Binding GridView to DataTable which contains an Enumeration

[Nils]

Hey guys,
I'm trying to bind a GridView to a DataTable which contains DataColumns of Type Boolean, String, Int32 and an Enumeration. When I bind it using AutoGenerateColumns = true the column containing the enum-values shows their int representation. I expected it to show as a dropdown like the standard DataGridView does.

Afterwards I tried to create the GridViewColumns myself but I can't figure out how to use the Enum as a DataSource for the GridViewComboBoxColumn. Here is my code:

GridViewComboBoxColumn col5 = new GridViewComboBoxColumn("ResultType");
col5.DataSource = Enum.GetValues(typeof(EnumResultType));
col5.ValueMember = "???";
col5.DisplayMember = "???";
dgvDisciplines.MasterGridViewTemplate.Columns.Add(col5);

Is this the right way to specify the DataSource? How do I need to specify the ValueMember and Displaymember?

The DropDown in the ComboBoxEditor shows the right (string) Values but the int-values of the rows aren't converted to that String-Representation.

If needed, here is the code of the enumeration:

public enum EnumResultType
    {
        Maximum,
        Minimum,
        Summe,
        Durchschnitt
    }

Any hints?

Kind regards,
Nils

[Victor]

Hello Nils,

Thanks for writing.

I suggest wrapping the enum in a class as demonstrated below:

public enum EnumResultType
{
     Minimum, Maximum, Summe, Durchschnitt
}

class EnumWrapper
{
     public int ID
     {
         get;
         set;
     }

     public string Name
     {
         get { return Enum.GetName(typeof(EnumResultType), ID); }
         set { ID = (int)Enum.Parse(typeof(EnumResultType), value); }
     }

     public EnumWrapper(EnumResultType value)
     {
          ID = (int)value;
     }
}

Then, follow these steps:

1. Create a DataTable and a column of type int add to it.
2. Set the grid DataSource to the DataTable
3. Create a GridViewComboBoxColumn and bind it to a list of objects of the class above
4. Add the column to the grid Columns collection.

Here is some sample code:

DataTable table = new DataTable();
table.Columns.Add("Value", typeof(int));

table.Rows.Add((int)MyEnum.Maximum);
table.Rows.Add((int)MyEnum.Minimum);
table.Rows.Add((int)MyEnum.Durchschnitt);

List<EnumWrapper> list = new List<EnumWrapper>();
list.Add(new EnumWrapper(MyEnum.Durchschnitt));
list.Add(new EnumWrapper(MyEnum.Maximum));
list.Add(new EnumWrapper(MyEnum.Minimum));
list.Add(new EnumWrapper(MyEnum.Summe));

GridViewComboBoxColumn col = new GridViewComboBoxColumn("Value");
col.DataSource = list;
col.DisplayMember = "Name";
col.ValueMember = "ID";

radGridView1.MasterGridViewTemplate.AutoGenerateColumns = false;
radGridView1.Columns.Add(col);
radGridView1.DataSource = table;

Please contact us if you need further assistance.

Regards,
Victor
the Telerik team
Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[Nils]

Hi Victor,

thanks. I thought there is an easier method of databinding to a column of an Enum-Type. But your answer gave me the push to the right direction. Because there is more than one column of this kind I wrote a generic class which could be used for every kind of enum. Hopefully it is helpful for anyone who covers the same problem.

Here is my EnumWrapper-class:

class EnumWrapper<t>
    {
        public int ID
        {
            get;
            set;
        }

        public string Name
        {
            get { return Enum.GetName(typeof(t), ID); }
            set { ID = (int)Enum.Parse(typeof(t), value); }
        }

        public EnumWrapper(t value)
        {
            ID = (int)Enum.Parse(typeof(t), value.ToString());
        }

        public static List<EnumWrapper<t>> EnumToList<t>()
        {

            Type enumType = typeof(t);

            if (enumType.BaseType != typeof(Enum))
                throw new ArgumentException("T must be of type System.Enum");

            Array enumValArray = Enum.GetValues(enumType);
            List<EnumWrapper<t>> enumValList = new List<EnumWrapper<t>>();
            foreach (int val in enumValArray)
            {
                enumValList.Add(new EnumWrapper<t>((t)Enum.Parse(enumType, val.ToString())));
            }
            return enumValList;
        }
    }

And this is the way to use this class as a DataSource for a GridViewcomboBoxColumn:

GridViewComboBoxColumn col5 = new GridViewComboBoxColumn("ResultType");
col5.DataSource = EnumWrapper<EnumResultType>.EnumToList<EnumResultType>();
col5.ValueMember = "ID";
col5.DisplayMember = "Name";
dgvDisciplines.MasterGridViewTemplate.Columns.Add(col5);

Nothing more to do :) Thanks!

Kind regards,
Nils

[Victor]

Hi Nils,

Thanks for sharing your solution with the community. We highly appreciate it.
Happy coding! :)

Greetings,
Victor
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[Michael Bakker]

Thanks for sharing your code. It's still relevant after 5 years!

[Bilbo]

This code is still relevant near the end of 2023.... instantiating a DataGridViewComboBoxColumn is a tiny bit different than the old GridViewComboBoxColumn, but everything else still compiles and works today!