Today i tell how to use open file dialog in our application to open a text file ……

 before you use openfiledialog in your application you put button and text boxYou right following code in button click event.. OpenFileDialog OS = new OpenFileDialog();
           OS.ShowDialog();

           FileStream fs = new FileStream(OS.FileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
           StreamReader sr = new StreamReader(fs);
           sr.BaseStream.Seek(0, SeekOrigin.Begin);
           textBox1.Text = sr.ReadToEnd();
           sr.Close();
           fs.Close();