将子控制器添加到表视图单元时,不会调用viewWillAppear

Question

当我将子视图控制器添加到表视图单元格时,它看起来像子视图控制器的viewWillAppear没有被调用,只有viewDidAppear.

表视图控制器方法:

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
    let cell = tableView.dequeueReusableCellWithIdentifier("ShopInfoTableViewCell", forIndexPath: indexPath) as! ShopInfoTableViewCell
    self.addChildViewController(self.shopInfoViewController, toView: cell.containerView)
    return cell
}

查看控制器类别方法:

- (void)addChildViewController:(UIViewController *)childController toView:(UIView *)view
{
    [self addChildViewController:childController];
    [view addSubview:childController.view];
    [childController didMoveToParentViewController:self];

    [childController.view mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(view.mas_top);
        make.bottom.equalTo(view.mas_bottom);
        make.left.equalTo(view.mas_left);
        make.right.equalTo(view.mas_right);
    }];
}

任何想法为什么会发生？

Answer 1

- (void)addChildViewController:(UIViewController *)childController toView:(UIView *)view
{
    [self addChildViewController:childController];

    //add this
    [childController beginAppearanceTransition:YES animated:YES];
    [view addSubview:childController.view];
    [childController endAppearanceTransition];

    [childController didMoveToParentViewController:self];

    [childController.view mas_makeConstraints:^(MASConstraintMaker *make) {
        make.top.equalTo(view.mas_top);
        make.bottom.equalTo(view.mas_bottom);
        make.left.equalTo(view.mas_left);
        make.right.equalTo(view.mas_right);
    }];
}

同样,当你想要消失时,你应该调用它

    [childController beginAppearanceTransition:NO animated:YES];
    [childController.view removeFromSuperview];
    [childController endAppearanceTransition];