iOS 自定义转场动画篇

前言: 自定义转场动画其实并不难, 关键在于能够明白思路, 也就是操作步骤. 本篇博客主要以present转场动画为例, 进行分析, 操作, 如有错误欢迎简信与我交流.

不进行修改的话, presentviewcontroller:animated:completion:相信这个方法很多人都是用过, 称作模态推出界面, 默认都是从屏幕下方推出新的控制器.
自定义的目的就是为了修改固定的推出方式, 同时加上你想要的动画.

一个关键的概念: uiviewcontrolleranimatedtransitioning控制动画的协议, 需要自己实现这个. 下面来一看看代码如何进行实现.

 

@interface viewcontroller ()

跳转点击方法

- (void)click:(uibutton *)sender
{
  modelviewcontroller *modalviewcontroller = [modelviewcontroller new];
    // 指定代理
  modalviewcontroller.transitioningdelegate = self;
    // style = 自定义方式
  modalviewcontroller.modalpresentationstyle = uimodalpresentationcustom;
  [self presentviewcontroller:modalviewcontroller
                      animated:yes
                     completion:null];
}

uiviewcontrollertransitioningdelegate

// 修改动画的两个相关的协议方法, 建议仔细查看uiviewcontrollertransitioningdelegate里面的注释
-(id)animationcontrollerforpresentedcontroller:(uiviewcontroller *)presented
                                 presentingcontroller:(uiviewcontroller *)presenting
                                   sourcecontroller:(uiviewcontroller *)source
{
    // 推出动画 - 下面会给出代码 我参照pop动画demo写的.
  return [presentanimator new];
}

- (id)animationcontrollerfordismissedcontroller:(uiviewcontroller *)dismissed
{
    // 退出 
  return [dismissanimator new];
}
// 想要实现手势控制可在这个方法中进行修改
-(id)interactioncontrollerfordismissal:(id)animator {

}

关键在于动画如何实现 分别进行的实现presentanimator, dismissanimator的实现.

uiviewcontrolleranimatedtransitioning使用这个协议进行修改.

@interface presentanimator : nsobject 

presentanimator.m

// 交互所用时间
- (nstimeinterval)transitionduration:(id )transitioncontext
{
  return 0.5f;
}
// 具体动画方式, 上面提到的pop
- (void)animatetransition:(id )transitioncontext
{
    // 这里拿到即将新推出的vc的view
  uiview *toview = [transitioncontext viewcontrollerforkey:uitransitioncontexttoviewcontrollerkey].view;
    // 这里设置退出view具体如何设置
  toview.frame = cgrectmake(0,0, screen_width, screen_height);
  toview.center = cgpointmake(transitioncontext.containerview.center.x, -transitioncontext.containerview.center.y);
 
  [transitioncontext.containerview addsubview:toview];
    // pop动画 
  popspringanimation *positionanim = [popspringanimation animationwithpropertynamed:kpoplayerpositiony];
  positionanim.tovalue = @(transitioncontext.containerview.center.y);
  positionanim.springbounciness = 10;
  [positionanim setcompletionblock:^(popanimation *anim, bool finished) {
    [transitioncontext completetransition:yes];
  }];
  popspringanimation *scaleanim = [popspringanimation animationwithpropertynamed:kpoplayerscalexy];
  scaleanim.springbounciness = 20;
  scaleanim.fromvalue = [nsvalue valuewithcgpoint:cgpointmake(1.2, 1.4)];
 
  [toview.layer pop_addanimation:positionanim forkey:@"positionanimation"];
  [toview.layer pop_addanimation:scaleanim forkey:@"scaleanimation"];
}

dismissanimator.m

- (nstimeinterval)transitionduration:(id )transitioncontext
{
  return 0.5f;
}

- (void)animatetransition:(id )transitioncontext
{
    // fromvc 很好理解吧?? 就是从哪个控制器推过来回到哪里去.
  uiviewcontroller *fromvc = [transitioncontext viewcontrollerforkey:uitransitioncontextfromviewcontrollerkey];
  popbasicanimation *offscreenanimation = [popbasicanimation animationwithpropertynamed:kpoplayerpositiony];
  offscreenanimation.tovalue = @(-fromvc.view.layer.position.y);
  [offscreenanimation setcompletionblock:^(popanimation *anim, bool finished) {
    [transitioncontext completetransition:yes];
  }];
  [fromvc.view.layer pop_addanimation:offscreenanimation forkey:@"offscreenanimation"];
}

顺便值得一提的是uinavigationcontroller转场的动画也是可以自定义的. 通过这个
uinavigationcontrollerdelegate来完成

    // 签订这个协议
  self.navigationcontroller.delegate = self;

- (id) navigationcontroller:(uinavigationcontroller *)navigationcontroller animationcontrollerforoperation:(uinavigationcontrolleroperation)operation fromviewcontroller:(uiviewcontroller *)fromvc toviewcontroller:(uiviewcontroller *)tovc
{
 
  if (operation == uinavigationcontrolleroperationpush) {
        // 动画的方式不变
    return [presentanimator new];
  }else{
    return nil;
  }
}