Question

我有一个UINavigationController作为我在iOS 7和iOS 8上的UIWindow的根视图控制器。从它的一个视图控制器，我提出了一个具有交叉溶解演示风格的全屏模态视图控制器。这个模态视图控制器应该能够旋转到所有方向，并且它工作正常。

问题是当设备以横向方向保持并且模态视图控制器被解除时。呈现模态的视图控制器仅支持纵向方向，并且我已确认UIInterfaceOrientationMaskPortrait返回到-application：supportedInterfaceOrientationsForWindow：。 -shouldAutorotate也返回YES。然而，在解除模态之后，呈现视图控制器的方向仍然是风景。在允许模态采取设备方向的同时，如何强制它保持纵向方向？我的代码如下：

App代表：

- (NSUInteger)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window
{
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {
        UINavigationController *navigationController = (UINavigationController *)self.deckController.centerController;
        NSArray *viewControllers = [navigationController viewControllers];
        UIViewController *top = [viewControllers lastObject];

        if (top && [top presentedViewController]) {
            UIViewController *presented = [top presentedViewController];
            if ([presented respondsToSelector:@selector(isDismissing)] && ![(id)presented isDismissing]) {
                top = presented;
            }
        }

        return [top supportedInterfaceOrientations];
    }

    return (UIInterfaceOrientationMaskLandscapeLeft|UIInterfaceOrientationMaskLandscapeRight);
}

呈现视图控制器：

- (BOOL)shouldAutorotate {
    return YES;
}

- (NSUInteger)supportedInterfaceOrientations {
    return UIInterfaceOrientationMaskPortrait;
}

- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation {
    return UIInterfaceOrientationPortrait;
}

模态视图控制器：

- (BOOL)shouldAutorotate
{
    return YES;
}

- (NSUInteger)supportedInterfaceOrientations
{
    return (UIInterfaceOrientationMaskLandscape|UIInterfaceOrientationMaskLandscapeLeft|UIInterfaceOrientationMaskPortrait);
}

Answer 1

如果模态控制器在解除之前处于横向方向，则呈现的ViewController可能无法返回到原点方向（纵向）。问题是因为在控制器实际被解除之前调用了AppDelegate supportedInterfaceOrientationsForWindow方法，并且呈现的控制器检查仍然返回Landscape掩码。

设置一个标志，指示是否显示（模态）呈现的视图控制器。

- (void)awakeFromNib // or where you instantiate your ViewController from
{
    [super awakeFromNib];
    self.presented = YES;
}

- (IBAction)exitAction:(id)sender // where you dismiss the modal
{
    self.presented = NO;
    [self dismissViewControllerAnimated:NO completion:nil];
}

在提供的模态中，ViewController根据标志设置方向：当显示模态ViewController时 - 返回Landscape。当它被解雇然后返回肖像

- (NSUInteger)supportedInterfaceOrientations
{
    if ([self isPresented]) {
        return UIInterfaceOrientationMaskLandscape;
    } else {
        return UIInterfaceOrientationMaskPortrait;
    }
}

最后一步 - 从你的AppDelegate调用模态呈现ViewController的方向。我只是检查当前呈现的ViewController并在其上调用supportedInterfaceOrientations

- (NSUInteger)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window
{
    NSUInteger orientationMask = UIInterfaceOrientationMaskPortrait;

    UIViewController *currentVC = self.window.rootViewController.presentedViewController; // gets the presented VC
    orientationMask = [currentVC supportedInterfaceOrientations];

    return orientationMask;
}

有关详情，请查看this link

Answer 2

我最终继承了UINavigationController并重写了它的旋转方法。以下解决方案适用于iOS 7，但我相信iOS 8 beta 5中存在一个错误，导致视图控制器的视图在横向偏移模式后缩小到屏幕高度的一半。

UINavigationController子类：

- (BOOL)shouldAutorotate
{
    return NO;
}

- (NSUInteger)supportedInterfaceOrientations
{
    return UIInterfaceOrientationMaskPortrait;
}

- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation
{
    return UIInterfaceOrientationPortrait;
}

Answer 3

此解决方案适用于iOS 8 +。

问题描述

应用程序密钥窗口将UINavigationController的子类作为其rootViewController。
此NC子类禁止某些界面方向。
NC堆栈中的某些视图控制器（VC1）以模态和全屏方式呈现另一个视图控制器（VC2）。
这个呈现的VC2允许比NC更多的接口方向。
用户将设备旋转到NC禁止的方向，但是由VC2提供。
用户驳回提供的VC2。
VC1的视图框架不正确。

设置和插图

UINavigationController的子类：

- (NSUInteger)supportedInterfaceOrientations
{
    return UIInterfaceOrientationMaskPortrait;
}

- (BOOL)shouldAutorotate
{
    return YES;
}

VC1初始外观和UI视图堆栈：

Initial appearance

从VC1：

QLPreviewController *pc = [[QLPreviewController alloc] init];
pc.dataSource = self;
pc.delegate = self;
pc.modalPresentationStyle = UIModalPresentationFullScreen;
[self.navigationController presentViewController:pc animated:YES completion:nil];

