C#

string[] files = (string[])e.Data.GetData(DataFormats.FileDrop);
foreach (string file in files)
{
    try
    {
    if (!listBox1.Items.Contains(file))
    listBox1.Items.Add(file);
    listBox1.SelectedIndex = listBox1.Items.Count - 1;
    }
    catch (Exception ex)
    {
        MessageBox.Show("Cannot find "+file, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
    }
}

imran_Shaikh wrote:

What is constructor

imran_Shaikh wrote:

how to use it

public class MyCoolClass
{
    public MyCoolClass()
    {
        // This is a constructor. It is just a special type of method.
        // Initialise the new instance of the class here
    }
}
 
class Program
{
    static void Main()
    {
        MyCoolClass aCoolObject = new MyCoolClass();
    }
}