How to append two field values in combobox display member in C#

Question

In my table, I have a field of firstname and lastname, now what I want is to set firstname and lastname as displaymember in a combobox, but I don't know how to do it.

Something like this

cmbEmployees.DataSource = GetEmployees();
//something like below line which doesn't work
cmbEmployees.DisplayMember = "lastname, first_name";     
cmbEmployees.ValueMember = "id";

How can I achieve this? So that both lastname and firstname will be displayed in the combobox

Answer 1

This example will guide you how to do that without modifying your base class.

First, you can leave your DisplayMember with one property, let's say:

cmbEmployees.DisplayMember = "lastname";

Now, go to your form in a [Design] mode, right click on the ComboBox -> Properties.

In the top of the Properties window, click on Events (lightning icon),

look for Format in the events list below (under Property Changed) and type there some event name, let's say: ComboBoxFormat , and press Enter. You will see this:

private void ComboBoxFormat(object sender, ListControlConvertEventArgs e)
{

}

And now write these following lines inside:

private void ComboBoxFormat(object sender, ListControlConvertEventArgs e)
{
    // Assuming your class called Employee , and Firstname & Lastname are the fields
    string lastname = ((Employee)e.ListItem).Firstname;
    string firstname = ((Employee)e.ListItem).Lastname;
    e.Value = lastname + " " + firstname;
}

That's it ;)

Answer 2

Let's say you had a class like this:

class Person
{
    public string FirstName
    {
        get;
        set;
    }

    public string LastName
    {
        get;
        set;
    }

    public string FullName
    {
        get
        {
            return LastName + ", " + FirstName;
        }
    }

    public Person(string firstname, string lastname)
    {
        FirstName = firstname;
        LastName = lastname;
    }
}

If you don't have a FullName property, just create one in the format you wish to display the name. Then set the DisplayMember equal to FullName.