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在我的应用程序中，有某些视图控制器在 iPad（或者更具体地说，常规水平尺寸类）上将它们呈现为弹出框是有意义的，但在 iPhone（或紧凑的水平尺寸类）上推送是有意义的将它们放到导航堆栈上。有没有一种优雅的方式来支持这一点？默认情况下，如果我使用“Present as Popover”segue，它将在 iPhone 上模态显示，这不是我想要的。

我找到了一种方法来获得我想要的行为，但它很丑陋并且似乎容易出错。我根据我目前所处的大小类别在两种不同的 segue 之间进行选择。为了支持 iOS 9 多任务处理，我实现[UIViewController willTransitionToTraitCollection:withTransitionCoordinator]并在弹出框和导航控制器之间手动移动视图控制器（这部分似乎特别容易出错）。

似乎应该有一些简单的方法来实现自定义 segue 来处理这个问题，或者某种自定义自适应演示控制器，但我一直无法理解它。有没有人成功做到这一点？

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2 回答 2

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在我看来，这是最简单的方法，

第 1 步：从一个控制器到另一个控制器创建两个 segue。
步骤 2：设置一个 segue 的 segue 属性以推送和弹出另一个segue
步骤 3：现在根据您的要求调用 perform segue，即 iPad 或 iPhone

这是一个示例代码

示例代码 注意：将 bool 条件更改为 false 以检查didSelectRowAtIndexPath.

于 2015-08-28T13:01:13.937 回答
1

这就是我最终构建的内容。我对它不太满意，这就是为什么我直到现在才发布它。它不支持两个 segue 去查看具有相同类的控制器，并且它需要您自己跟踪弹出框的源 rect 和源视图。但也许这对其他人来说是一个很好的起点。

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

示例用法

在界面生成器中创建一个 segue，并将其“种类”设置为自定义，并将其“类”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*/] ]
    }];
}
于 2016-02-07T04:10:45.353 回答