How to handle a NULL value in reader.GetByte(x)?

Question

I've got the following block of code:

//Check to see if the Unique_ID is 10 or 11 and process accordingly
//10 = Both boxes, 11 = Rework only
if (reader.GetByte(16) == 10)
{
   int ES = Convert.ToInt32(reader["ESCALATED"]);
   if (ES == 0)
   {
      chkEscalated.Checked = false;
   }
   else
   {
      chkEscalated.Checked = true;
      chkEscalated.Visible = true;
      lblEscalated.Visible = true;
      chkRework.Visible = true;
      lblRework.Visible = true;
    }
}
else if (reader.GetByte(16) == 11)
{
}
else
{
}

The problem I have is, sometimes, reader.GetByte(16) is NULL. And when that happens, I get an error:

Data is Null. This method or property cannot be called on Null values.

I'm still somewhat of a novice, so I'm sure there's something obvious that I'm missing, but I just can't find it.

Answer 1

Use IsDBNull method :

//Check to see if the Unique_ID is 10 or 11 and process accordingly
//10 = Both boxes, 11 = Rework only
if (reader.IsDBNull(16))
{
   //Add here your code to handle null value
}
else
{
   //Use a switch to read the value only one time
   switch (reader.GetByte(16))
   {
     case 10:
       int ES = Convert.ToInt32(reader["ESCALATED"]);
       if (ES == 0)
       {
          chkEscalated.Checked = false;
       }
       else
       {
          chkEscalated.Checked = true;
          chkEscalated.Visible = true;
          lblEscalated.Visible = true;
          chkRework.Visible = true;
          lblRework.Visible = true;
        }
        break;

      case 11:
        break;

      default:
        break;
   }
}