How to programmatically add an element in DataTemplate in a DataGrid

Question

I have a WINUI3 project in which I need to add an element, CheckBox inside a

CheckBox->DataTemplate->DataGridTemplateColumn.CellTemplate->DataGrid

While my DataGrid is defined in Xaml, I need to add the CheckBox inside DataTemplate progmatically using C#. For reasons unknown to me, I dont understand why its so complicated while its easily done in Xaml,in C# there seems to be no way.

private void CreateDataTableForBowlers()
{
    allBowlers.Columns.Clear();
    DataGridTextColumn column = new DataGridTextColumn() { Header = "Name", Binding = new Binding() { Path = new PropertyPath("Name") } };
    column.FontSize = 10;

    DataGridTemplateColumn dataGridTemplateColumn = new();
    dataGridTemplateColumn.Header = "Select Two";

    DataTemplate dataTemplate = new DataTemplate();
    dataGridTemplateColumn.CellTemplate = dataTemplate;

    CheckBox checkBox = new CheckBox();
    checkBox.SetBinding(CheckBox.IsCheckedProperty, new Binding() { Path = new PropertyPath("isBowling") });

    /*
     * Need to add checkBox to dataTemplate here
     * 
     */

    allBowlers.Columns.Add(dataGridTemplateColumn);
    allBowlers.Columns.Add(column);          
}

The Corresponding Xaml that I have is (For reference)

<controls:DataGridTemplateColumn Header="Select Two">
    <controls:DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <CheckBox IsChecked="{Binding GetBowling ,Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Checked="CheckBox_Checked" />
        </DataTemplate>
    </controls:DataGridTemplateColumn.CellTemplate>
</controls:DataGridTemplateColumn>

I even tried XamlReader.Load, for above XAML part which always ends in crashing. Anyone what am I missing in doing it in C#?

UPDATE

I had used XamlReader.Load earlier and also as suggested by @Andrew KeepCoding but didnt work. I cant use string literals like """ as I am using Win10. So my code for XamlReader.Load looks like this

   private void CreateDataTableForBowlers()
 {

allBowlers.Columns.Clear();
   DataGridTextColumn column = new DataGridTextColumn() { Header = "Name", Binding = new Binding() { Path = new PropertyPath("Name") } };
   column.FontSize = 10;
   DataGridTemplateColumn dataGridTemplateColumn = new();
   dataGridTemplateColumn.Header = "Select Two";        
   

   //CheckBox checkBox = new CheckBox();
   //checkBox.SetBinding(CheckBox.IsCheckedProperty, new Binding() { Path = new PropertyPath("isBowling") });

   string xaml = "<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'> <CheckBox IsChecked='{Binding IsBowling, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}' /></DataTemplate>";

   DataTemplate dataTemplate = new DataTemplate();
   dataTemplate = XamlReader.Load(GetStream(xaml)) as DataTemplate;

   dataGridTemplateColumn.CellTemplate = dataTemplate;

   allBowlers.Columns.Add(dataGridTemplateColumn);
   allBowlers.Columns.Add(column); 
 }

   private Stream GetStream(string input)
   {
       byte[] byteArray = System.Text.Encoding.UTF8.GetBytes(input);
       return new MemoryStream(byteArray);
   }

Answer 1

This should work:

private void CreateDataTableForBowlers()
{
    DataGridControl.Columns.Clear();
        
    DataGridTextColumn textColumn = new()
    {
        Header = "Name",
        Binding = new Binding
        {
            Path = new PropertyPath("Name"),
        }
    };

    DataGridControl.Columns.Add(textColumn);

    DataTemplate? checkBoxTemplate = XamlReader.Load(
        @"
        <DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'>
            <CheckBox
                Content='Is Bowling'
                Checked='CheckBox_Checked'
                IsChecked='{Binding IsBowling, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}'
                IsEnabled='{Binding IsEnabled}' />
        </DataTemplate>
        ") as DataTemplate;

    DataGridTemplateColumn templateColumn = new()
    {
        Header = "Is Bowling",
        CellTemplate = checkBoxTemplate,
    };

    DataGridControl.Columns.Add(templateColumn);
}

And if you need to subscribe to Checked event:

public MainPage()
{
    this.InitializeComponent();
    this.DataGridControl.LoadingRow += DataGridControl_LoadingRow;
}

private void DataGridControl_LoadingRow(object? sender, DataGridRowEventArgs e)
{
    e.Row.Loaded += Row_Loaded;

}

private void Row_Loaded(object sender, RoutedEventArgs e)
{
    if (sender is not DataGridRow row)
    {
        return;
    }

    if (row.FindDescendants()
        .OfType<DataGridCell>()
        .Select(x => x.Content)
        .OfType<CheckBox>()
        .FirstOrDefault() is CheckBox checkBox)
    {
        checkBox.Checked -= CheckBox_Checked;
        checkBox.Checked += CheckBox_Checked;
    }
}

BTW, the FindDescendants() extension method is from the CommunityToolkit.WinUI.UI NuGet package.