显示VC2并将设备旋转为横向：

Presented and rotated

VC2被解雇，设备重新进入纵向模式，但NC堆栈仍处于横向状态：

VC2 dismissed

原因

Apple文档声明：

使用presentViewController：animated：completion：方法呈现视图控制器时，UIKit始终管理演示过程。该过程的一部分涉及创建适合给定演示样式的演示控制器。

显然处理UINavigationController堆栈时存在错误。

解决方案

可以通过提供我们自己的转换委托来绕过此错误。

BTTransitioningDelegate.h

#import <UIKit/UIKit.h>

@interface BTTransitioningDelegate : NSObject <UIViewControllerTransitioningDelegate>

@end

BTTransitioningDelegate.m

#import "BTTransitioningDelegate.h"

static NSTimeInterval kDuration = 0.5;

// This class handles presentation phase.
@interface BTPresentedAC : NSObject <UIViewControllerAnimatedTransitioning>

@end

@implementation BTPresentedAC

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

- (void)animateTransition:(id<UIViewControllerContextTransitioning>)context
{
    // presented VC
    UIViewController *toVC = [context viewControllerForKey:UITransitionContextToViewControllerKey];

    // presented controller ought to be fullscreen
    CGRect frame = [[[UIApplication sharedApplication] keyWindow] bounds];
    // we will slide view of the presended VC from the bottom of the screen,
    // so here we set the initial frame
    toVC.view.frame = CGRectMake(frame.origin.x, frame.origin.y + frame.size.height, frame.size.width, frame.size.height);

    // [context containerView] acts as the superview for the views involved in the transition
    [[context containerView] addSubview:toVC.view];

    UIViewAnimationOptions options = (UIViewAnimationOptionCurveEaseOut);

    [UIView animateWithDuration:kDuration delay:0 options:options animations:^{
        // slide view to position
        toVC.view.frame = frame;
    } completion:^(BOOL finished) {
        // required to notify the system that the transition animation is done
        [context completeTransition:finished];
    }];
}

@end


// This class handles dismission phase.
@interface BTDismissedAC : NSObject <UIViewControllerAnimatedTransitioning>

@end

@implementation BTDismissedAC

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

- (void)animateTransition:(id<UIViewControllerContextTransitioning>)context
{
    // presented VC
    UIViewController *fromVC = [context viewControllerForKey:UITransitionContextFromViewControllerKey];
    // presenting VC
    UIViewController *toVC = [context viewControllerForKey:UITransitionContextToViewControllerKey];

    // inserting presenting VC's view under presented VC's view
    toVC.view.frame = [[[UIApplication sharedApplication] keyWindow] bounds];
    [[context containerView] insertSubview:toVC.view belowSubview:fromVC.view];

    // current frame and transform of presented VC
    CGRect frame = fromVC.view.frame;
    CGAffineTransform transform = fromVC.view.transform;

    // determine current presented VC's view rotation and assemble
    // target frame to provide naturally-looking dismissal animation
    if (transform.b == -1) {
        // -pi/2
        frame = CGRectMake(frame.origin.x + frame.size.width, frame.origin.y, frame.size.width, frame.size.height);
    } else if (transform.b == 1) {
        // pi/2
        frame = CGRectMake(frame.origin.x - frame.size.width, frame.origin.y, frame.size.width, frame.size.height);
    } else if (transform.a == -1) {
        // pi
        frame = CGRectMake(frame.origin.x, frame.origin.y - frame.size.height, frame.size.width, frame.size.height);
    } else {
        // 0
        frame = CGRectMake(frame.origin.x, frame.origin.y + frame.size.height, frame.size.width, frame.size.height);
    }

    UIViewAnimationOptions options = (UIViewAnimationOptionCurveEaseOut);

    [UIView animateWithDuration:kDuration delay:0 options:options animations:^{
        // slide view off-screen
        fromVC.view.frame = frame;
    } completion:^(BOOL finished) {
        // required to notify the system that the transition animation is done
        [context completeTransition:finished];
    }];
}

@end


@implementation BTTransitioningDelegate

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

- (id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed
{
    return [[BTDismissedAC alloc] init];
}

@end

在呈现VC时导入转换委托：

#import "BTTransitioningDelegate.h"

存储对实例的强引用：

@property (nonatomic, strong) BTTransitioningDelegate *transitioningDelegate;

-viewDidLoad实例化：

self.transitioningDelegate = [[BTTransitioningDelegate alloc] init];

适当时打电话：

QLPreviewController *pc = [[QLPreviewController alloc] init];
pc.dataSource = self;
pc.delegate = self;
pc.transitioningDelegate = self.transitioningDelegate;
pc.modalPresentationStyle = UIModalPresentationFullScreen;

[self.navigationController presentViewController:pc animated:YES completion:nil];

iOS 7+关闭模态视图控制器和强制纵向方向

3 个答案:

问题描述

设置和插图

原因

解决方案