问IOS/Objective-C:在缺少Storyboard Segue的情况下，是否可以在模式转换中使用自定义Segue？

EN

#import "ViewController.h"
#import "SlideDownAnimator.h"
#import "SlideUpAnimator.h"

@interface ViewController () <UIViewControllerTransitioningDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (IBAction)_presentCustomDownward:(id)sender {
    // setup a fake view controller we're going to present
    UIViewController *fakeSecondViewController = [[UIViewController alloc] init];
    fakeSecondViewController.view.backgroundColor = [UIColor blueColor];
    // make sure to set the desination view controller's transition delegate
    // this doesn't have to be set to self here, you can set it anything that will implement: UIViewControllerTransitioningDelegate
    fakeSecondViewController.transitioningDelegate = self;
    // when we call present on the view controller it asks the transitioningDelegate for an animation coordinator which we're going to provide below
    [self.navigationController presentViewController:fakeSecondViewController animated:YES completion:^{
        // dismis after a couple seconds to show what the custom dismiss looks like (obviously this is just for the example code, you will handle your own dismissal)
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0f * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
            [self.navigationController dismissViewControllerAnimated:YES completion:nil];
        });
    }];
}

// delegate call for presentation
- (id<UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented
                                                                  presentingController:(UIViewController *)presenting
                                                                      sourceController:(UIViewController *)source {

    // return our own custom Animator class (which adheres to UIViewControllerAnimatedTransitioning protocol)
    return [[SlideDownAnimator alloc] init];
}

// delegate call for dismissal
- (id<UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed {
    // return our own custom Animator class (which adheres to UIViewControllerAnimatedTransitioning protocol)
    return [[SlideUpAnimator alloc] init];
}

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface SlideDownAnimator : NSObject <UIViewControllerAnimatedTransitioning>

@end

NS_ASSUME_NONNULL_END

#import "SlideDownAnimator.h"

@implementation SlideDownAnimator

- (NSTimeInterval)transitionDuration:(nullable id<UIViewControllerContextTransitioning>)transitionContext {
    return 0.4f;
}

- (void)animateTransition:(nonnull id<UIViewControllerContextTransitioning>)transitionContext {
    // grab the toViewController (the vc being presented)
    UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    // manually add it to our container view
    [[transitionContext containerView] addSubview:toViewController.view];
    // get the frame so we can do some of our own animations on it
    CGRect toVCFrame = toViewController.view.frame;
    CGFloat toVCHeight = toVCFrame.size.height;
    // offset the y coordiante by it's height so that it's completely above our current screen
    toVCFrame.origin.y = -toVCHeight;
    // set the initial frame so it's above our screen
    [toViewController.view setFrame:toVCFrame];

    [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
        // animate the y position to 0 so it slides down
        CGRect finalVCFrame = toViewController.view.frame;
        finalVCFrame.origin.y = 0;
        [toViewController.view setFrame:finalVCFrame];
    } completion:^(BOOL finished) {
        // make sure to call this so we'll call back to our presentViewdController's completion block
        [transitionContext completeTransition:![transitionContext transitionWasCancelled]];
    }];
}

@end

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface SlideUpAnimator : NSObject <UIViewControllerAnimatedTransitioning>

@end

NS_ASSUME_NONNULL_END

#import "SlideUpAnimator.h"

@implementation SlideUpAnimator

- (NSTimeInterval)transitionDuration:(nullable id<UIViewControllerContextTransitioning>)transitionContext {
    return 0.4f;

}

- (void)animateTransition:(nonnull id<UIViewControllerContextTransitioning>)transitionContext {
    // grab our fromViewController (the vc being dismissed)
    UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    // and our toViewController (the vc that will be shown after dismissal)
    UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    // add our toViewController as a subview of our container view (make sure to add it beneath the dismissing view controller so we can let it complete it's animation first)
    [[transitionContext containerView] insertSubview:toViewController.view belowSubview:fromViewController.view];
    [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
        // push the view back up above the screen
        CGRect fromVCFrame = fromViewController.view.frame;
        fromVCFrame.origin.y = -fromVCFrame.size.height;
        [fromViewController.view setFrame:fromVCFrame];
    } completion:^(BOOL finished) {
        // make sure to call this so we'll call back to our presentViewdController's completion block
        [transitionContext completeTransition:![transitionContext transitionWasCancelled]];
    }];

}

@end