是否可以将 CollectionView 与 LongListSelector 一起使用进行分组? [英] Is it possible to use CollectionView with LongListSelector for grouping?

问题描述

我正在尝试将 LongListSelector 与 CollectionView 结合使用.似乎 CollectionView 拥有所需的所有东西"，但是当我将两者连接起来时，什么也没有发生.这是我到目前为止所拥有的:

I am trying to use LongListSelector in conjunction with CollectionView. It seems like CollectionView has all the "stuff" needed, but when I connect the two, nothing happens. Here's what I have so far:

在我的控件的构造函数(包含 LLS 的那个人)中，我构造了 CollectionView:

In my control's ctor (the guy that contains the LLS), I construct the CollectionView:

GroupDescription group = new PropertyGroupDescription("FullName", new FirstLetterConverter(true, true));
m_view.GroupDescriptions.Add(group);

然后，每当相关的依赖属性(包含我想放入 LLS 的列表的那个)发生变化时，我就会将其分配给 m_view 并将组分配给 ItemsSource:

Then, whenever the relevant dependency property (the one that contains the list I want to put in the LLS) changes, I go and assign that to m_view and assign the groups to ItemsSource:

private void FriendsChanged()
{
    m_view.Source = Friends;
    friendList.ItemsSource = m_view.View.Groups;

当我检查 .Groups 属性时，信息似乎是 kosher 的 - 它有正确数量的项目，并且每个项目都有似乎正确的子项目.但是，看起来一切都是内部的，因此 LLS 似乎无法显示相关信息.当我用模拟集合替换 CollectionView 内容时，LLS 会显示信息(因此我非常确信 LLS 设置正确)

When I inspect the .Groups property, the information seems to be kosher - it has the right amount of items and each item has child-items that seem to be correct. However, it looks like everything is internal and as such the LLS seems to be unable to display the relevant info. When I replace the CollectionView stuff with a mock collection, the LLS does show information (so I am pretty confident that the LLS is set up correctly)

以下是我在 LLS 中使用的内容 - 请注意，我在几个地方使用了XXXX"而不是绑定，以确保不会因绑定错误而以某种方式破坏:

Here's what I am using with the LLS - note that instead of binding, I use "XXXX" in a few places to make sure that nothing is somehow breaking because of faulty binding:

<toolkit:LongListSelector x:Name="friendList">
  <toolkit:LongListSelector.ItemTemplate>
    <DataTemplate>
      <Grid>
        <Grid.ColumnDefinitions>
          <ColumnDefinition Width="auto"/>
          <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Image Source="{Binding ThumbnailImage}" Width="62" Height="62"/>
        <TextBlock Text="{Binding FullName}"/>
      </Grid>
    </DataTemplate>
  </toolkit:LongListSelector.ItemTemplate>
  <toolkit:LongListSelector.GroupHeaderTemplate>
    <DataTemplate>
      <Border Background="{StaticResource PhoneAccentBrush}" Padding="{StaticResource PhoneTouchTargetOverhang}" Width="200" HorizontalAlignment="Left">
        <!--<TextBlock Text="{Binding Name}" Style="{StaticResource PhoneTextLargeStyle}"/>-->
        <TextBlock Text="XXXX" Style="{StaticResource PhoneTextLargeStyle}"/>
      </Border>
    </DataTemplate>
  </toolkit:LongListSelector.GroupHeaderTemplate>
  <toolkit:LongListSelector.GroupItemTemplate>
    <DataTemplate>
      <Border Background="{StaticResource PhoneAccentBrush}" Margin="{StaticResource PhoneTouchTargetOverhang}" Padding="{StaticResource PhoneTouchTargetOverhang}" Width="180">
        <TextBlock Text="XXXX" Style="{StaticResource PhoneTextLargeStyle}"/>
        <!--<TextBlock Text="{Binding Name}" Style="{StaticResource PhoneTextLargeStyle}"/>-->
      </Border>
    </DataTemplate>
  </toolkit:LongListSelector.GroupItemTemplate>
</toolkit:LongListSelector>

推荐答案

我遇到了同样的问题.LongListSelector 似乎不适用于 CollectionView.我通过将其绑定到 ObservableCollection 来解决这个问题.我花了两天时间弄清楚为什么 LongListSelector 没有显示任何项目.奇怪的是 CollectionView.IsEmpty 可以用来改变可见性(当然是通过转换器).但是不能显示项目.

I had the same problem. It seems LongListSelector doesn't work with CollectionView. I solve the issue by binding it to an ObservableCollection instead. I spent two days figuring out why LongListSelector wasn't showing any item. The strange thing is that CollectionView.IsEmpty works for to turn the Visibility (thru a Converter of course). But it doesn't work to show the items.

这篇关于是否可以将 CollectionView 与 LongListSelector 一起使用进行分组?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！