總結(jié)---present／dismiss

modal presentation style

這個枚舉在iphone上常用的只有三個：fullScreen， overFullScreen，custom。
下面說明這三個的區(qū)別：
先點一下，在轉(zhuǎn)場過程中，系統(tǒng)會加入一個過渡控制器：UIPresentationController。
在自定義轉(zhuǎn)場的過程中，presentingView presentedView 會被add到過渡控制器的view上。
然而，一個view只能有一個父視圖，當他被add到過渡控制器上，前父視圖自然不再持有它，這也就導致了會有返回產(chǎn)生黑屏的情況。

• fullScreen：推出的視圖會占滿屏幕。動畫結(jié)束后，過渡控制器會移除add到自身的presentingView。
• overFullScreen：推出的視圖不是占滿屏幕，而且在presentedView的下方可以響應操作。動畫結(jié)束后，過渡控制器會不會移除add到自身的presentingView。與上方相反。
• custom：完全自定義。需要自定義實現(xiàn)過渡控制器（協(xié)議中的最后一個方法），一般繼承自系統(tǒng)的UIPresentationController即可。同樣不會移除presentingView

UIViewControllerTransitioningDelegate

vc.transitioningDelegate = self;
vc.modalPresentationStyle = @"枚舉";

- (nullable id <UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source;

- (nullable id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed;

- (nullable id <UIViewControllerInteractiveTransitioning>)interactionControllerForPresentation:(id <UIViewControllerAnimatedTransitioning>)animator;

- (nullable id <UIViewControllerInteractiveTransitioning>)interactionControllerForDismissal:(id <UIViewControllerAnimatedTransitioning>)animator;

- (nullable UIPresentationController *)presentationControllerForPresentedViewController:(UIViewController *)presented presentingViewController:(nullable UIViewController *)presenting sourceViewController:(UIViewController *)source

自動驅(qū)動

前兩個方法需要返回遵守UIViewControllerAnimatedTransitioning的對象，繼承自NSObject即可，下方是實現(xiàn)

- (NSTimeInterval)transitionDuration:(nullable id <UIViewControllerContextTransitioning>)transitionContext{
    return 0.5;
}
- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext{
    UIView *view = [transitionContext containerView];
    __block UIView *fromView = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey].view;
    __block UIView *toView = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey].view;
    [view addSubview:fromView];
    [view addSubview:toView];
    //根據(jù)需求操作兩個view即可。
    //[UIView animate....]  + view的位置只能是通過設置transForm來決定。
}

其中有個上下文變量 transitionContext 下方是key 。

UIKIT_EXTERN UITransitionContextViewControllerKey const UITransitionContextFromViewControllerKey 
UIKIT_EXTERN UITransitionContextViewControllerKey const UITransitionContextToViewControllerKey 

UIKIT_EXTERN UITransitionContextViewKey const UITransitionContextFromViewKey 
UIKIT_EXTERN UITransitionContextViewKey const UITransitionContextToViewKey 

手勢驅(qū)動器

中間兩個是需要返回遵守UIViewControllerInteractiveTransitioning的對象，繼承自UIPercentDrivenInteractiveTransition即可
在需要手勢驅(qū)動的控制器上加上手勢，在手勢的selector中根據(jù)手勢的狀態(tài)調(diào)用下方的方法即可。
第一個方法中的百分比：根據(jù)手勢拖拽的距離／屏幕的寬度

- (void)updateInteractiveTransition:(CGFloat)percentComplete;
- (void)cancelInteractiveTransition;
- (void)finishInteractiveTransition;

自定義過渡控制器

繼承自UIPresentationController，有六個方法需要重寫
初始化方法、過渡器進入時、進入完成、消失時、消失完畢以及presentedView呈現(xiàn)的frame
過渡器是特殊的控制器，自身并沒有view。
dimmingView是加在過渡器上的view，再加個手勢備用。如果用戶能夠點擊這個view，可以給予響應回饋。

- (instancetype)initWithPresentedViewController:(UIViewController *)presentedViewController presentingViewController:(UIViewController *)presentingViewController
{
    if ((self = [super initWithPresentedViewController:presentedViewController presentingViewController:presentingViewController])) {
        _dimmingView = [[UIView alloc] init];
        _dimmingView.backgroundColor = [UIColor clearColor];
        _dimmingView.alpha = 1;
        UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]bk_initWithHandler:^(UIGestureRecognizer *sender, UIGestureRecognizerState state, CGPoint location) {
            if (self.touchDimmingView) {
                self.touchDimmingView();
            }
        }];
        [_dimmingView addGestureRecognizer:tap];
    }
    return self;
}
- (void)presentationTransitionWillBegin
{
    _dimmingView.frame = self.containerView.bounds;
    [self.containerView addSubview:_dimmingView];
    [self.containerView addSubview:self.presentedView];
}
- (void)presentationTransitionDidEnd:(BOOL)completed
{
    if (!completed) {
        [_dimmingView removeFromSuperview];
    }
}
- (void)dismissalTransitionWillBegin
{
    [UIView animateWithDuration:0.3 animations:^{
        _dimmingView.alpha = 0;
    }];
}
- (void)dismissalTransitionDidEnd:(BOOL)completed
{
    if (completed) {
        [_dimmingView removeFromSuperview];
    }
}
-(CGRect)frameOfPresentedViewInContainerView
{
    return self.presentContnetSize;
}

總結(jié)--push／pop

第一個是手勢驅(qū)動器，第二個是動畫。
實現(xiàn)：代理方法的實現(xiàn)與上方提到的基本一致。按需實現(xiàn)即可。

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

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