To provide file opening support, the .NET Framework provides the OpenFileDialog class which is derived from the FileDialog class that in fact provides most of its functionality. The easiest way to use it is to click the OpenFileDialog button from the Toolbox and click the form. You can click anywhere on the form because the OpenFileDialog object would not be seen at run time. After placing it on the form, you can use the Properties window to configure it.

If you prefer to dynamically create an Open dialog box, declare a variable of type OpenFileDialog and use the new operator to allocate memory using its default constructor. Here is an example:

using System;
using System.Windows.Forms;

public class Exercise : Form
{
    private OpenFileDialog  ofd;

    public Exercise()
    {
	InitializeComponent();
    }

    void InitializeComponent()
    {
        ofd = new OpenFileDialog();
    }
}

public class Program
{
    public static int Main()
    {
        Application.Run(new Exercise());

        return 0;
    }
}