C# Directive to indicate 32-bit or 64-bit build

Question

Is there some sort of C# directive to use when using a development machine (32-bit or 64-bit) that says something to the effect of:

if (32-bit Vista)
    // set a         


        

Answer 1

What I use in my C# code is IntPtr.Size, it equals 4 on 32bit and 8 on 64bit:

string framework = (IntPtr.Size == 8) ? "Framework64" : "Framework";