iOS开发自定义转场动画

1、转场动画

　　iOS7之后开发者可以自定义界面切换的转场动画，就是在模态弹出（present、dismiss），Navigation的（push、pop），TabBar的系统切换效果之外自定义切换动画！

　　模态弹出自定义出push、pop效果，可以侧滑：

2、实现步骤

　　2.1、自定义转场动画

　　　　1》创建自定义文件

@interface CustomTransform : NSObject<UIViewControllerAnimatedTransitioning>

　　　　2》实现UIViewControllerAnimatedTransitioning方法

//设置转场时间
- (NSTimeInterval)transitionDuration:(nullable id <UIViewControllerContextTransitioning>)transitionContext;
//设置转场效果
- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext;

　　　　.m相关类说明：

//表示转场动画上下文
UIViewControllerContextTransitioning
//当前控制器fromVC和目标控制器toVC
//vc1-->present-->vc2: fromVC是vc1，toVC是vc2
//vc2-->dismiss-->vc1: fromVC是vc2，toVC是vc1
UIViewController *fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
UIViewController *toVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
//对应控制器的view视图
UIView *fromView =[transitionContext viewForKey:UITransitionContextFromViewKey];
UIView *toView =[transitionContext viewForKey:UITransitionContextToViewKey];

//presentingViewController,presentedViewController
vc1-->present-->vc2,vc1.presentedViewController 就是vc2；vc2.presentingViewController 就是vc1。

//更新动画进度
- (void)updateInteractiveTransition:(CGFloat)percentComplete;
//转场结束
- (void)finishInteractiveTransition;
//转场取消
- (void)cancelInteractiveTransition;

　　　　自定义文件：

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

typedef NS_ENUM(NSInteger, PresentType){
    PresentTypePresent,
    PresentTypeDismiss
};

@interface CustomTransform : NSObject<UIViewControllerAnimatedTransitioning>

+ (instancetype)makeWithTransitionType:(PresentType)type;
- (instancetype)initWithTransitionType:(PresentType)type;


@end

#import "CustomTransform.h"

@interface CustomTransform()

@property(nonatomic, assign)PresentType type;
@property(nonatomic, strong)UIView *containerView;
@end

@implementation CustomTransform
+ (instancetype)makeWithTransitionType:(PresentType)type
{
    return [[self alloc] initWithTransitionType:type];
}

- (instancetype)initWithTransitionType:(PresentType)type
{
    if (self == [super init]) {
        _type = type;
    }
    return self;
}

- (NSTimeInterval)transitionDuration:(nullable id <UIViewControllerContextTransitioning>)transitionContext
{
    return .5;
}


- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
    switch (_type) {
        case PresentTypePresent:
            [self presentTransform:transitionContext];
            break;
        case PresentTypeDismiss:
            [self dismissTransform:transitionContext];
            break;
        default:
            break;
    }
    
}

- (void)presentTransform:(id<UIViewControllerContextTransitioning>)transitionContext
{
    UIViewController *fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    UIViewController *toVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    self.containerView = [transitionContext containerView];
    
    UIView *fromView =[transitionContext viewForKey:UITransitionContextFromViewKey];
    UIView *toView =[transitionContext viewForKey:UITransitionContextToViewKey];
    [self.containerView addSubview:toView];
    CGRect visibleFrame = [transitionContext initialFrameForViewController:fromVC];
    CGRect rightHiddenFrame = CGRectMake( CGRectGetWidth(visibleFrame), 0,CGRectGetWidth(visibleFrame),CGRectGetHeight(visibleFrame));
    CGRect leftHiddenFrame =CGRectMake(- CGRectGetWidth(visibleFrame), 0, CGRectGetWidth(visibleFrame), CGRectGetHeight(visibleFrame));
    fromView.frame = visibleFrame;
    toView.frame = rightHiddenFrame;
    fromView.layer.masksToBounds = toView.layer.masksToBounds = YES;
    [self.containerView insertSubview:toView atIndex:0];
    [UIView animateWithDuration:.5
                     animations:^{
                         fromView.frame = leftHiddenFrame;
                         toView.frame = visibleFrame;
                     }
                     completion:^(BOOL finished) {
                         if ([transitionContext transitionWasCancelled]) {
                             [toView removeFromSuperview];
                         }
                         [transitionContext completeTransition:![transitionContext transitionWasCancelled]];
                     }];
    
}

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

    UIViewController *fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    UIViewController *toVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    self.containerView = [transitionContext containerView];
    
    UIView *fromView =[transitionContext viewForKey:UITransitionContextFromViewKey];
    UIView *toView =[transitionContext viewForKey:UITransitionContextToViewKey];
    [self.containerView addSubview:toView];
    CGRect visibleFrame = [transitionContext initialFrameForViewController:fromVC];
    CGRect rightHiddenFrame = CGRectMake( CGRectGetWidth(visibleFrame), 0,CGRectGetWidth(visibleFrame),CGRectGetHeight(visibleFrame));
    CGRect leftHiddenFrame =CGRectMake(- CGRectGetWidth(visibleFrame), 0, CGRectGetWidth(visibleFrame), CGRectGetHeight(visibleFrame));
    fromView.frame = visibleFrame;
    toView.frame = leftHiddenFrame;
    fromView.layer.masksToBounds = toView.layer.masksToBounds = YES;
    [UIView animateWithDuration:.5
                     animations:^{
                         fromView.frame = rightHiddenFrame;
                         toView.frame = visibleFrame;
                     }
                     completion:^(BOOL finished) {
                         if ([transitionContext transitionWasCancelled]) {
                             [toView removeFromSuperview];
                         }
                         [transitionContext completeTransition:![transitionContext transitionWasCancelled]];
                     }];
}

