Question

我正在寻找一种动态添加GroupDescriptions的方法，特别是在viewmodels中，我实际上在这样的代码后面添加了GroupDescription：

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();

        List<Country> items = new List<Country>();
        items.Add(new Country() { Name = "Italy", League = new League { Name = "Serie A" } }); // Added "new League"
        items.Add(new Country() { Name = "Italy", League = new League { Name = "Serie B" } });
        items.Add(new Country() { Name = "England", League = new League { Name = "Premiere League" } });
        items.Add(new Country() { Name = "Spain", League = new League { Name = "Primeira Division" } });
        lvUsers.ItemsSource = items;

        CollectionView view = (CollectionView)CollectionViewSource.GetDefaultView(lvUsers.ItemsSource);
        PropertyGroupDescription groupNations = new PropertyGroupDescription("Name");
        view.GroupDescriptions.Add(groupNations);
        PropertyGroupDescription groupCompetions = new PropertyGroupDescription("League.Name"); // Changed "League" to "League.Name"
        view.GroupDescriptions.Add(groupCompetions); // Fixed the variable name here

        lvUsers.ItemsSource = view; 
    }
}

public struct League
{
    public string Name { get; set; }
}

public struct Country
{
    public string Name { get; set; }
    public League League { get; set; } // added getter and setter
}

这是我的xaml：

<Window x:Class="GroupBox_Header.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:GroupBox_Header"
    mc:Ignorable="d"
    Title="MainWindow" Height="350" Width="525">
<Grid Margin="10">
    <ListView Name="lvUsers">
        <ListView.View>
            <GridView>
                <GridViewColumn Header="Home Team" Width="50" DisplayMemberBinding="{Binding HomeTeam}" />
                <GridViewColumn Header="Away Team" Width="50" DisplayMemberBinding="{Binding AwayTeam}" />
            </GridView>
        </ListView.View>

        <ListView.GroupStyle>
            <GroupStyle>
                <GroupStyle.ContainerStyle>
                    <Style TargetType="{x:Type GroupItem}">
                        <Setter Property="Template">
                            <Setter.Value>
                                <ControlTemplate>
                                    <Expander IsExpanded="True">
                                        <Expander.Header>
                                            <StackPanel Orientation="Horizontal">
                                                <TextBlock Text="{Binding Name}" FontWeight="Bold" Foreground="Gray" FontSize="22" VerticalAlignment="Bottom" />
                                                <TextBlock Text="{Binding ItemCount}" FontSize="22" Foreground="Green" FontWeight="Bold" FontStyle="Italic" Margin="10,0,0,0" VerticalAlignment="Bottom" />
                                                <TextBlock Text=" Items" FontSize="22" Foreground="Silver" FontStyle="Italic" VerticalAlignment="Bottom" />
                                            </StackPanel>
                                        </Expander.Header>
                                        <ItemsPresenter />
                                    </Expander>
                                </ControlTemplate>
                            </Setter.Value>
                        </Setter>
                    </Style>
                </GroupStyle.ContainerStyle>
            </GroupStyle>
            <GroupStyle>
                <GroupStyle.ContainerStyle>
                    <Style TargetType="{x:Type GroupItem}">
                        <Setter Property="Template">
                            <Setter.Value>
                                <ControlTemplate>
                                    <Expander IsExpanded="True">
                                        <Expander.Header>
                                            <StackPanel Orientation="Horizontal">
                                                <TextBlock Text="{Binding League}" FontWeight="Bold" Foreground="Gray" FontSize="22" VerticalAlignment="Bottom" />
                                            </StackPanel>
                                        </Expander.Header>
                                        <ItemsPresenter />
                                    </Expander>
                                </ControlTemplate>
                            </Setter.Value>
                        </Setter>
                    </Style>
                </GroupStyle.ContainerStyle>
            </GroupStyle>
        </ListView.GroupStyle>
    </ListView>
</Grid>

我想要做的是在ListView中绑定一个自动拥有组描述的集合。

Answer 1

如果我理解你的问题，你可以直接从ViewModel控制GroupDescriptions，从后面的代码控制或者创建一个自定义ListView，它可以绑定到ObservableCollection。

<强>视图模型

使用CollectionViewSource从ViewModel获取CollectionView。你可以说这是反模式，但我认为没关系。

代码

在后面的代码中创建依赖项属性，在更改时将更新视图的组描述符。然后在你xaml将该属性绑定到ViewModel。

自定义列表视图

从ListView继承并创建一个依赖项属性，让您绑定到ObservableCollection。

无论哪种方式，您都需要控制不同的场景，例如属性改变了，收藏改变了。

动态添加GroupDescription？

1 个答案: