如何创建一个将在iPad上使用popover并推送到iPhone上的导航堆栈的segue？

Question

在我的应用程序中,某些视图控制器在iPad上(或者更具体地说,是一个常规的水平尺寸类)将它们作为弹出窗口显示是有意义的,但是在iPhone(或紧凑的水平尺寸类)上推送它是有意义的他们到导航堆栈上.有一种优雅的方式来支持这个吗？默认情况下,如果我使用"Present as Popover"segue,它将在iPhone上以模态方式显示,这不是我想要的.

我找到了一种方法来获得我想要的行为,但它很难看,而且容易出错.我根据我目前所处的大小类选择两个不同的segue.为了支持iOS 9多任务,我实现[UIViewController willTransitionToTraitCollection:withTransitionCoordinator]并在弹出窗口和导航控制器之间手动移动视图控制器(这部分看起来特别容易出错).

似乎应该有一些简单的方法来实现自定义segue来处理这个,或者某种自定义自适应表示控制器,但我还是无法绕过它.有人做过这样的成功吗？

Answer 1

这就是我最终构建的。我对此不太满意，这就是为什么我直到现在才发布它。它不支持两个 segues 来查看具有相同类的控制器，并且它要求您自己跟踪弹出窗口的源矩形和源视图。但也许对其他人来说这将是一个很好的起点。

PushPopoverSegue.swift

import UIKit

class PushPopoverSegue: UIStoryboardSegue {

    var sourceBarButtonItem: UIBarButtonItem!
    var permittedArrowDirections: UIPopoverArrowDirection = .Any

    override func perform() {
        assert( self.sourceViewController.navigationController != nil )
        assert( self.sourceBarButtonItem != nil )

        if self.sourceViewController.traitCollection.horizontalSizeClass == .Compact {
            self.sourceViewController.navigationController!.pushViewController(self.destinationViewController, animated: true)
        }
        else {
            let navigationController = UINavigationController(rootViewController: self.destinationViewController)
            let popover = UIPopoverController(contentViewController: navigationController)
            popover.presentPopoverFromBarButtonItem(self.sourceBarButtonItem, permittedArrowDirections: self.permittedArrowDirections, animated: true)
        }
    }

}

UIViewController+PushPopoverTransition.h

#import <UIKit/UIKit.h>

@interface UIViewController (PushPopoverTransition)

- (void) transitionPushPopoversToHorizontalSizeClass: (UIUserInterfaceSizeClass) sizeClass withMapping: (NSDictionary*) mapping;

@end

UIViewController+PushPopoverTransition.m

#import "UIViewController+PushPopoverTransition.h"

@implementation UIViewController (PushPopoverTransition)

- (void) transitionPushPopoversToHorizontalSizeClass: (UIUserInterfaceSizeClass) sizeClass withMapping: (NSDictionary*) mapping
{
    if ( sizeClass == UIUserInterfaceSizeClassCompact )
    {
        if ( self.presentedViewController == nil )
            return;

        NSParameterAssert( [self.presentedViewController isKindOfClass:[UINavigationController class]] );
        UINavigationController* navigationController = (UINavigationController*) self.presentedViewController;
        NSArray* viewControllers = navigationController.viewControllers;
        UIViewController* topOfStack = viewControllers[0];

        if ( [mapping.allKeys containsObject:NSStringFromClass( [topOfStack class] ) ] )
        {
            [self.presentedViewController dismissViewControllerAnimated:NO completion:^{
                for ( UIViewController* viewController in viewControllers )
                    [self.navigationController pushViewController:viewController animated:NO];
            }];
        }
    }
    else if ( sizeClass == UIUserInterfaceSizeClassRegular )
    {
        NSUInteger indexOfSelf = [self.navigationController.viewControllers indexOfObject:self];

        if ( indexOfSelf < self.navigationController.viewControllers.count  - 1 )
        {
            UIViewController* topOfStack = self.navigationController.viewControllers[indexOfSelf + 1];
            if ( [mapping.allKeys containsObject:NSStringFromClass( [topOfStack class] )] )
            {
                NSArray* poppedControllers = [self.navigationController popToViewController:self animated:NO];
                UINavigationController* navigationController = [[UINavigationController alloc] init];
                navigationController.modalPresentationStyle = UIModalPresentationPopover;
                navigationController.viewControllers = poppedControllers;

                id popoverSource = mapping[NSStringFromClass( [topOfStack class] )];
                if ( [popoverSource isKindOfClass:[UIBarButtonItem class]] )
                {
                    navigationController.popoverPresentationController.barButtonItem = popoverSource;
                }
                else if ( [popoverSource isKindOfClass:[NSArray class]] )
                {
                    NSArray* popoverSourceArray = (NSArray*) popoverSource;
                    NSParameterAssert(popoverSourceArray.count == 2);
                    UIView* sourceView = popoverSourceArray[0];
                    CGRect sourceRect = [(NSValue*) popoverSourceArray[1] CGRectValue];
                    navigationController.popoverPresentationController.sourceView = sourceView;
                    navigationController.popoverPresentationController.sourceRect = sourceRect;
                }

                [self presentViewController:navigationController animated:NO completion:nil];
            }
        }
    }
}

@end

用法示例

在界面生成器中创建一个segue，并将其“Kind”设置为“Custom”，将“Class”设置为PushPopoverSegue.

视图控制器.m

- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    ((PushPopoverSegue*) segue).sourceView = /* source view */;
    ((PushPopoverSegue*) segue).sourceRect = /* source rect */;
}

-(void) willTransitionToTraitCollection:(UITraitCollection *)newCollection withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator
{
    if ( newCollection.horizontalSizeClass == UIUserInterfaceSizeClassUnspecified )
        return;

    [self transitionPushPopoversToHorizontalSizeClass:newCollection.horizontalSizeClass withMapping:@{
        @"MyDestinationViewController": @[ /* source view */,
                                       [NSValue valueWithCGRect:/* source rect*/] ]
    }];
}