在iOS 13中,模态视图控制器在呈现时有一个新的行为。

现在它不是全屏默认情况下,当我向下滑动时,应用会自动解除视图控制器。

我怎么能防止这种行为,并回到旧的全屏模态vc?

谢谢


当前回答

我在ios 13中使用了swizzling

import Foundation
import UIKit

private func _swizzling(forClass: AnyClass, originalSelector: Selector, swizzledSelector: Selector) {
    if let originalMethod = class_getInstanceMethod(forClass, originalSelector),
       let swizzledMethod = class_getInstanceMethod(forClass, swizzledSelector) {
        method_exchangeImplementations(originalMethod, swizzledMethod)
    }
}

extension UIViewController {

    static let preventPageSheetPresentation: Void = {
        if #available(iOS 13, *) {
            _swizzling(forClass: UIViewController.self,
                       originalSelector: #selector(present(_: animated: completion:)),
                       swizzledSelector: #selector(_swizzledPresent(_: animated: completion:)))
        }
    }()

    @available(iOS 13.0, *)
    @objc private func _swizzledPresent(_ viewControllerToPresent: UIViewController,
                                        animated flag: Bool,
                                        completion: (() -> Void)? = nil) {
        if viewControllerToPresent.modalPresentationStyle == .pageSheet
                   || viewControllerToPresent.modalPresentationStyle == .automatic {
            viewControllerToPresent.modalPresentationStyle = .fullScreen
        }
        _swizzledPresent(viewControllerToPresent, animated: flag, completion: completion)
    }
}

然后放这个

UIViewController.preventPageSheetPresentation

的某个地方

例如在AppDelegate中

func application(_ application: UIApplication,
                 didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]?) -> Bool {

    UIViewController.preventPageSheetPresentation
    // ...
    return true
}

其他回答

我添加的信息可能对某人有用。如果你有任何故事板segue,要回到旧的风格,你需要将kind属性设置为modal Present,并将Presentation属性设置为全屏。

以上的答案和建议是正确的,下面是另一个版本,和有效的方法使用编程。

创建一个UIView扩展

创建一个方法()

//#1
extension UIViewController {

//#2
func presentLocal(_ viewControllerToPresent: UIViewController, animated flag: 
Bool, completion: (() -> Void)? = nil) {

//Reusing below 2 lines :-)
viewControllerToPresent.modalPresentationStyle = .overCurrentContext
self.present(viewControllerToPresent, animated: flag, completion: completion)

  }
}

调用如下所示

let vc = MyViewController()
let nc = UINavigationController(rootViewController: vc)
sourceView.presentLocal(nc, animated: true, completion: nil)

OR

let vc = MyViewController()
sourceView.presentLocal(vc, animated: true, completion: nil)

为UIViewController创建一个类别(比如UIViewController+PresentationStyle)。向其添加以下代码。

 -(UIModalPresentationStyle)modalPresentationStyle{
     return UIModalPresentationStyleFullScreen;
}

设置导航控制器。modalPresentationStyle到。fullscreen已经重复了一千多次了,但让我给你们展示另一个阻止器,它会导致UIViewController / UINavigationController没有在全屏显示,即使所有的属性都设置正确。

对我来说,罪魁祸首就藏在这条线里

navigationController?.presentationController?.delegate = self

显然,当设置UIAdaptivePresentationControllerDelegate时,你需要在可选的delegate方法中指定表示样式

    public func adaptivePresentationStyle(for controller: UIPresentationController) -> UIModalPresentationStyle {
        presentationStyle
    }

这是我在objective - c中使用类别的修复版本。使用这种方法,你将拥有默认的UIModalPresentationStyleFullScreen行为,直到另一个显式设置。

#import "UIViewController+Presentation.h"
#import "objc/runtime.h"

@implementation UIViewController (Presentation)

- (void)setModalPresentationStyle:(UIModalPresentationStyle)modalPresentationStyle {
    [self setPrivateModalPresentationStyle:modalPresentationStyle];
}

-(UIModalPresentationStyle)modalPresentationStyle {
    UIModalPresentationStyle style = [self privateModalPresentationStyle];
    if (style == NSNotFound) {
        return UIModalPresentationFullScreen;
    }
    return style;
}

- (void)setPrivateModalPresentationStyle:(UIModalPresentationStyle)modalPresentationStyle {
    NSNumber *styleNumber = [NSNumber numberWithInteger:modalPresentationStyle];
     objc_setAssociatedObject(self, @selector(privateModalPresentationStyle), styleNumber, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (UIModalPresentationStyle)privateModalPresentationStyle {
    NSNumber *styleNumber = objc_getAssociatedObject(self, @selector(privateModalPresentationStyle));
    if (styleNumber == nil) {
        return NSNotFound;
    }
    return styleNumber.integerValue;
}

@end