@end

　　2.2、自定义交互手势

　　　　1》创建自定义文件

@interface CustonInteractive : UIPercentDrivenInteractiveTransition

　　　　因为UIPercentDrivenInteractiveTransition : NSObject <UIViewControllerInteractiveTransitioning>，所以自定义时继承遵循UIViewControllerInteractiveTransitioning协议的UIPercentDrivenInteractiveTransition子类！

　　　　2》相关文件：

#import <UIKit/UIKit.h>

@interface CustonInteractive : UIPercentDrivenInteractiveTransition

@property (nonatomic, assign) BOOL interacting;

- (void)wireToViewController:(UIViewController*)viewController;

@end

#import "CustonInteractive.h"


@interface CustonInteractive()
@property (nonatomic, strong) UIViewController *presentingVC;

@end

@implementation CustonInteractive
-(void)wireToViewController:(UIViewController *)viewController
{
    self.presentingVC = viewController;
    [self prepareGestureRecognizerInView:viewController.view];
}

- (void)prepareGestureRecognizerInView:(UIView*)view {
    UIPanGestureRecognizer *gesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handleGesture:)];
    [view addGestureRecognizer:gesture];
}
- (void)handleGesture:(UIPanGestureRecognizer *)gestureRecognizer {
    CGFloat progress = [gestureRecognizer translationInView:gestureRecognizer.view.superview].x / (self.presentingVC.view.bounds.size.width * 1.0);
    progress = MIN(1.0, MAX(0.0, progress));//把这个百分比限制在0~1之间
    NSLog(@"===%lf",progress);
    if (gestureRecognizer.state == UIGestureRecognizerStateBegan) {
        self.interacting = YES;
        [self.presentingVC dismissViewControllerAnimated:YES completion:nil];
    }
    else if (gestureRecognizer.state == UIGestureRecognizerStateChanged){
        if (self.interacting) {
            [self updateInteractiveTransition:progress];
        }
    }else if (gestureRecognizer.state == UIGestureRecognizerStateCancelled||gestureRecognizer.state==UIGestureRecognizerStateEnded){
        if (self.interacting) {
            if (progress>0.5) {
                [self finishInteractiveTransition];
            }else{
                [self cancelInteractiveTransition];
            }
            self.interacting = NO;
        }
    }
}

@end

　　2.3、使用自定义转场动画

　　　　1》设置代理（以模态弹出为例）设置目标控制器的 transitioningDelegate

- (IBAction)present:(id)sender {
    PresentedViewController *vc = [[PresentedViewController alloc] init];
    vc.transitioningDelegate = self;
    [_transitionController wireToViewController:vc];
    [self presentViewController:vc animated:YES completion:nil];
}

 　　　　附加：Navigation和TabBar代理设置（self.delegate = self）

　　　　2》实现UIViewControllerTransitioningDelegate代理方法

//设置弹出时动画协议
- (nullable id <UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source;
//设置消失时动画协议
- (nullable id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed;
//设置消失时手势协议
- (nullable id <UIViewControllerInteractiveTransitioning>)interactionControllerForDismissal:(id <UIViewControllerAnimatedTransitioning>)animator;

　　　　vc1的.m文件：

#import "PresentingViewController.h"
#import "CustomTransform.h"
#import "CustonInteractive.h"
#import "PresentedViewController.h"


#import "SecondTransform.h"
#import "SecondInteractive.h"
@interface PresentingViewController ()<UIViewControllerTransitioningDelegate,UINavigationControllerDelegate,UITabBarControllerDelegate>{
    SecondTransform *_presentAnimation;
    SecondInteractive *_transitionController;
}

@end

@implementation PresentingViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    _presentAnimation = [SecondTransform new];
    _transitionController = [SecondInteractive new];
    // Do any additional setup after loading the view from its nib.
}
- (IBAction)present:(id)sender {
    PresentedViewController *vc = [[PresentedViewController alloc] init];
    vc.transitioningDelegate = self;
    [_transitionController wireToViewController:vc];
    [self presentViewController:vc animated:YES completion:nil];
}
- (nullable id <UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source
{
    return _presentAnimation;
}

- (nullable id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed
{
    return [SecondTransform makeWithTransitionType:PresentTransformAnimationTypeDismissed];
}

-(id<UIViewControllerInteractiveTransitioning>)interactionControllerForDismissal:(id<UIViewControllerAnimatedTransitioning>)animator {
    return _transitionController.isInterraction ? _transitionController : nil;
}
@end

 　　　　Navigation和TabBar的代理方法：

#pragma mark---UINavigationControllerDelegate
/*
- (nullable id <UIViewControllerInteractiveTransitioning>)navigationController:(UINavigationController *)navigationController
                                   interactionControllerForAnimationController:(id <UIViewControllerAnimatedTransitioning>) animationController NS_AVAILABLE_IOS(7_0);

- (nullable id <UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController
                                            animationControllerForOperation:(UINavigationControllerOperation)operation
                                                         fromViewController:(UIViewController *)fromVC
                                                           toViewController:(UIViewController *)toVC  NS_AVAILABLE_IOS(7_0);
*/

#pragma mark-UITabBarControllerDelegate
/*
- (nullable id <UIViewControllerInteractiveTransitioning>)tabBarController:(UITabBarController *)tabBarController
                               interactionControllerForAnimationController: (id <UIViewControllerAnimatedTransitioning>)animationController NS_AVAILABLE_IOS(7_0);

- (nullable id <UIViewControllerAnimatedTransitioning>)tabBarController:(UITabBarController *)tabBarController
                     animationControllerForTransitionFromViewController:(UIViewController *)fromVC
                                                       toViewController:(UIViewController *)toVC  NS_AVAILABLE_IOS(7_0);
*/