我已经使用ListView实现了Expander，但是尝试绑定到ViewModel的属性时，没有填充Header Text。 ReportCategoryTypeName是我要绑定到Expander标头的内容，但是所有标头都是空白。

如果我对文本值进行硬编码，则一切正常。

我的代码基于：https://www.wpf-tutorial.com/listview-control/listview-grouping/，我知道它一直在使用代码。

这是背后的代码：ucAppReports.xaml.cs

using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;

namespace App.Pages
{
    public partial class ucAppReports : UserControl
    {
        public ucAppReports()
        {
            InitializeComponent();

            CollectionView cv = (CollectionView)CollectionViewSource.GetDefaultView(lvReports.ItemsSource);
            PropertyGroupDescription groupDescription = new PropertyGroupDescription("ReportCategoryTypeName");
            cv.GroupDescriptions.Add(groupDescription);

        }

    }
}

这是ucAppReports.xaml中的ListView

<ListView x:Name="lvReports"  HorizontalAlignment="Stretch" 
    ItemsSource="{Binding Reports}"
    SelectedItem="{Binding SelectedReport}" Grid.Row="1" 
    Grid.Column="0" Background="Green" BorderBrush="Purple" ScrollViewer.HorizontalScrollBarVisibility="Disabled">
    <ListView.ItemContainerStyle>
        <Style TargetType="{x:Type ListViewItem}">
            <Style.Triggers>
                <Trigger Property="IsSelected"  Value="true" >
                    <Setter Property="Foreground" Value="White" />
                    <Setter Property="Background" Value="Blue" />
                </Trigger>
            </Style.Triggers>
            <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
        </Style>
    </ListView.ItemContainerStyle>
    <ListView.groupstyle>
        <groupstyle>
            <groupstyle.ContainerStyle>
                <Style TargetType="{x:Type GroupItem}">
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate>
                                <Expander IsExpanded="False">
                                    <Expander.Header>
                                        <StackPanel Orientation="Horizontal">
                                            <TextBlock Text="{Binding ReportCategoryTypeName}" FontWeight="Bold" Foreground="Black" FontSize="22" VerticalAlignment="Bottom" />
                                            <!--<TextBlock Text="Hello" FontWeight="Bold" Foreground="Black" FontSize="22" VerticalAlignment="Bottom" />-->
                                            <!--<TextBlock Text="{Binding ItemCount}" FontSize="22" Foreground="Green" FontWeight="Bold" FontStyle="Italic" Margin="10,0" VerticalAlignment="Bottom" />
                                            <TextBlock Text=" item(s)" FontSize="22" Foreground="Silver" FontStyle="Italic" VerticalAlignment="Bottom" />-->
                                        </StackPanel>
                                    </Expander.Header>
                                    <ItemsPresenter />
                                </Expander>
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                </Style>
            </groupstyle.ContainerStyle>
        </groupstyle>

    </ListView.groupstyle>
    <ListView.ItemTemplate>

        <DataTemplate>
            <Border BorderBrush="Orange" BorderThickness="0,1">
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*"></ColumnDefinition>
                    </Grid.ColumnDefinitions>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="30"></RowDefinition>
                        <!--<RowDefinition Height="22"></RowDefinition>-->
                    </Grid.RowDefinitions>
                    <Label Content="{Binding ReportName}" FontSize="14" Grid.ColumnSpan="2" Grid.Row="0" ></Label>
                    <!--<StackPanel Grid.Row="1" Orientation="Horizontal">
                        <Label Content="Modififed Date:" HorizontalAlignment="Right" FontSize="10" Width="79"></Label>
                        <Label Content="{Binding ModifiedDate}" VerticalAlignment="Center" HorizontalAlignment="Left"  FontSize="10" Width="auto" Height="22"></Label>
                    </StackPanel>-->
                </Grid>
            </Border>
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

ListView项目源是Reports，并且已在AppReportsViewModel上正确填充了它。

如果取消注释此行，则所有报告都将正确分组。唯一的问题是所有标头都是Hello。

<!--<TextBlock Text="Hello" FontWeight="Bold" Foreground="Black" FontSize="22" VerticalAlignment="Bottom" />-->

结果是这样的：组数正确，但是没有出现ReportCategoryTypeNames。