像Instagram iPhone应用程序一样向右滑动导航弹出视图.我如何实现这一目标？

Question

我想在屏幕上向右滑动时弹出一个视图,或者它像导航栏的后退按钮一样工作.

我在用:

self.navigationController.interactivePopGestureRecognizer.delegate = (id<UIGestureRecognizerDelegate>)self;

这个单行代码用于流行导航视图,它对我来说很有用,但是当我在屏幕中间滑动时,这将无法像Instagram iPhone应用程序那样工作.

在这里,我给出了一个Instagram应用程序的屏幕,你可以看到滑动右侧弹出导航视图的示例:

Answer 1

Apple自动实现"刷卡直播VC"仅适用于屏幕左侧~20点.这样,他们确保他们不会弄乱您的应用程序的功能.想象一下,你有一个UIScrollView屏幕,你不能向右滑动,因为它不断弹出VC.这不会很好.

Apple 在这里说:

interactivePopGestureRecognizer

手势识别器负责将顶视图控制器弹出导航堆栈.(只读)

@property(非原子,只读)UIGestureRecognizer*interactivePopGestureRecognizer

导航控制器在其视图上安装此手势识别器,并使用它将最顶层的视图控制器弹出导航堆栈.您可以使用此属性检索手势识别器,并将其与用户界面中其他手势识别器的行为联系起来.将手势识别器绑在一起时,请确保他们同时识别手势,以确保您的手势识别器有机会处理事件.

所以你必须实现自己的UIGestureRecognizer,并将其行为与interactivePopGestureRecognizer你的行为联系起来UIViewController.

编辑:

这是我建立的解决方案.您可以实现符合UIViewControllerAnimatedTransitioning委托的自己的转换.此解决方案有效,但尚未经过全面测试.

您将获得一个交互式滑动过渡以弹出ViewControllers.您可以从视图中的任何位置向右滑动.

已知问题:如果启动平移并在视图宽度的一半之前停止,则转换将被取消(预期行为).在此过程中,视图将重置为其原始帧.在这个动画中,它们是一个视觉故障.

示例的类如下:

UINavigationController> ViewController> SecondViewController

CustomPopTr​​ansition.h:

#import <Foundation/Foundation.h>

@interface CustomPopTransition : NSObject <UIViewControllerAnimatedTransitioning>

@end

CustomPopTr​​ansition.m:

#import "CustomPopTransition.h"
#import "SecondViewController.h"
#import "ViewController.h"

@implementation CustomPopTransition

- (NSTimeInterval)transitionDuration:(id<UIViewControllerContextTransitioning>)transitionContext {
    return 0.3;
}

- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext {

    SecondViewController *fromViewController = (SecondViewController*)[transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    ViewController *toViewController = (ViewController*)[transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

    UIView *containerView = [transitionContext containerView];
    [containerView addSubview:toViewController.view];
    [containerView bringSubviewToFront:fromViewController.view];

    // Setup the initial view states
    toViewController.view.frame = [transitionContext finalFrameForViewController:toViewController];

    [UIView animateWithDuration:0.3 animations:^{

        fromViewController.view.frame = CGRectMake(toViewController.view.frame.size.width, fromViewController.view.frame.origin.y, fromViewController.view.frame.size.width, fromViewController.view.frame.size.height);

    } completion:^(BOOL finished) {

        // Declare that we've finished
        [transitionContext completeTransition:!transitionContext.transitionWasCancelled];
    }];

}

@end

SecondViewController.h:

#import <UIKit/UIKit.h>

@interface SecondViewController : UIViewController <UINavigationControllerDelegate>

@end

SecondViewController.m:

#import "SecondViewController.h"
#import "ViewController.h"
#import "CustomPopTransition.h"

@interface SecondViewController ()

@property (nonatomic, strong) UIPercentDrivenInteractiveTransition *interactivePopTransition;

@end

@implementation SecondViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.navigationController.delegate = self;

    UIPanGestureRecognizer *popRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePopRecognizer:)];
    [self.view addGestureRecognizer:popRecognizer];
}

-(void)viewDidDisappear:(BOOL)animated {

    [super viewDidDisappear:animated];

    // Stop being the navigation controller's delegate
    if (self.navigationController.delegate == self) {
        self.navigationController.delegate = nil;
    }
}

- (id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController *)fromVC toViewController:(UIViewController *)toVC {

    // Check if we're transitioning from this view controller to a DSLSecondViewController
    if (fromVC == self && [toVC isKindOfClass:[ViewController class]]) {
        return [[CustomPopTransition alloc] init];
    }
    else {
        return nil;
    }
}

- (id<UIViewControllerInteractiveTransitioning>)navigationController:(UINavigationController *)navigationController interactionControllerForAnimationController:(id<UIViewControllerAnimatedTransitioning>)animationController {

    // Check if this is for our custom transition
    if ([animationController isKindOfClass:[CustomPopTransition class]]) {
        return self.interactivePopTransition;
    }
    else {
        return nil;
    }
}

