取消呈现的视图控制器的交互式解除转换后，视图控制器不会自动旋转

Question

我有一个视图控制器向另一个视图控制器提供modalPresentationStyle = UIModalPresentationCustom。设置了一些东西，以便呈现视图控制器的视图的一部分显示在呈现的视图控制器的视图下方。在这种状态下，呈现视图控制器仍然正确处理自动旋转，我使用自动布局处理呈现视图控制器的旋转。

我现在尝试使用 iOS 7 的自定义视图控制器转换 API 以交互方式关闭呈现的视图控制器。它的工作原理是，当交互式解雇被取消时，自动旋转的处理停止工作。 （稍后关闭呈现的视图控制器后它再次工作。）为什么会发生这种情况，我该如何解决这个问题？

编辑：您可以运行以下代码来演示问题。从下方弹出一个视图，您可以通过向下滑动来关闭它。如果您通过不一直向下滑动来取消关闭，则呈现视图控制器的视图不再响应旋转，并且呈现的视图控制器的视图布局混乱。

编辑：下面是 Xcode 项目的代码链接： https://drive.google.com/file/d/0BwcBqUuDfCG2YlhVWE1QekhUWlk/edit?usp=sharing

对大量代码转储感到抱歉，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，因此它返回了动画/交互式控制器以进行转换。 ViewController2 有一个平移手势识别器，用于驱动交互式解雇；它实现了UIViewControllerInteractiveTransitioning 以作为解除的交互式控制器。如果用户将视图向下拖动得足够远，它还保留对动画控制器的引用以完成过渡。最后，有两个动画控制器对象。 PresentAnimationController 设置自动布局约束以处理呈现的视图控制器视图的旋转，DismissAnimationController 完成解除。

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; 并在您设置的完成块中设置所有约束 - (void)animateTransition:

注释该行和所有约束和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，而不是在最初显示视图时起作用。注释掉完成块中除

之外的所有内容

[transitionContext completeTransition:YES];