How to create DataTemplate in code?

Question

I've seen some example of creating DataTemplate with StackPanel and deprecated FrameworkElementFactory. For the Tenant under Lease section I want to have a DataTemplate with a Grid with two columns and two TextBlocks (one for Name and the other for Phone):

The SelectItem, tenant, is my control and want the following dataTemplate Grid to be its ItemTemplate

var nameBlock = new TextBlock();  
var phoneBlock = new TextBlock();  
Grid.SetColumn(phoneBlock, 1);  
var dataTemplate= new Grid() {  
    ColumnDefinitions = {  
        new ColumnDefinition(),  
        new ColumnDefinition(){Width = GridLength.Auto}  
    },  
    Children = {nameBlock, phoneBlock}  
};  
          
tenant = new SelectItem() {  
    Hint = "Tenant",  
    IsRequired = true,  
    Icon = Icons.Tenant,  
    SelectedValuePath = nameof(Tenant.Id),  
    SearchPath = nameof(Tenant.Name),  
    DisplayPath = nameof(Tenant.Name),  
    ItemTemplate = dataTemplate  
};  

this way it doesn't work!

Answer 1

The deprecated method still works:

var gridFactory = new FrameworkElementFactory(typeof(Grid));
var column1Factory = new FrameworkElementFactory(typeof(ColumnDefinition));
var column2Factory = new FrameworkElementFactory(typeof(ColumnDefinition));
var nameFactory = new FrameworkElementFactory(typeof(TextBlock));
var phoneFactory = new FrameworkElementFactory(typeof(TextBlock));

column1Factory.SetValue(ColumnDefinition.WidthProperty, new GridLength(1, GridUnitType.Star));
column2Factory.SetValue(ColumnDefinition.WidthProperty, new GridLength(1, GridUnitType.Auto));
phoneFactory.SetValue(Grid.ColumnProperty, 1);

nameFactory.SetBinding(TextBlock.TextProperty, new Binding("Name"));
phoneFactory.SetBinding(TextBlock.TextProperty, new Binding("ContactNo"));

gridFactory.AppendChild(column1Factory);
gridFactory.AppendChild(column2Factory);
gridFactory.AppendChild(nameFactory);
gridFactory.AppendChild(phoneFactory);

tenant = new SelectItem() {
    Hint = "Tenant",
    IsRequired = true,
    Icon = Icons.Tenant,
    SelectedValuePath = nameof(Tenant.Id),
    SearchPath = nameof(Tenant.Name),
    //DisplayPath = nameof(Tenant.Name)
    ItemTemplate = new DataTemplate() { VisualTree = gridFactory }
};

BUT boring! It'd be nice if I could do like this:

var nameBlock = new TextBlock();
var phoneBlock = new TextBlock();
Grid.SetColumn(phoneBlock, 1);
var template = new DataTemplate(){ new Grid() {
    ColumnDefinitions = {
        new ColumnDefinition(),
        new ColumnDefinition(){Width = GridLength.Auto}
    },
    Children = { nameBlock, phoneBlock }
};