Can't get combobox to bind to a custom object in a GridView

[Chris Kirkman]

I've tried to put this question in the forum but the page keeps disappearing after I click "submit", so here I am...

I have a 3 column GridView and the GridViewComboBoxColumn is not binding correctly.  I've set the following for the grid.

1. DisplayMember = Color
2. ValueMember = Id 
3. DataType =  System.ComponentModel.BindingList`1[TelerikGridViewTests.Models.ColorViewModel]

When I run the application I see "System.ComponentModel.BindingList`1[TelerikGridViewTests.Models.ColorViewModel]" instead of the object within my model.  For my other 2 columns in the grid (a decimal and a string) those are displayed just fine. 

 

Here is my model code... 

using System.ComponentModel;

namespace TelerikGridViewTests.Models
{
    public class CarsViewModel : ViewModelBase
    {
        public CarsViewModel()
        {
            _cars = new BindingList<CarViewModel>();

            _cars.Add(new CarViewModel()
            {
                Id = 0m,
                Description = "Ford",
                Colors = new ColorsViewModel().Colors,
            });

            _cars.Add(new CarViewModel()
            {
                Id = 1m,
                Description = "Chevy",
                Colors = new ColorsViewModel().Colors,
            });

            _cars.Add(new CarViewModel()
            {
                Id = 2m,
                Description = "Dodge",
                Colors = new ColorsViewModel().Colors,
            });
        }

        BindingList<CarViewModel> _cars;
        public BindingList<CarViewModel> Cars { get { return _cars; } set { _cars = value; } }
    }

    public class CarViewModel : ViewModelBase
    {
        public decimal Id { get; set; }
        public string Description { get; set; }

        BindingList<ColorViewModel> _colors;
        public BindingList<ColorViewModel> Colors
        {
            get { return _colors; }
            set { _colors = value; }
        }
    }

    public class ColorsViewModel : ViewModelBase
    {
        public ColorsViewModel()
        {
            Colors = new BindingList<ColorViewModel>();

            Colors.Add(new ColorViewModel()
            {
                Id = 1,
                Color = "Blue",
            });
            Colors.Add(new ColorViewModel()
            {
                Id = 2,
                Color = "Red",
            });
            Colors.Add(new ColorViewModel()
            {
                Id = 3,
                Color = "Green",
            });
            Colors.Add(new ColorViewModel()
            {
                Id = 4,
                Color = "Yellow",
            });
        }

        public BindingList<ColorViewModel> Colors { get; set; }
    }

    public class ColorViewModel : ViewModelBase
    {
        public int Id { get; set; }
        public string Color { get; set; }
    }
}

 

and code which binds the model..

using System.ComponentModel;
using System.Windows.Forms;
using TelerikGridViewTests.Models;

namespace TelerikGridViewTests
{
    public partial class Form1 : Form
    {        
        public Form1()
        {
            InitializeComponent();

            BindingList<CarViewModel> _cars = new CarsViewModel().Cars;
            radGridView1.DataSource = _cars;
        }
    }
}

[Dess | Tech Support Engineer, Principal]

Hello, Chris,

Thank you for writing.  

The provided sample project is greatly appreciated. The Id and Description properties are of simple types but the Colors property is a BindingList of custom objects. In this case RadGridView will show the type. Note that GridViewComboBoxColumn needs a DataSource collection and the cells should store the values specified as ValueMember of the column. The following help article demonstrates how to setup properly the GridViewComboBoxColumn: https://docs.telerik.com/devtools/winforms/gridview/columns/column-types/gridviewcomboboxcolumn

Alternatively, you can use a GridViewTextBoxColumn and handle the EditorRequired event where you can specify what editor to be used. Here is a sample code snippet: 

public Form1()
  {
      InitializeComponent();

      BindingList<CarViewModel> _cars = new CarsViewModel().Cars;
      radGridView1.DataSource = _cars;

      this.radGridView1.Columns[2].IsVisible = false;
      GridViewTextBoxColumn col = new GridViewTextBoxColumn("MyColumn");
      this.radGridView1.Columns.Add(col);
      this.radGridView1.EditorRequired += radGridView1_EditorRequired;
  }

  private void radGridView1_EditorRequired(object sender, EditorRequiredEventArgs e)
  {
      if (this.radGridView1.CurrentColumn.Name == "MyColumn")
      {
          RadDropDownListEditor ddl = new RadDropDownListEditor();
          RadDropDownListEditorElement element = ddl.EditorElement as RadDropDownListEditorElement;
          element.DataSource = ((CarViewModel)this.radGridView1.CurrentRow.DataBoundItem).Colors;
          element.DisplayMember = "Color";
          e.Editor = ddl;
      }
  }

I hope this information helps. Should you have further questions I would be glad to help. 
 
 Regards,
Dess
Progress Telerik

[Chris Kirkman]

The 2nd method you provided...using the EditorRequired event allowed me to get it to work as I needed.  Thanks.  You might want to push this info to the forums, it wasn't entirely straightforward even with the documentation.

[Dess | Tech Support Engineer, Principal]

Hello, Chris,  

Thank you for writing back. 

I am glad that the provided solution was useful for your case. I am converting this support ticket into a forum thread in order the community to benefit from it. 

If you have any additional questions, please let me know. 

 Regards,
Dess
Progress Telerik