;
    login.signUpController.delegate = self; //signUpController is a property on the login view controller
    [self presentModalViewController:login animated:NO];

}

    - (void)logInViewController:(PFLogInViewController *)logInController didLogInUser:(PFUser *)user
{
    [self dismissModalViewControllerAnimated:YES];
    NSLog(@"Successfully logged in.");
    ChecklistsViewController *controller = [[ChecklistsViewController alloc] initWithStyle:UITableViewStylePlain];
    controller.modalTransitionStyle = UITableViewStylePlain;
    [self presentModalViewController:controller animated:YES];

}

Answer 1

這個方法已經被淘汰了好一陣子

     presentModalViewController:animated:

你應該改用這個

    presentViewController:animated:completion:

一樣

    dismissModalViewControllerAnimated:

現在我們用這個

    dismissViewControllerAnimated:completion:

當我們不需要完成塊時，只需將其設置為nil。

但是在您的情況下，完成塊可以解決您的問題……它可以確保事件的正確順序，即在解雇完成之前不會進行演示。

    - (void)logInViewController:(PFLogInViewController *)logInController 
                   didLogInUser:(PFUser *)user
{
    [self dismissViewControllerAnimated:YES completion:^{
        NSLog(@"Successfully logged in.");
        ChecklistsViewController *controller = 
              [[ChecklistsViewController alloc] initWithStyle:UITableViewStylePlain];
        controller.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
        [self presentViewController:controller animated:YES completion:nil];
    }];

}

[注意-modalTransitionStyle在您的原始代碼中不正確，我也對此進行了更改。 感謝Daniel G指出這一點]