iOS 6 : Parent modal's modalPresentationStyle ignored after rotation

Question

对于 iOS6 的 iPad，我们有一个错误，模态视图 Controller 将扩展到全屏，即使它被告知使用“表单”演示文稿样式。但是，只有当有两个模态，一个父模态和它的子模态时，才会发生这种情况。

这就是第一个模态框的创建和呈现方式:

UINavigationController *navigationController = [[[UINavigationController alloc] initWithRootViewController:controller] autorelease];
navigationController.modalPresentationStyle = UIModalPresentationFormSheet;
[parentController presentModalViewController:navigationController animated:YES];
// parentController is my application's root controller

子模态是这样创建和呈现的:

UINavigationController *navigationController = [[[UINavigationController alloc] initWithRootViewController:controller] autorelease];
navigationController.modalPresentationStyle = UIModalPresentationFormSheet;
[parentController presentModalViewController:navigationController animated:YES];
// parentController is the navigationController from above

因此，当从横向旋转到纵向时，父模态将扩展到全屏并保持这种状态，即使我们旋转回横向也是如此。

当我们只有父模态(没有子模态)时，它会按预期工作，即它保持表单样式。

请注意，这种情况只发生在 iOS6(设备和模拟器)上，不会发生在 iOS 5(模拟器，测试人员报告它可以工作)上。

到目前为止，我已经尝试了以下但没有成功:

• 将wantsFullScreenLayout设置为NO
• 强制 wantsFullScreenLayout 通过覆盖它总是返回 NO
• 确保我的导航 Controller 内的 Controller 也指定 UIModalPresentationFormSheet
• 实现preferredInterfaceOrientationForPresentation
• 升级到 iOS 6.0.1

谢谢!

---

更新:因此，我调整了 Apple 开发者论坛 ( https://devforums.apple.com/message/748486#748486 ) 的回复，使其适用于多个嵌套模式。

- (BOOL) needNestedModalHack {
    return [UIDevice currentDevice].systemVersion.floatValue >= 6;
}

- (void) willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation
                                          duration:(NSTimeInterval)duration {

    // We are the top modal, make to sure that parent modals use our size
    if (self.needNestedModalHack && self.presentedViewController == nil && self.presentingViewController) {
        for (UIViewController* parent = self.presentingViewController;
             parent.presentingViewController;
             parent = parent.presentingViewController) {
            parent.view.superview.frame = parent.presentedViewController.view.superview.frame;
        }
    }

    [super willAnimateRotationToInterfaceOrientation:toInterfaceOrientation duration:duration];
}

- (void) willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation
                                 duration:(NSTimeInterval)duration {
    // We are the top modal, make to sure that parent modals are hidden during transition
    if (self.needNestedModalHack && self.presentedViewController == nil && self.presentingViewController) {
        for (UIViewController* parent = self.presentingViewController;
             parent.presentingViewController;
             parent = parent.presentingViewController) {
            parent.view.superview.hidden = YES;
        }
    }

    [super willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];
}

- (void) didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
    // We are the top modal, make to sure that parent modals are shown after animation
    if (self.needNestedModalHack && self.presentedViewController == nil && self.presentingViewController) {
        for (UIViewController* parent = self.presentingViewController;
             parent.presentingViewController;
             parent = parent.presentingViewController) {
            parent.view.superview.hidden = NO;
        }
    }

    [super didRotateFromInterfaceOrientation:fromInterfaceOrientation];
}

Answer 1

不确定这是否应该被视为一个错误，我很好奇 iOS 7 会带来什么，但此问题的当前解决方法是将 modalPresentationStyle 设置为 child-viewController 的 UIModalPresentationCurrentContext。

Set modalPresentationStyle = UIModalPresentationCurrentContext

这使得子项仍然显示为 FormSheet，但阻止父项在旋转时调整为全屏。

德克