Dear Joe,

The CellParsing event occurs when a cell leaves edit mode if the cell value
has been modified.
When the form loads, none of the cells is in edit mode, so no CellParsing
event occurs, the values in the cells are still of string type, but the
desired type is MyEnum, so the "value not valid" exception throws.

For binding Enum types, then best way is calling the Enum.GetValues()
method to retrieve an array of values of the constants in a the
enumeration, then use this array as the data source of the
DataGridViewComboBoxColumn, something like this:

      private void Form1_Load(object sender, EventArgs e)
       {
           DataGridViewComboBoxColumn column1 = new
DataGridViewComboBoxColumn();

           column1.DataPropertyName = "TheEnum";
           column1.DataSource = Enum.GetValues(typeof(MyEnum));

           dataGridView1.Columns.Add(column1);

           MyListClass listClass = new MyListClass();

           listClass.Add(new MyClass("a", MyEnum.Item3));
           listClass.Add(new MyClass("b", MyEnum.Item2));
           listClass.Add(new MyClass("c", MyEnum.Item1));

           dataGridView1.DataSource = listClass;
       }

Through this approach, we can avoid the manually parsing and formatting
stuff, which means, we don't need to handle the CellParsing and
CellFormating events at all in this scenario.

[Documents for your information]

DataGridView.CellParsing Event
http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.ce
llparsing.aspx

Enum.GetValues Method
http://msdn.microsoft.com/en-us/library/system.enum.getvalues.aspx

If you need further help on this, please don't hesitate to let me know.

Have a nice day!

Sincerely,
Zhi-Xin Ye
Microsoft Managed Newsgroup Support Team

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