ios - 取消呈现的 View Controller 的交互式关闭转换后， View Controller 不会自动旋转

Question

我有一个 View Controller ，使用 modalPresentationStyle = UIModalPresentationCustom 呈现另一个 View Controller 。事物的设置使得呈现 View Controller 的 View 的一部分显示在呈现 View Controller 的 View 下方。在这种状态下，呈现 View Controller 仍然正确处理自动旋转，我使用自动布局处理呈现 View Controller 的旋转。

我现在正在尝试使用 iOS 7 的自定义 View Controller 转换 API 以交互方式关闭呈现的 View Controller 。它的工作原理是，当交互式关闭被取消时，自动旋转的处理停止工作。 (它在呈现的 View Controller 稍后被关闭后再次工作。)为什么会发生这种情况，我该如何解决这个问题？

编辑:这是您可以运行以演示问题的代码。从下方弹出一个 View ，您可以通过向下滑动将其关闭。如果您通过不一直向下滑动来取消取消，则呈现 View Controller 的 View 将不再响应旋转，并且呈现 View Controller 的 View 布局困惑。

编辑:这是作为 Xcode 项目的以下代码的链接: https://drive.google.com/file/d/0BwcBqUuDfCG2YlhVWE1QekhUWlk/edit?usp=sharing

对于大量代码转储，我深表歉意，但我不知道我做错了什么。这是正在发生的事情的草图:ViewController1 呈现 ViewController2。 ViewController1 实现了 UIViewControllerTransitioningDelegate，因此它返回过渡的动画/交互 Controller 。 ViewController2 有一个平移手势识别器，可以驱动交互式关闭；它实现了 UIViewControllerInteractiveTransitioning 来充当解雇的交互式 Controller 。它还保留对动画 Controller 的引用，以便在用户将 View 向下拖动得足够远时关闭以完成过渡。最后，有两个动画 Controller 对象。 PresentAnimationController 设置自动布局约束来处理呈现的 View Controller View 的旋转，DismissAnimationController 完成关闭。

ViewController1.h

#import <UIKit/UIKit.h>

@interface ViewController1 : UIViewController <UIViewControllerTransitioningDelegate>

@end

ViewController1.m

#import "ViewController1.h"

#import "ViewController2.h"

#import "PresentAnimationController.h"
#import "DismissAnimationController.h"

@implementation ViewController1

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        self.title = @"View 1";

        self.navigationItem.prompt = @"Press “Present” and then swipe down to dismiss.";
        self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Present" style:UIBarButtonItemStylePlain target:self action:@selector(pressedPresentButton:)];
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.view.backgroundColor = [UIColor whiteColor];

    // Some subview just to check if layout is working.
    UIView * someSubview = [[UIView alloc] initWithFrame:self.view.bounds];
    someSubview.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    someSubview.backgroundColor = [UIColor orangeColor];
    someSubview.layer.borderColor = [UIColor redColor].CGColor;
    someSubview.layer.borderWidth = 2;
    [self.view addSubview:someSubview];
}

// --------------------

- (void)pressedPresentButton:(id)sender
{
    ViewController2 * presentedVC = [[ViewController2 alloc] initWithNibName:nil bundle:nil];

    presentedVC.modalPresentationStyle = UIModalPresentationCustom;
    presentedVC.transitioningDelegate = self;

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

// --------------------

// View Controller Transitioning Delegate Methods.

- (id <UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source
{
    return [[PresentAnimationController alloc] init];;
}

- (id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed
{
    DismissAnimationController * animationController = [[DismissAnimationController alloc] init];

    ViewController2 * presentedVC = (ViewController2 *)self.presentedViewController;

    if (presentedVC.dismissalIsInteractive) {
        presentedVC.dismissAnimationController = animationController;
    }

    return animationController;
}

- (id <UIViewControllerInteractiveTransitioning>)interactionControllerForPresentation:(id <UIViewControllerAnimatedTransitioning>)animator
{
    return nil;
}

- (id <UIViewControllerInteractiveTransitioning>)interactionControllerForDismissal:(id <UIViewControllerAnimatedTransitioning>)animator
{
    ViewController2 * presentedVC = (ViewController2 *)self.presentedViewController;

    if (presentedVC.dismissalIsInteractive) {
        return presentedVC;
    }
    else {
        return nil;
    }
}

@end

ViewController2.h

#import <UIKit/UIKit.h>

#import "DismissAnimationController.h"

@interface ViewController2 : UIViewController <UIViewControllerInteractiveTransitioning>

@property (weak, nonatomic) UIView * contentView;

@property (nonatomic, readonly) BOOL dismissalIsInteractive;
@property (strong, nonatomic) DismissAnimationController * dismissAnimationController;

