Question

我有一个名为vc0的视图控制器，如下所示：

[self presentViewController: vc1 animated: YES completion: nil];

在vc1中我有一个按钮来呈现另一个视图控制器：

[self presentViewController: vc2 animated: YES completion: nil];

然后在vc2中，我有一个关闭视图控制器的按钮：

[self dismissViewControllerAnimated:YES completion: ^{
// over here I call one method in vc1
}

正如预期的那样它会返回到vc1 ..但是vc1中有一个按钮可以通过解除视图控制器来回到vc0：

    [self dismissViewControllerAnimated:YES completion:nil];

但由于某种原因它不起作用，视图控制器不会被解雇回vc0。当我第一次出现vc1时，我可以按下按钮来关闭视图控制器，它可以工作。但是，当我按下按钮打开vc2，当我将vc2解除回vc1时，然后我按下按钮关闭视图控制器，即它不起作用。

对不起，如果问题有点不清楚，说出我想说的话有点难。

还有一件事：

我尝试在vc1中替换dismissViewControllerAnimated:来手动呈现vc0，但后来我在控制台中得到一条日志，说我正在尝试呈现vc0，但vc1的视图不在窗口层次结构中。这是什么意思？

感谢您的帮助！

更新：

在此案例中VC0为MenuMileIndexViewController - VC1为FlightViewController - VC2为BookmarksTableViewController

以下是涉及的代码：

MenuMileIndexViewController：

- (IBAction)goToOriginPage {

FlightRecorder *origin = [[FlightRecorder alloc] init];
[self presentViewController:origin animated:YES completion:nil];

}

飞行记录器：

    - (void)searchBarBookmarkButtonClicked:(UISearchBar *)searchBar {

        [self bringUpBookmarkkTable];
}

- (void) bringUpBookmarkkTable {

    BookmarkTableViewController *bookmarkTVC = [[BookmarkTableViewController alloc] init];

    [bookmarkTVC setModalTransitionStyle: UIModalTransitionStyleFlipHorizontal];

    [self presentViewController:bookmarkTVC animated:YES completion:nil];
}

- (IBAction)cancel {

[self dismissViewControllerAnimated:YES completion:nil];

}

- (void)endBookmarkProcessWithBookmarkCollection: (NSDictionary *)dict {

    presetBookmarkContext = [dict mutableCopy];

    bookmarkMode = YES;

    NSString *compiledText = nil;

    NSNumber *number1 = [NSNumber numberWithInt: 1];

    if ([dict objectForKey: @"bookmarkTag"] == number1) {

        compiledText = [NSString stringWithFormat: @"%@ to %@", [dict objectForKey: @"origin"], [dict objectForKey: @"destination"]];
    }
    else {

        compiledText = [NSString stringWithFormat: @"%@ to %@", [dict objectForKey: @"destination"], [dict objectForKey: @"origin"]];
    }

    compiledText = [compiledText stringByReplacingOccurrencesOfString:@"Origin: " withString:@""];

    compiledText = [compiledText stringByReplacingOccurrencesOfString:@"Destination: " withString:@""];

    flightContext = [NSDictionary dictionaryWithObjectsAndKeys: [dict objectForKey: @"miles"], @"miles", compiledText, @"location", [[NSUserDefaults standardUserDefaults] objectForKey: @"tempD"], @"date", nil];

    NSString *string = [NSString stringWithFormat: @"\nMiles: %.2f\nFlight: %@\nDate: %@", [[dict objectForKey: @"miles"] floatValue], compiledText, [[NSUserDefaults standardUserDefaults] objectForKey:@"tempD"]];

    UIAlertView *bvkBookmarkAlertView = [[UIAlertView alloc] initWithTitle:@"Confirmation" message:string delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:@"Add", nil];

    [bvkBookmarkAlertView show];
}



 - (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {

    if (buttonIndex == 1) {

        [self cancel]; // Even though cancel is an IBAction, IBAction is the same thing as void so it is callable
    }
}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {

    if (buttonIndex == 1) {

        [TheMileIndexViewController addDesiredMilesToIndex: [[flightContext objectForKey: @"miles"] doubleValue]];

        [TravelLogViewController addFlight: flightContext];

        if (!bookmarkMode) {

            if ([checkbox isSelected]) {

                [BookmarkHandler uploadBookmark: bookmarkFlightContext];
            }    
        }
    }

    if (buttonIndex == 0) {

        if ([alertView.title isEqualToString: @"Confirmation"]) {

            bookmarkMode = NO;
        }
    }

}

BookmarksTableViewController：

    - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

    [tableView deselectRowAtIndexPath:indexPath animated: YES];

    NSDictionary *dict = [[BookmarkHandler bookmarkCollection] objectAtIndex: indexPath.row];

    fl = [[FlightRecorder alloc] init];

