To lazy to make a tutorial

-what you need
using System.IO; (top of code)
OpenFileDialog (renamed dialog)
TextBox (txtData)


PHP Code:
 txtData.Text "";

            
string strFileLoc "";

            
dialog.Filter "txt files (*.txt)|*.txt|All files (*.*)|*.*";
            
dialog.InitialDirectory "C:"dialog.Title "Open";

            if (
dialog.ShowDialog() == DialogResult.OK)
            {
                
strFileLoc dialog.FileName;

                try
                {
                   
using (StreamReader sr = new StreamReader(strFileLoc))
                    {
                        
string line;
                        while ((
line sr.ReadLine()) != null)
                        {
                            
txtData.Text += line "\r\n";
                        }
                    }
                }
                catch (
Exception ex)
                {
                    
MessageBox.Show("Failed to open document. Maybe it doesn't exist or the data is corrupted?""Error");
                }

           }
           else if (
strFileLoc == String.Empty)
           {
                 return;
           } 
Uses FileDialog to find the .txt file the user wants to open, saves the location in a string, StreamReader opens / reads all info in the .txt file.