@end

ViewController2.m

#import "ViewController2.h"

@interface ViewController2 ()

@property (strong, nonatomic) id<UIViewControllerContextTransitioning> transitionContext;

@end

@implementation ViewController2

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        _dismissalIsInteractive = NO;
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.view.backgroundColor = [UIColor colorWithWhite:0 alpha:0.5];

    // Set up content view.
    CGRect frame = UIEdgeInsetsInsetRect(self.view.bounds, UIEdgeInsetsMake(15, 15, 15, 15));
    UIView * contentView = [[UIView alloc] initWithFrame:frame];
    self.contentView = contentView;
    contentView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    contentView.backgroundColor = [UIColor cyanColor];
    contentView.layer.borderColor = [UIColor blueColor].CGColor;
    contentView.layer.borderWidth = 2;
    [self.view addSubview:contentView];

    // Set up pan dismissal gesture recognizer.
    UIPanGestureRecognizer * panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(dismissalPan:)];
    [self.view addGestureRecognizer:panGesture];
}

// --------------------

- (void)dismissalPan:(UIPanGestureRecognizer *)panGesture
{
    switch (panGesture.state) {
        case UIGestureRecognizerStateBegan: {
            _dismissalIsInteractive = YES;

            [self.presentingViewController dismissViewControllerAnimated:YES completion:nil];

            break;
        }

        case UIGestureRecognizerStateChanged: {
            CGPoint translation = [panGesture translationInView:self.view];

            CGFloat percent;
            if (translation.y > 0) {
                percent = translation.y / self.view.bounds.size.height;
                percent = MIN(percent, 1.0);
            }
            else {
                percent = 0;
            }

            // Swiping content view down.
            CGPoint center;
            center.x = CGRectGetMidX(self.view.bounds);
            center.y = CGRectGetMidY(self.view.bounds);
            if (translation.y > 0) {
                center.y += translation.y;  // Only allow swiping down.
            }
            self.contentView.center = center;

            self.view.backgroundColor = [UIColor colorWithWhite:0 alpha:(0.5 * (1.0 - percent))];

            [self.transitionContext updateInteractiveTransition:percent];

            break;
        }

        case UIGestureRecognizerStateEnded: // Fall through.
        case UIGestureRecognizerStateCancelled: {
            _dismissalIsInteractive = NO;

            id<UIViewControllerContextTransitioning> transitionContext = self.transitionContext;
            self.transitionContext = nil;

            DismissAnimationController * dismissAnimationController = self.dismissAnimationController;
            self.dismissAnimationController = nil;

            CGPoint translation = [panGesture translationInView:self.view];

            if (translation.y > 100) {
                // Complete dismissal.

                [dismissAnimationController animateTransition:transitionContext];
            }
            else {
                // Cancel dismissal.

                void (^animations)() = ^() {
                    CGPoint center;
                    center.x = CGRectGetMidX(self.view.bounds);
                    center.y = CGRectGetMidY(self.view.bounds);
                    self.contentView.center = center;

                    self.view.backgroundColor = [UIColor colorWithWhite:0 alpha:0.5];
                };
                void (^completion)(BOOL) = ^(BOOL finished) {
                    [transitionContext cancelInteractiveTransition];
                    [transitionContext completeTransition:NO];
                };
                [UIView animateWithDuration:0.5 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:animations completion:completion];
            }

            break;
        }

        default: {

            break;
        }
    }
}

// --------------------

// View Controller Interactive Transitioning Methods.

- (void)startInteractiveTransition:(id<UIViewControllerContextTransitioning>)transitionContext
{
    self.transitionContext = transitionContext;
}

@end

PresentAnimationController.h

#import <Foundation/Foundation.h>

@interface PresentAnimationController : NSObject <UIViewControllerAnimatedTransitioning>

@end

PresentAnimationController.m

#import "PresentAnimationController.h"

#import "ViewController2.h"

@implementation PresentAnimationController

- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
    UIViewController * fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    ViewController2 * toVC = (ViewController2 *)[transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

    UIView * containerView = [transitionContext containerView];

    CGPoint toCenter = fromVC.view.center;
    CGRect toBounds = fromVC.view.bounds;

    toVC.view.center = toCenter;
    toVC.view.bounds = toBounds;
    [toVC.view layoutIfNeeded];

    [containerView addSubview:fromVC.view];
    [containerView addSubview:toVC.view];

    CGRect contentViewEndFrame = toVC.contentView.frame;

    CGRect contentViewStartFrame = contentViewEndFrame;
    contentViewStartFrame.origin.y += contentViewStartFrame.size.height;
    toVC.contentView.frame = contentViewStartFrame;

