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.

Answer 3

Your query should be like this in GetEmployees() function.

"SELECT id,(lastname + ' ' + first_name) AS NAME FROM TABLE"

cmbEmployees.DataSource = GetEmployees();
cmbEmployees.DisplayMember = "NAME"; 
cmbEmployees.ValueMember = "id";

Answer 4

in C# 6 create readonly property in your Employee class

public string FullName=>$"{lastname} {firstname}";

then

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

Answer 5

Try one of those approaches:

• new Dictionary with concatenated fields as value - https://stackoverflow.com/a/1006588/1816426
• calculated column - https://stackoverflow.com/a/1006546/1816426

Answer 6

// Declare a class
private class ComboRec
   {
     public string ID { get; set; }
     public string FirstName { get; set; }
     public string LastName { get; set; }
     public string FullName { get; set; }
     public string Department { get; set; }
   }

   

    // Fill the Combo Items
    private void FillMyComboList()
            {
                EmployeesCombo.Items.Clear();
                EmployeesCombo.ValueMember = "ID";
                EmployeesCombo.DisplayMember = "FullName";
    
                MySqlCommand cmd = new MySqlCommand("select id, firstname, lastname, department from employees order by lastname, firstname", MyConnection);
                cmd.Transaction = myTransaction;
                MySqlDataReader rdr = cmd.ExecuteReader();
    
                ComboRec comborec;
    
                while (rdr.Read())
                {
                    comborec = new ComboRec();
                    comborec.ID = rdr["id"].ToString();
                    comborec.FirstName = rdr["firstname"].ToString();
                    comborec.LastName = rdr["lastname"].ToString();
                    comborec.FullName = rdr["lastname"].ToString() + ", " + rdr["firstname"].ToString();
                    comborec.Department = rdr["department"].ToString();
    
                    EmployeesCombo.Items.Add(comborec);
                }
    
                rdr.Close();
            }   
       
       
    // Get the values from combo
    string id = ((ComboRec)EmployeesCombo.SelectedItem).ID);
    string firstname = ((ComboRec)EmployeesCombo.SelectedItem).FirstName);
    string lastname = ((ComboRec)EmployeesCombo.SelectedItem).LastName);
    string fullname = ((ComboRec)EmployeesCombo.SelectedItem).FullName);
    string department = ((ComboRec)EmployeesCombo.SelectedItem).Department);

Answer 7

    public void alldata1()
    {
        var Person= context.Person.Select(s => new { 
            display = s.surName+" "+s.name,
            value = s.studentID
        });
        comboBoxStudentNom.DataSource = Person.ToList();
        comboBoxStudentNom.ValueMember = "value";
        comboBoxStudentNom.DisplayMember = "display";
    }

Answer 8

CREATE VIEW [dbo].[get_view] AS SELECT CONCAT(sell_tb.Name,extra_tb.Name,purchase_tb.Name) AS Name FROM sell_tb FULL JOIN extra_tb ON extra_tb.E_ID = sell_tb.E_ID FULL JOIN purchase_tb ON purchase_tb.S_ID = sell_tb.S_ID;

      private void alldata1()
    {
        conn.Open();
        SqlCommand cmd = conn.CreateCommand();
        cmd.CommandType = CommandType.Text;
        cmd.CommandText = "select * from [get_view]";
        cmd.ExecuteNonQuery();
        DataTable dt = new DataTable();
        SqlDataAdapter sda = new SqlDataAdapter(cmd);
        sda.Fill(dt);
        comboBox1.DataSource = dt;
        comboBox1.DisplayMember = "Name";
        conn.Close();
    }