使用UIView中的presentViewController

Question

我正在为我的iOS应用程序创建一个标题栏,我在UIView中创建它.我遇到的唯一问题是"主页按钮".按下主页按钮时,需要转到主页,即ViewController.

但是,它看起来并不[self presentViewController:vc animated:NO completion:NULL];适合UIView.

我该如何解决这个问题？

- (void) createTitlebar {

    CGRect titleBarFrame = CGRectMake(0, 0, 320, 55);

    //Create the home button on the top right of the page. When clicked, it will navigate to the home page of the application
    homeButton = [UIButton buttonWithType:UIButtonTypeCustom];
    homeButton.frame = CGRectMake(275, 10, 40, 40);
    [homeButton setTag:1];
    [homeButton setImage:[UIImage imageNamed:@"homeIcon.png"] forState:UIControlStateNormal];
    [homeButton addTarget:self action:@selector(homeButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
    [self addSubview:homeButton];
}

- (IBAction)homeButtonPressed:(id)sender{

    //Transition to the submit button page
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
    ViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"ViewController"];
    [vc setModalPresentationStyle:UIModalPresentationFullScreen];
    [self presentViewController:vc animated:NO completion:NULL];
}

Answer 1

您可以在不使用委托模式的情况下执行此操作.干得好

的ObjectiveC

UIViewController *currentTopVC = [self currentTopViewController];
currentTopVC.presentViewController......... 

- (UIViewController *)currentTopViewController {
    UIViewController *topVC = [[[[UIApplication sharedApplication] delegate] window] rootViewController];
    while (topVC.presentedViewController) {
        topVC = topVC.presentedViewController;
    }
    return topVC;
}

迅速

var topVC = UIApplication.sharedApplication().keyWindow?.rootViewController
while((topVC!.presentedViewController) != nil) {
     topVC = topVC!.presentedViewController
}
topVC?.presentViewController........

Answer 2

只有UIViewController可以呈现另一个视图控制器,所以如果你需要从视图中显示一个viewcontroller有几种方法,其中一种是这样的:

创建一个viewcontroller,您的父视图位于该视图控制器的委托上

ParentView *view = [ParentView new];
...
view.delegate = self;

然后,在该委托的ParentView调用方法中

- (IBAction)homeButtonPressed:(id)sender {
    [self.delegate buttonPressed];
}

然后,在你的VC工具里面

 -(void)buttonPressed {
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
    ViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"ViewController"];
    [vc setModalPresentationStyle:UIModalPresentationFullScreen];
    [self presentViewController:vc animated:NO completion:NULL];
}

如果你需要在UIView中保留这些代码并避免委托你可以做这样的伎俩(我个人不喜欢它,但它应该工作)

-(void)buttonPressed{
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
    ViewController *vc = [storyboard      instantiateViewControllerWithIdentifier:@"ViewController"];
    [vc setModalPresentationStyle:UIModalPresentationFullScreen];
    [(UIViewController*)self.nextResonder presentViewController:vc animated:NO completion:NULL];
}

Answer 3

这是 Shamsudheen 答案的更惯用的 Swift 3 版本：

extension UIApplication {

    static func topViewController() -> UIViewController? {
        guard var top = shared.keyWindow?.rootViewController else {
            return nil
        }
        while let next = top.presentedViewController {
            top = next
        }
        return top
    } 
}

然后你就可以调用：

UIApplication.topViewController()?.present(...)