if (message.IsSetField(55)) { string symbol = message.GetString(55); Console.WriteLine("Symbol: " + symbol); }
if (message.IsSetField(123)) // Check if Tag 123 is set { message.SetString(123, "New Value"); // Set the new value only if Tag 123 is already set }Both of these examples use the QuickFix.dll library which provides the Message class, and define the expected structure of the FIX message.