    [self dismissViewControllerAnimated:YES completion:^{

        [fl endBookmarkProcessWithBookmarkCollection: dict];
    }];
}

现在，我已经在模拟器中创建了应用程序的屏幕录制，显示了问题所在。我可以通过电子邮件发送给您以供参考。所以我可以通过电子邮件发送给你。

Answer 1

我建议总是从VC中解雇一个实际呈现它的VC - 使用委托。这实际上也是Apple推荐的方式 - 正如我之前关于这个问题的回答中指出的那样。

因此，如果您有VC0呈现VC1，请使用委托方案解除VC0中的VC1代码。

我了解到这是处理呈现和解雇的最佳方式 - 即使有时它可以解除VC1本身内的VC1。

我问了一个非常相关的问题，你可能也有兴趣检查一下。它显示 code...

ps我还读到有些人只关闭VC1 - 这反过来也会解雇VC2。但是，如果我之前的建议有效，我就不会这样做。有时我在执行期间获得信息（没有崩溃）VC不再存在或与之相关的任何事情 - 所以我认为这不是最好的解决方案。但如果我的明确建议不起作用，你可以尝试第二个。

虽然不能保证这会持续更新到新的iOS，因为这个问题一直让我对几个iOS更新感到厌烦:-)，所以我决定采用标准推荐路线。

编辑：这是我修改后的代码 - 它没有问题 - 但是在用户响应警报后以及警报是否应该在VC1或VC0上时，不清楚您打算发生什么。无论如何使用委托和回调我没有看到任何问题。如果我错过了你的观点，请解释一下......

FlightViewControllerProtocol.h

@protocol FlightViewControllerProtocol <NSObject>
-(void) dismissVCAndEndBookmark;
@end

FlightViewController.m

#import "FlightViewController.h"
#import "FlightViewControllerProtocol.h"
#import "BookmarksTableViewController.h"
@interface FlightViewController ()

@end

@implementation FlightViewController
@synthesize delegate;

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

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

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

- (void)searchBarBookmarkButtonClicked:(UISearchBar *)searchBar {

    [self bringUpBookmarkkTable];
}

- (IBAction) bringUpBookmarkkTable {

    BookmarksTableViewController *bookmarkTVC = [[BookmarksTableViewController alloc] init];
    bookmarkTVC.delegate = self;
    [bookmarkTVC setModalTransitionStyle: UIModalTransitionStyleFlipHorizontal];

    [self presentViewController:bookmarkTVC animated:YES completion:nil];
}

- (IBAction)cancel {

    [self dismissViewControllerAnimated:YES completion:nil];

}

- (void)endBookmarkProcessWithBookmarkCollection: (NSDictionary *)dict {

//    presetBookmarkContext = [dict mutableCopy];

//    bookmarkMode = YES;

    NSString *compiledText = nil;

    NSNumber *number1 = [NSNumber numberWithInt: 1];

    if ([dict objectForKey: @"bookmarkTag"] == number1) {

        compiledText = @"Text1";
    }
    else {
        compiledText = @"Text2";
    }


//    flightContext = [NSDictionary dictionaryWithObjectsAndKeys: [dict objectForKey: @"miles"], @"miles", compiledText, @"location", [[NSUserDefaults standardUserDefaults] objectForKey: @"tempD"], @"date", nil];

    NSString *string = compiledText;

    UIAlertView *bvkBookmarkAlertView = [[UIAlertView alloc] initWithTitle:@"Confirmation" message:string delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:@"Add", nil];

    [bvkBookmarkAlertView show];
}


- (void) dismissVCAndEndBookmark {
    [self dismissViewControllerAnimated:YES completion:nil];
     [self endBookmarkProcessWithBookmarkCollection: nil];
}

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {

    if (buttonIndex == 1) {

        [self cancel]; // Even though cancel is an IBAction, IBAction is the same thing as void so it is callable
    }
}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {

    if (buttonIndex == 1) {

        NSLog(@"alertView1");
           }

    if (buttonIndex == 0) {
        NSLog(@"alertView2");

    }

}

@end

BookmarksTableViewController.h

 @interface BookmarksTableViewController : UIViewController
{
    id delegate;
}

@property (nonatomic,strong)   id delegate;

@end

BookmarksTableViewController.m

- (IBAction)goBack {
    [self.delegate dismissVCAndEndBookmark];
}

如果我理解你的意图，那么在BookmarksTableViewController.m中的回调似乎是你实现中的主要问题。

Answer 2

[self.navigationController popViewControllerAnimated:YES];

也为我做了伎俩。在我的情况下，我有一个（iPhone）viewController使用推送segue推入堆栈。由于启动segue的viewController有一个导航栏，我不得不向父控制器的navigationController发送popViewControllerAnimated消息，而不是调用它自己的dismissViewControllerAnimated：completion消息。

雷

Answer 3

第一视图：

首先在第一个视图中嵌入导航控制器。并使用此代码导航到另一个视图

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle: nil]; 
FirstView *rvc = [storyboard instantiateViewControllerWithIdentifier:@"apps"];
[self.navigationController pushViewController:rvc animated:YES];

第二种观点：

在解除视图的方法中添加此行

- (IBAction)back{
    [self.navigationController popViewControllerAnimated:YES];
}

dismissViewController：不工作

3 个答案: