How can I save the correct ValueMember of a ComboBox to the entities/db? My Winform has ComboBoxes that take Values from Entities of a Lookup Data tabel, as in the following code:
private void FillComboBoxes()
{
chargedToComboBox.Invalidate();
ModelCS ctx = new ModelCS();
var query1 = from a in ctx.LuDatas
where a.Category == "Charged To" && a.IsActive == true
select new { LuValueMember = a.LuValueMember,
LuDisplayMember = a.LuDisplayMember };
var chargedTo = query1.ToList();
chargedToComboBox.DataSource = chargedTo;
chargedToComboBox.DisplayMember = "LuDisplayMember";
chargedToComboBox.ValueMember = "LuValueMember";
string ch = chargedToComboBox.SelectedValue.ToString();
MessageBox.Show(ch); // variable ch shows the CORRECT
// ValueMember
chargedToTextBox.Text = ch; // variable ch show the UNDESIRABLE
// DisplayMember
this.Refresh();
}
On SaveChanges() I get the following error: 'System.Data.Entity.Validation.DbEntityValidationException' occurred in EntityFramework.dll
To find out what is happening, I added a TextBox to the form, and attempted to store in the what I thought was the ComboBox.ValueMember. To do this, I stored the the ComboBox.SelectedValue in a variable (ch) and and stored this variable in the TextBox.Text. What shows up in the TextBox.Text is the DisplayMember of the Combo, not the ValueMember.
To test why, I added a MessageBox to the code to see the vaslue of 'ch'; it shows the corresct value of the ValueMember.
How can it be that in the MessageBox 'ch' has one value and in the TextBox.Text it has another?
All I wanted was to extract a lookup list from the LuData entities, show the choices by name in the ComboBox and store the value by a code in the database.
