Question

我有一个名为Track的课程：

public class Track
{
    public string Title { get; set; }      
    public List<Artist> Artists { get; set; }

}

此类包含Artist对象列表：

public class Artist
{
    public string Name { get; set; }
}

现在我想将它绑定到WPF中的GridView：

 <ListView x:Name="TracksList" Margin="37,325,33,0" VerticalAlignment="Top" Grid.ColumnSpan="1" MouseDoubleClick="TrackList_MouseDoubleClick" Foreground="#FFDEDEDE" Background="#FF232323">
            <ListView.View>
                <GridView>
                    <GridViewColumn DisplayMemberBinding="{Binding Title}" Width="400px" Header="Titel" />
                    <GridViewColumn DisplayMemberBinding="{Binding Artists}" Width="200px" Header="Artists" />     
                </GridView> 
            </ListView.View>
        </ListView>

我使用Track对象列表来填充这个GridView：

TracksList.ItemsSource = album.TrackCollection;

我想要实现的是在Artists列中显示包含所有艺术家姓名的字符串（例如“Artist 1，Artist 2，Artist 3”）。我得到的是一个字符串，解释该字段包含一个列表。我明白为什么会得到这个结果：我没有告诉绑定如何解析和显示列表。

如何配置绑定，以便在列字段中显示艺术家列表。

Answer 1

你可以使用这样的Binding.Converter：

class ArtistsListConverter : IValueConverter
{
    public object Convert(
        object value, Type targetType, object parameter, CultureInfo culture)
    {
        object result = null;
        var artists = value as IEnumerable<Artist>;

        if (artists != null)
        {
            result = string.Join(", ", artists.Select(a => a.Name));
        }

        return result;
    }

    public object ConvertBack(
        object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotSupportedException();
    }
}

XAML：

<local:ArtistsListConverter x:Key="ArtistsListConverter"/>
...
DisplayMemberBinding="{Binding Artists,
                       Converter={StaticResource ArtistsListConverter}}"

Answer 2

这就是视图模型的原因：

public class TrackViewModel
{
    public TrackViewModel(Track model)
    {
        Title = model.Title;
        Artists = string.Join(", ", model.Artists.Select(a => a.Name));
    }

    public string Title { get; private set; }
    public string Artists { get; private set; }
}

Answer 3

如果你绑定了艺术家列表，转换器实际上只是那个。所以，这是转换器的略微即兴版本。

public class ArtistsToStringConverter : System.Windows.Data.IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        var artists = value as IEnumerable<Artist>;

        if (artists != null)
        {
            var artistNames = from artist in artists select artist.Name;
            return string.Join(", ", artistNames);
        }
        return null;
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

数据绑定：显示字符串列表

3 个答案: