Binary Number in C#

step 1: Syntax While Loop

While (condition)
{
   //Execute Statament
}

step 2: Logic Binary Number

protected void Button1_Click(object sender, EventArgs e)
{
    int intNo = Convert.ToInt32(txtNo.Text.Trim());
    int intBinary;
    string strBinary = "";
    while (intNo != 0)
    {
        intBinary = intNo % 2;
        intNo = intNo / 2;
        strBinary = intBinary + strBinary;
    }
    //strBinary.Reverse();
    lblBinaryNo.Text = strBinary;
}

You can implement while loop concept and modulo and division operation easily.