Hi ROHIT,
I have created sample code which full-fill your requirement.
C#
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
DataTable dt = new DataTable();
dt.Columns.Add("Title", typeof(string));
dt.Rows.Add("Customers");
dt.Rows.Add("Employees");
dt.Rows.Add("Orders");
DataRow dr = dt.NewRow();
dr["Title"] = "Select";
dt.Rows.InsertAt(dr, 0);
comboBox1.DataSource = dt;
comboBox1.DisplayMember = "Title";
comboBox1.ValueMember = "Title";
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
if (comboBox1.SelectedValue.ToString() == "Customers")
{
if (Application.OpenForms.OfType<Customers>().Count() == 1)
Application.OpenForms.OfType<Customers>().First().Close();
Customers frm = new Customers();
frm.Show();
}
else if (comboBox1.SelectedValue.ToString() == "Employees")
{
if (Application.OpenForms.OfType<Employees>().Count() == 1)
Application.OpenForms.OfType<Employees>().First().Close();
Employees frm = new Employees();
frm.Show();
}
else if (comboBox1.SelectedValue.ToString() == "Orders")
{
if (Application.OpenForms.OfType<Orders>().Count() == 1)
Application.OpenForms.OfType<Orders>().First().Close();
Orders frm = new Orders();
frm.Show();
}
}
}
Screenshot
