Question

I have the following code that I’m trying to use to populate a ComboBox, but it’s not showing the actual text of the objects that I’m adding.

internal partial class SortBox : UserControl {
    private Field[] FieldReferences
    ...
    internal Field[] Fields {
        ...
        set {
            this.FieldReferences = value;
            this.cboFields.Items.Clear();
            string NoneString = "(none)";
            this.cboFields.Items.Add(NoneString);
            this.cboFields.SelectedItem = NoneString;
            foreach (Field Field in this.FieldReferences) {
                MessageBox.Show(Field.ToString()); // <- This displays what I want displayed perfectly.
                this.cboFields.Items.Add(Field);
            }
        }
    }
    ...
}

public partial class Field : UserControl {
    protected string LabelValue;
    ...
    public override string ToString() {
        return this.LabelValue;
    }
}

Here’s what I’m getting; they’re all blank:

What am I doing wrong?

EDIT: Apparently, my Field class is inheriting from UserControl. I’ve done some tests, and it apparently has something to do with the fact that the class inherits from System.ComponentModel.Component.

Answer 1

If I am reading your code right, you are trying to put a usercontrol inside a combobox.

Overriding the ToString won’t work when you do that, so to make the code that you currently have work, just change the DrawMode:

This works:

cboFields.DrawMode = DrawMode.OwnerDrawFixed;
cboFields.DrawItem += new DrawItemEventHandler(cboFields_DrawItem);

private void cboFields_DrawItem(object sender, DrawItemEventArgs e)
{
  e.DrawBackground();
  if (e.Index > -1)
    e.Graphics.DrawString(cboFields.Items[e.Index].ToString(), e.Font, Brushes.Black, e.Bounds);
}

But I have to say, I don’t know if putting a UserControl inside a ComboBox collection is the best way to do this. I would seriously consider refactoring that differently.