if (txtmessage.Text.Length > 0)
   {   
       txtcount.Text = txtmessage.Text.Length.ToString();  
   }  

  else  
   txtcount.Text = Convert.ToString(0);

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace counttextusingevent
{    public partial class Form1 : Form  
  {        public Form1()  
      {       
     InitializeComponent();    
    }     
 private void txtmessage_TextChanged(object sender, EventArgs e)           {          
          if (txtmessage.Text.Length > 0)  
           {     
                 txtcount.Text = txtmessage.Text.Length.ToString();       
          }      
       else       
         txtcount.Text = Convert.ToString(0);  
                }  
  }
}