    UIColor * endBackgroundColor = toVC.view.backgroundColor;

    toVC.view.backgroundColor = [UIColor clearColor];

    void (^animations)() = ^() {
        toVC.contentView.frame = contentViewEndFrame;

        toVC.view.backgroundColor = endBackgroundColor;
    };
    void (^completion)(BOOL) = ^(BOOL finished) {
        toVC.view.autoresizingMask = UIViewAutoresizingNone;

        toVC.view.translatesAutoresizingMaskIntoConstraints = NO;

        NSLayoutConstraint * centerXConstraint = [NSLayoutConstraint constraintWithItem:toVC.view
                                                                              attribute:NSLayoutAttributeCenterX
                                                                              relatedBy:NSLayoutRelationEqual
                                                                                 toItem:fromVC.view
                                                                              attribute:NSLayoutAttributeCenterX
                                                                             multiplier:1
                                                                               constant:0];
        NSLayoutConstraint * centerYConstraint = [NSLayoutConstraint constraintWithItem:toVC.view
                                                                              attribute:NSLayoutAttributeCenterY
                                                                              relatedBy:NSLayoutRelationEqual
                                                                                 toItem:fromVC.view
                                                                              attribute:NSLayoutAttributeCenterY
                                                                             multiplier:1
                                                                               constant:0];
        NSLayoutConstraint * widthConstraint = [NSLayoutConstraint constraintWithItem:toVC.view
                                                                            attribute:NSLayoutAttributeWidth
                                                                            relatedBy:NSLayoutRelationEqual
                                                                               toItem:fromVC.view
                                                                            attribute:NSLayoutAttributeWidth
                                                                           multiplier:1
                                                                             constant:0];
        NSLayoutConstraint * heightConstraint = [NSLayoutConstraint constraintWithItem:toVC.view
                                                                             attribute:NSLayoutAttributeHeight
                                                                             relatedBy:NSLayoutRelationEqual
                                                                                toItem:fromVC.view
                                                                             attribute:NSLayoutAttributeHeight
                                                                            multiplier:1
                                                                              constant:0];
        [containerView addConstraint:centerXConstraint];
        [containerView addConstraint:centerYConstraint];
        [containerView addConstraint:widthConstraint];
        [containerView addConstraint:heightConstraint];

        [transitionContext completeTransition:YES];
    };
    [UIView animateWithDuration:0.5 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:animations completion:completion];
}

- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
{
    return 0.5;
}

@end

DismissAnimationController.h

#import <Foundation/Foundation.h>

@interface DismissAnimationController : NSObject <UIViewControllerAnimatedTransitioning>

@end

DismissAnimationController.m

#import "DismissAnimationController.h"

#import "ViewController2.h"

@implementation DismissAnimationController

- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
    ViewController2 * fromVC = (ViewController2 *)[transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    UIViewController * toVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

    UIView * containerView = [transitionContext containerView];

    [containerView addSubview:toVC.view];
    [containerView addSubview:fromVC.view];

    void (^animations)() = ^() {
        CGRect contentViewEndFrame = fromVC.contentView.frame;
        contentViewEndFrame.origin.y = CGRectGetMaxY(fromVC.view.bounds) + 15;
        fromVC.contentView.frame = contentViewEndFrame;

        fromVC.view.backgroundColor = [UIColor clearColor];
    };
    void (^completion)(BOOL) = ^(BOOL finished) {
        if ([transitionContext isInteractive]) {
            [transitionContext finishInteractiveTransition];
        }

        [transitionContext completeTransition:YES];
    };
    [UIView animateWithDuration:0.5 delay:0 options:UIViewAnimationOptionCurveLinear animations:animations completion:completion];
}

- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
{
    return 0.5;
}

@end

AppDelegate.m

#import "AppDelegate.h"

#import "ViewController1.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

    ViewController1 * vc = [[ViewController1 alloc] initWithNibName:nil bundle:nil];
    UINavigationController * nav = [[UINavigationController alloc] initWithRootViewController:vc];
    self.window.rootViewController = nav;

    [self.window makeKeyAndVisible];
    return YES;
}

@end

Answer 1

我想我发现了你的问题。在您的 PresentAnimationController.m 中指定 toVC.view.translatesAutoresizingMaskIntoConstraints = NO; 并在您设置的完成 block 中设置所有约束- (void)animateTransition:

注释该行和所有约束以及 addConstraint: 调用，它应该可以工作

编辑:

刚刚看到它仅在取消手势时起作用，而不是在最初显示 View 时起作用。注释掉完成 block 中的所有内容，除了

[transitionContext completeTransition:YES];