iOS-授之以鱼不如授之以渔=_=带你升入理解自定义转场动画

1.前言

说到APP的转场动画，大家一定会想到push和pop来实现转场动画，这是苹果用了很多年提供的自带的方法，而且我相信大家在APP开发的时候，很多小伙伴都会选择自带的转场动画，很少去自定义，不论你是大神还是小白菜，本小白菜也是一样，毕竟作为程序员的我们已经很累了，项目经理不提我们也很少回去做，但是我们工作不是为了工作而工作，是为了丰富充实自己。

2.自定义UINavigationController

当UINavigationController对UIViewController进行pop或者push的时候，我们需要让UIViewController知道我们进行这些操作，这里我们需要UINavigationController的代理UINavigationControllerDelegate，UINavigationControllerDelegate的代理方法有六种，这里我们只需要一张，那就是：

#pragma mark - UINavigationControllerDelegate- (id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController *)fromVC toViewController:(UIViewController *)toVC;

代码如下：

- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view.    [self uiConfig];}- (void)uiConfig{    self.delegate = self;}#pragma mark - UINavigationControllerDelegate- (id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController *)fromVC toViewController:(UIViewController *)toVC{    ZFJ_Animation *ZFJAnimation = [[ZFJ_Animation alloc]init];    ZFJAnimation.operation = operation;    ZFJAnimation.animationType = _animationType;    return (id)ZFJAnimation;}

3.自定义动画（ZFJ_Animation）

ZFJ_Animation这个类继承于NSObject，参数如下：

#import <Foundation/Foundation.h>#import <UIKit/UIKit.h>typedef NS_ENUM(NSInteger, ZFJ_AnimationType) {    ZFJ_AnimationType1,    ZFJ_AnimationType2,    ZFJ_AnimationType3};@interface ZFJ_Animation : NSObject@property (nonatomic,assign) UINavigationControllerOperation operation;@property (nonatomic,assign) ZFJ_AnimationType animationType;//动画类型@end

 

参数说明
operation用来接收控制器的转场类型，UINavigationControllerOperation是个枚举类型，类型如下：

typedef NS_ENUM(NSInteger, UINavigationControllerOperation) {    UINavigationControllerOperationNone,    UINavigationControllerOperationPush,    UINavigationControllerOperationPop,};

看到这个枚举大家就明白了，看你的UIViewController是push还是pop，这样我们可以根据这个类型来定义不同的类型；

animationType我自定义转场的动画类型，也是一个枚举，因为在ZFJ_Animation里面我打算定义几个不同的动画类型；

当然最重要的就是这个动画控制器的类必须遵循一个代理方法UIViewControllerAnimatedTransitioning，代理的里面的两个方法也必须要实现，代理方法如下：

@protocol UIViewControllerAnimatedTransitioning <NSObject>// This is used for percent driven interactive transitions, as well as for// container controllers that have companion animations that might need to// synchronize with the main animation.- (NSTimeInterval)transitionDuration:(nullable id <UIViewControllerContextTransitioning>)transitionContext;// This method can only  be a nop if the transition is interactive and not a percentDriven interactive transition.- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext;@optional

代理说明

a.transitionDuration：这个方法返回自定义动画的执行时间；

b.animateTransition：这个方法是我们这个动画管理类的核心，我们需要自定义什么样的动画全部在这里面执行；

上代码：

#pragma mark - UIViewControllerAnimatedTransitioning- (NSTimeInterval)transitionDuration:(nullable id <UIViewControllerContextTransitioning>)transitionContext{    return 0.4;}- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext{    UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];        UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];        UIView *containerView = transitionContext.containerView;    if(self.animationType == ZFJ_AnimationType1){        //动画一        [containerView addSubview:toViewController.view];                CGRect fromViewStartFrame = [transitionContext initialFrameForViewController:fromViewController];        CGRect toViewEndFrame = [transitionContext finalFrameForViewController:toViewController];        CGRect fromViewEndFrame = fromViewStartFrame;        CGRect toViewStartFrame = toViewEndFrame;                if(self.operation == UINavigationControllerOperationPush){            //PUSH            toViewStartFrame.origin.y -= toViewEndFrame.size.height;        }else if (self.operation == UINavigationControllerOperationPop){            //POP            fromViewEndFrame.origin.y -= fromViewStartFrame.size.height;            [containerView sendSubviewToBack:toViewController.view];        }        //这里面 你可以自定义动画        fromViewController.view.frame = fromViewStartFrame;        toViewController.view.frame = toViewStartFrame;                //动画        CGFloat duration = [self transitionDuration:transitionContext];        [UIView animateWithDuration:duration animations:^{            fromViewController.view.frame = fromViewEndFrame;            toViewController.view.frame = toViewEndFrame;        } completion:^(BOOL finished) {            [transitionContext completeTransition:YES];        }];    }else if(self.animationType == ZFJ_AnimationType2){        //动画二    }else if (self.animationType == ZFJ_AnimationType3){        //动画三    }    }

说明：这里面我定义了三种动画，因为页面展示太长，我就展示一种动画。

4.UIViewController调用

- (void)nextBtnClick:(UIButton *)nextBtn{    NSInteger index = nextBtn.tag - 100;    ZFJ_NavViewController *nvc = (ZFJ_NavViewController *)self.navigationController;    nvc.animationType = (ZFJ_AnimationType)index;    ZFJ_NextViewController *zvc = [[ZFJ_NextViewController alloc]init];    [nvc pushViewController:zvc animated:YES];}

5.效果展示

6.DEMO下载

点击下载

http://download.csdn.net/detail/u014220518/9883291