ios - Cocoa 编程的概念或技术问题

Question

我发现自己需要从 View Controller 的 View 访问它。

方法如下

-(void)changePageView:(UIViewController*)newviewcont withtransitiontype:(int)t andtransitionspeed:(int)s
{
    //Remove whatever view is currently loaded at index 0, this index is only to be used by "page" views
    UIView *oldview = [self.view.subviews objectAtIndex:0];

    [UIView beginAnimations:@"View Flip" context:nil];
    [UIView setAnimationDuration:s];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:self.view cache:YES];
    [newviewcont viewWillAppear:YES];
    //[oldview viewWillDisappear:YES];
    [oldview removeFromSuperview];
    [self.view insertSubview:newviewcont.view atIndex:0];
    //[oldview viewDidDisappear:YES];
    [newviewcont viewDidAppear:YES];

}

基本上，我正在尝试编写一个由根 Controller 调用的通用 View 切换方法，以从根 Controller View 中交换 subview Controller View 。

我传入一个 subview Controller ，并且能够删除当前的 subview 。但为了执行正确的 View 切换动画，我需要访问当前 View View Controller 。这是错误的做法吗？可以这样做吗？

Answer 1

我向根 Controller 添加了一个成员，该成员保留当前 subview Controller (currentController) 并在 Controller 交换完成时引用它

-(void)changePageView:(UIViewController*)newviewcont withtransitiontype:(int)t andtransitionspeed:(int)s
{


    [UIView beginAnimations:@"View Flip" context:nil];
    [UIView setAnimationDuration:s];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:self.view cache:YES];
    [newviewcont viewWillAppear:YES];
    [self.currentController viewWillDisappear:YES];
    [self.currentController.view removeFromSuperview];
    [self.view insertSubview:newviewcont.view atIndex:0];
    [self.currentController viewDidDisappear:YES];
    [newviewcont viewDidAppear:YES];
    [UIView commitAnimations];


    self.currentController = newviewcont;

}