- (void)handlePopRecognizer:(UIPanGestureRecognizer*)recognizer {

    // Calculate how far the user has dragged across the view
    CGFloat progress = [recognizer translationInView:self.view].x / (self.view.bounds.size.width * 1.0);
    progress = MIN(1.0, MAX(0.0, progress));

    if (recognizer.state == UIGestureRecognizerStateBegan) {
        NSLog(@"began");
        // Create a interactive transition and pop the view controller
        self.interactivePopTransition = [[UIPercentDrivenInteractiveTransition alloc] init];
        [self.navigationController popViewControllerAnimated:YES];
    }
    else if (recognizer.state == UIGestureRecognizerStateChanged) {
        NSLog(@"changed");
        // Update the interactive transition's progress
        [self.interactivePopTransition updateInteractiveTransition:progress];
    }
    else if (recognizer.state == UIGestureRecognizerStateEnded || recognizer.state == UIGestureRecognizerStateCancelled) {
        NSLog(@"ended/cancelled");
        // Finish or cancel the interactive transition
        if (progress > 0.5) {
            [self.interactivePopTransition finishInteractiveTransition];
        }
        else {
            [self.interactivePopTransition cancelInteractiveTransition];
        }

        self.interactivePopTransition = nil;
    }
}

@end

Answer 2

创建平移手势识别器并移动交互式流行手势识别器的目标。

将您的识别器添加到推送的视图控制器的 viewDidLoad 中，瞧！

let popGestureRecognizer = self.navigationController!.interactivePopGestureRecognizer!
if let targets = popGestureRecognizer.value(forKey: "targets") as? NSMutableArray {
  let gestureRecognizer = UIPanGestureRecognizer()
  gestureRecognizer.setValue(targets, forKey: "targets")
  self.view.addGestureRecognizer(gestureRecognizer)
}

Answer 3

这是一个Swift版本的Spynet的答案,只有一些修改.首先,我为UIView动画定义了一条线性曲线.其次,我在下面的视图中添加了一个半透明的黑色背景,以获得更好的效果.第三,我已经分组了一个UINavigationController.这允许将转换应用于UINavigationController中的任何"Pop"转换.这是代码:

CustomPopTr​​ansition.swift

import UIKit

class CustomPopTransition: NSObject, UIViewControllerAnimatedTransitioning {

    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.3
    }

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        guard let fromViewController = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from),
            let toViewController = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to)
            else {
                return
        }

        let containerView = transitionContext.containerView
        containerView.insertSubview(toViewController.view, belowSubview: fromViewController.view)

        // Setup the initial view states
        toViewController.view.frame = CGRect(x: -100, y: toViewController.view.frame.origin.y, width: fromViewController.view.frame.size.width, height: fromViewController.view.frame.size.height)

        let dimmingView = UIView(frame: CGRect(x: 0,y: 0, width: toViewController.view.frame.width, height: toViewController.view.frame.height))
        dimmingView.backgroundColor = UIColor.black
        dimmingView.alpha = 0.5

        toViewController.view.addSubview(dimmingView)

        UIView.animate(withDuration: transitionDuration(using: transitionContext),
                       delay: 0,
                       options: UIView.AnimationOptions.curveLinear,
                       animations: {
                        dimmingView.alpha = 0
                        toViewController.view.frame = transitionContext.finalFrame(for: toViewController)
                        fromViewController.view.frame = CGRect(x: toViewController.view.frame.size.width, y: fromViewController.view.frame.origin.y, width: fromViewController.view.frame.size.width, height: fromViewController.view.frame.size.height)
        },
                       completion: { finished in
                        dimmingView.removeFromSuperview()
                        transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
        }
        )
    }
}

PoppingNavigationController.swift

import UIKit

class PoppingNavigationController : UINavigationController, UINavigationControllerDelegate {
    var interactivePopTransition: UIPercentDrivenInteractiveTransition!

    override func viewDidLoad() {
        self.delegate = self
    }

    func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
        addPanGesture(viewController: viewController)
    }

    func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationController.Operation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        if (operation == .pop) {
            return CustomPopTransition()
        }
        else {
            return nil
        }
    }

    func navigationController(navigationController: UINavigationController, interactionControllerForAnimationController animationController: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
        if animationController.isKind(of: CustomPopTransition.self) {
            return interactivePopTransition
        }
        else {
            return nil
        }
    }

    func addPanGesture(viewController: UIViewController) {
        let popRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handlePanRecognizer(recognizer:)))
        viewController.view.addGestureRecognizer(popRecognizer)
    }

    @objc
    func handlePanRecognizer(recognizer: UIPanGestureRecognizer) {
        // Calculate how far the user has dragged across the view
        var progress = recognizer.translation(in: self.view).x / self.view.bounds.size.width
        progress = min(1, max(0, progress))
        if (recognizer.state == .began) {
            // Create a interactive transition and pop the view controller
            self.interactivePopTransition = UIPercentDrivenInteractiveTransition()
            self.popViewController(animated: true)
        }
        else if (recognizer.state == .changed) {
            // Update the interactive transition's progress
            interactivePopTransition.update(progress)
        }
        else if (recognizer.state == .ended || recognizer.state == .cancelled) {
            // Finish or cancel the interactive transition
            if (progress > 0.5) {
                interactivePopTransition.finish()
            }
            else {
                interactivePopTransition.cancel()
            }
            interactivePopTransition = nil
        }
    }
}