How to bind list of object to DataGrid in WPF

Question

This is my code behind:

public partial class MainWindow : INotifyPropertyChanged
{
    private List<Word> _words;

    public List<Word> Words
    {
        get => _words;
        set
        {
            _words = value;
            OnPropertyChanged("Words");
        }
    }

    public MainWindow()
    {
        InitializeComponent();

        MeaningGroup group1 = new MeaningGroup()
        {
            Synonyms = new List<string> {"synonym1", "synonym2", "synonym3"},
            Acronyms = new List<string> {"acronym1", "acronym2"}
        };

        MeaningGroup group2 = new MeaningGroup()
        {
            Synonyms = new List<string> { "synonym1"},
            Acronyms = new List<string> { "acronym1", "acronym2", "acronym3" }
        };

        MeaningGroup group3 = new MeaningGroup()
        {
            Synonyms = new List<string> { "synonym1", "synonym2" },
            Acronyms = new List<string> { }
        };

        MeaningGroup group4 = new MeaningGroup()
        {
            Synonyms = new List<string> { "synonym1" },
            Acronyms = new List<string> { "acronym1", "acronym2", "acronym3","acronym4" }
        };

        Word word1 = new Word() {Name = "word1",MeaningGroups = new List<MeaningGroup>() {group1, group2}};
        Word word2 = new Word() { Name = "word2", MeaningGroups = new List<MeaningGroup>() { group3, group4 } };
        Word word3 = new Word() { Name = "word3", MeaningGroups = new List<MeaningGroup>() { group1, group2,group4 } };
        Word word4 = new Word() { Name = "word4", MeaningGroups = new List<MeaningGroup>() { group3 } };

        Words = new List<Word> {word1, word2, word3, word4};

    }

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

public class Word
{
    public String Name { get; set; }
    public List<MeaningGroup> MeaningGroups { get; set; }

}

public class MeaningGroup
{
    public List<string> Synonyms { get; set; }
    public List<string> Acronyms { get; set; }
}

And this is MainWindow.xaml code:

<Window x:Class="WpfApp4.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:WpfApp4"
    DataContext="{Binding RelativeSource={RelativeSource Self}}"
    mc:Ignorable="d"
    Title="MainWindow" Height="450" Width="800">
<Grid>
    <DataGrid ItemsSource="{Binding Words}" AutoGenerateColumns="False">
        <DataGrid.Columns>
            <DataGridTextColumn Header="Name" Binding="{Binding Name}"/>
            <DataGridTextColumn Header="Synonym and acronyms">
               <!-- How binding? -->
            </DataGridTextColumn>
        </DataGrid.Columns>
    </DataGrid>
</Grid>

I want to bind data objects like this:

Answer 1

I don't quite understand what you mean, but if you want to bind properties to columns, you can do this:

<DataGrid ItemsSource="{Binding Words}">
   <DataGrid.Columns>
     <DataGridTextColumn Header="Name" Binding="{Binding Name}"/>
   </DataGrid.Columns>
</DataGrid>

Now the "Name" of each element will be added to this column. But if you want to add more than one property to a column, you'll have to add DataGridTemplateColumn :

<DataGrid ItemsSource="{Binding Words}">       
   <DataGrid.Columns>
      <DataGridTextColumn Header="Name" Binding="{Binding Name}"/>
      <DataGridTemplateColumn Header="Synonyms and Acronyms">
         <DataGridTemplateColumn.CellTemplate>
            <DataTemplate>
               <StackPanel>
                     //There will be all logic. For example
                     //<TextBlock Text="{Binding Synonyms}"/>
                     //<TextBlock Text="{Binding Acronyms}"/>
               </StackPanel>
            </DataTemplate>
         </DataGridTemplateColumn.CellTemplate>
      </DataGridTemplateColumn>
   </DataGrid.Columns>
</DataGrid>

But sorry, I don't know what would happen if the column is to pass a collection of strings (as in your example). And I'm sorry if I misunderstood you

Answer 2

Your updated code still has a binding mistake, you need to add this to the bottom of your constructor:

    this.DataContext = this;

The main problem with the code you've posted is that you're trying to merge your Synonym and Acronym arrays into a single list, which is really something that should be done before passing the data to your view layer. I'll use a converter to do this task after-the-fact, but keep in mind that's it's something you should probably fix up later.

