Question

我有一个视图控制器使用modalPresentationStyle = UIModalPresentationCustom呈现另一个视图控制器。设置的内容使得呈现视图控制器视图的一部分显示在呈现的视图控制器视图下方。在此状态下，呈现视图控制器仍然可以正确处理自动旋转，并使用自动布局处理呈现的视图控制器的旋转。

我现在正尝试使用iOS 7的自定义视图控制器转换API以交互方式实现解除呈现的视图控制器。它的工作原理除外，当取消交互式解雇时，自动旋转的处理停止工作。（它会在稍后解除显示的视图控制器后再次工作。）为什么会发生这种情况，我该如何解决这个问题？

编辑：以下是您可以运行以演示此问题的代码。从下面弹出一个视图，您可以通过向下滑动来消除它。如果您通过不完全向下滑动来取消解雇，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具有混乱的布局。

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

对于大量的代码转储感到抱歉，但我不知道我做错了什么。以下是正在发生的事情的草图：ViewController1呈现ViewController2。 ViewController1实现UIViewControllerTransitioningDelegate，因此它返回动画/交互式控制器以进行转换。 ViewController2有一个平移手势识别器，可以驱动互动解雇;它实现UIViewControllerInteractiveTransitioning作为解雇的交互式控制器。如果用户将视图拖得足够远，它还会保留对动画控制器的引用以解除转换以完成转换。最后，有两个动画控制器对象。 PresentAnimationController设置autolayout约束以处理呈现的视图控制器视图的旋转，DismissAnimationController完成解雇。

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 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:

注释掉线和所有约束以及addConstraint:调用并且它应该起作用

编辑：

只是在手势被取消时才看到它有效，而不是在最初显示视图时。注释掉除

之外的完成块中的所有内容

[transitionContext completeTransition:YES];

取消呈现的视图控制器的交互式解雇转换后，视图控制器不会自动旋转

1 个答案: