ios CAAnimation  实现push效果显示模态控制器（presentViewController）

// 要显示的控制器
　　BusinessWebController * businessVC = [[BusinessWebController alloc] init];
/**
* addSubView的方式
*/
//    　　[mainVC addChildViewController:businessVC];
//        [mainVC.view addSubview:businessVC.view];
///  在view的layer上 addAnimation （加 、 被加）
//        [mainVC.view.layer addAnimation:transition forKey:nil];
// 切换跟控制器的方式
　　[UIApplication sharedApplication].keyWindow.rootViewController = businessVC;
    [UIApplication sharedApplication].keyWindow.backgroundColor = [UIColor whiteColor];
// 构建push效果动画
        CATransition *transition = [CATransition animation];
        transition.duration = 0.15;
        transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionDefault];
        transition.type = kCATransitionPush;
        transition.subtype = kCATransitionFromRight;
        transition.delegate = self;
        [businessVC.view.layer addAnimation:transition forKey:nil];