In any case what you're trying to achieve is relatively straightforward. Use a DataGridTemplateColumn to declare a custom column type and set its content to an ItemsControl (its default panel is a vertical StackPanel). Each element of the stack panel is a MeaningGroup , so just use another ItemsControl to render your tags, and set its ItemsPanelTemplate to be a horizontal layout instead (I've used a WrapPanel). Put all that together and you get this:

<Window.Resources>

    <behaviors:ListUnionConverter x:Key="ListUnionConverter" />

    <DataTemplate x:Key="TagTemplate">
        <Border BorderBrush="Black" BorderThickness="1" CornerRadius="5" Margin="5" Padding="5">
            <TextBlock Text="{Binding}" />
        </Border>
    </DataTemplate>

    <DataTemplate x:Key="TagListTemplate">
        <ItemsControl ItemTemplate="{StaticResource TagTemplate}">
            <ItemsControl.ItemsSource>
                <MultiBinding Converter="{StaticResource ListUnionConverter}">
                    <Binding Path="Synonyms" />
                    <Binding Path="Acronyms" />
                </MultiBinding>
            </ItemsControl.ItemsSource>
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <WrapPanel />
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
        </ItemsControl>
    </DataTemplate>

    <DataTemplate x:Key="CellTemplate">
        <ItemsControl ItemsSource="{Binding MeaningGroups}" ItemTemplate="{StaticResource TagListTemplate}" />
    </DataTemplate>

</Window.Resources>

<Grid>
    <DataGrid ItemsSource="{Binding Words}" AutoGenerateColumns="False">
        <DataGrid.Columns>
            <DataGridTextColumn Header="Name" Binding="{Binding Name}"/>
            <DataGridTemplateColumn Header="Synonym and acronyms" IsReadOnly="True" CellTemplate="{StaticResource CellTemplate}" />
        </DataGrid.Columns>
    </DataGrid>
</Grid>

You'll also need the code for the converter that I'm using to join the Synonymns and Acronyms into a single list. Again, you should either replace this with something more robust or, preferably, fix up your data structures to better match the view requirements:

Result:

public class ListUnionConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        return (values[0] as IEnumerable<string>).Concat(values[1] as IEnumerable<string>).ToArray();
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

UPDATE: I just noticed the requirement for the colors to be different. You could also use a converter to do that if you absolutely had to, but that's a really messy solution. The correct way to implement this is with an intermediate view model and with both synonyms and acronyms merged into a single list.

Answer 3

the answer below solves this problem, but I will suggest another way. As said above, first you need to add DataContext = this in your code-behide. Then just change the xaml markup as follows:

     <Grid>
        <DataGrid ItemsSource="{Binding Words}" AutoGenerateColumns="False">
            <DataGrid.Columns>
                <DataGridTextColumn Header="Name" Binding="{Binding Name}"/>
                <DataGridTemplateColumn Header="Synonym and acronyms">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <StackPanel>
                                <ItemsControl ItemsSource="{Binding MeaningGroups}">
                                    <ItemsControl.ItemTemplate>
                                        <DataTemplate>
                                            <StackPanel Orientation="Horizontal">
                                                <ItemsControl ItemsSource="{Binding Synonyms}">
                                                    <ItemsControl.ItemsPanel>
                                                        <ItemsPanelTemplate>
                                                            <WrapPanel/>
                                                        </ItemsPanelTemplate>
                                                    </ItemsControl.ItemsPanel>
                                                    <ItemsControl.ItemTemplate>
                                                        <DataTemplate>
                                                            <Border BorderThickness="1" BorderBrush="Black" CornerRadius="5" Margin="5 5 0 0">
                                                            <TextBlock Margin="3" Text="{Binding}"/>
                                                            </Border>
                                                        </DataTemplate>
                                                    </ItemsControl.ItemTemplate>
                                                </ItemsControl>
                                                <ItemsControl ItemsSource="{Binding Acronyms}">
                                                    <ItemsControl.ItemsPanel>
                                                        <ItemsPanelTemplate>
                                                            <WrapPanel/>
                                                        </ItemsPanelTemplate>
                                                    </ItemsControl.ItemsPanel>
                                                    <ItemsControl.ItemTemplate>
                                                        <DataTemplate>
                                                            <Border BorderThickness="1" BorderBrush="Black" CornerRadius="5" Background="Red" Margin="5 5 0 0">
                                                            <TextBlock Margin="3" Text="{Binding}"/>
                                                            </Border>
                                                        </DataTemplate>
                                                    </ItemsControl.ItemTemplate>
                                                </ItemsControl>
                                            </StackPanel>
                                        </DataTemplate>
                                    </ItemsControl.ItemTemplate>
                                </ItemsControl>
                            </StackPanel>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>
            </DataGrid.Columns>
        </DataGrid>
    </Grid>

As a result, we will get