0

在按钮上单击 GalaSoft.MvvmLight.Messaging 消息会在所有注册了消息接收器的视图模型中触发。异步获取新的数据列表并用于更新 UI。UI 更新,但是当我调用以下命令时

var contentControls = VisualTreeQueryHelper.FindChildrenOfType(this).ToList();

即使屏幕上的视觉列表是正确的,它仍然反映旧列表的内容计数和索引。这打破了我使用索引和列表大小来设置焦点的焦点逻辑。

如果我离开视图并返回,则更正 contentControls 列表。

private IList<CoreViewModel> itemViewModels;
public IList<CoreViewModel> ItemViewModels
{
    get { return this.itemViewModels; }
    set
    {
        this.itemViewModels = value;
        RaisePropertyChanged("ItemViewModels");
    }
}

 public static IEnumerable<T> FindChildrenOfType<T>(DependencyObject objectInParentTreeToStartFrom)
    where T : DependencyObject
{
    List<T> list = new List<T>();

    FindChildrenOfTypeImpl<T>(objectInParentTreeToStartFrom, list);

    return list;
}

private static void FindChildrenOfTypeImpl<T>(DependencyObject objectInParentTreeToStartFrom, List<T> list)
    where T : DependencyObject
{
    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(objectInParentTreeToStartFrom); i++)
    {
        DependencyObject child = VisualTreeHelper.GetChild(objectInParentTreeToStartFrom, i);

        if (child is T)
        {
            list.Add(child as T);
        }
        else
        {
            FindChildrenOfTypeImpl(child, list);    
        }
    }
}
4

0 回答 0