Overriding ToString() and adding to ListBox C#

Question

Can anyone explain this:

public class Test : List<int>
{
    public override string ToString()
    {
        return "My ToString";
    }
}

If I instantiate this and add it to a ListBox control on a Windows Form, it displays "Collection" rather than "My ToString".

Test test = new Test();
listBox1.Items.Add(test);

I thought the add to Items would just call my class's ToString(). The following works as expected of course

MessageBox.Show(test.ToString());

Answer 1

For that to work you have to disable formatting:

listBox1.FormattingEnabled = false;

It looks like if formatting is enabled, its doing some magic tricks and the result is not always what it should be...

Answer 2

Set the DisplayMember on the ListBox to the property of the Test type.

listBox1.DisplayMember = "Name";

To solve your problem, add a Property called "Name" to Type and in the getter call ToString.

public class Test : List<Int32>
{
    public String Name { get { return this.ToString(); } }

    public override string ToString()
    {
        return "Test";
    }
}