如何在不与其交互的情况下访问XAML DataTemplate Listview中的元素

问题描述

我有一个C＃应用商店应用程序，并使用DataTemplate选择器来确定要在绑定到数组的ListView控件中使用的模板类型。因为它是模板化的，所以我无法为每个ListView行分配一个动态的x：Name。

I have a C# Store App and using DataTemplate Selectors to determine which type of Template to use in a ListView Control bound to an Array. Because it is templated, I cannot assign a dynamic x:Name to each ListView Row.

我需要能够按索引访问listview行并设置将它们设置为打开或关闭。我已经尝试过类似的事情，但是 .ItemContainerGenerator
.ContainerFromItem（item）; 返回 null 并我每次都会收到Nullable异常：

I need to be able to access the listview rows by Index and set the Visibility of them to On or Off. I have tried things like this, but the .ItemContainerGenerator .ContainerFromItem(item); return null and I get a Nullable exception every time:

做完一些研究后，看来上述解决方案仅在我触摸或设置了SelectedItem时才有效。请参阅此处

After doing some research, it appears that the above solution only works if I touch or have SelectedItem set. See here

我需要能够在页面加载（初始设置）和按钮单击时调用方法，并修改某些行的可见性。 / p>

I need to be able to Call a Method, both on Page load(initial setting) and also on button click and modify certain rows visibility.

推荐答案

这应该做您想要的事情：

This should do what you want:

var items = grid.ItemsSource as IEnumerable<MyModel>;
foreach (var item in items)
{
    var container = grid.ContainerFromItem(item);
    var button = Children(container)
        .Where(x => x is Button)
        .Select(x => x as Button)
        .Where(x => x.Name.Equals("MyButton"))
        .FirstOrDefault();
    if (button == null)
        continue;
    if (item.ShouldBeVisible)
        button.Visibility = Visibility.Visible;
    else
        button.Visibility = Visibility.Collapsed;
}

使用此功能：

public List<Control> Children(DependencyObject parent)
{
    var list = new List<Control>();
    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
    {
        var child = VisualTreeHelper.GetChild(parent, i);
        if (child is Control)
            list.Add(child as Control);
        list.AddRange(Children(child));
    }
    return list;
}

祝你好运！

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