Question

We’re constructing a buffer of bytes to send out on a .Net Socket Send() method to some factory equipment so the byte order matters. But I’ve noticed that even when I use “[StructLayout(LayoutKind.Sequential,” the Visual Studio 2010 debugger shows a different sequence than I specify. For example,

  [StructLayout(LayoutKind.Sequential, Pack = 1)]
  public class K_NEWFILEGET_START
  {
      public K_HEADER Header = new K_HEADER();
      [System.Runtime.InteropServices.MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
      public byte[] fileName = new byte[32];
      public globals.INT2_Type crc = new globals.INT2_Type();
  }

then I do a

 K_NEWFILEGET_START msg = new K_NEWFILEGET_START();

In the debugger it shows . . .

-    msg      {xxxxx.yyy.K_NEWFILEGET_START}        
+    crc      {xxxxx.globals.INT2_Type}     
+    fileName {byte[32]}                        
+    Header   {xxxxx.yyy.K_HEADER}

(proprietary stuff xxx’ed out) In this example it’s in the reverse order but I have other examples where the displayed order in the debugger is scrambled in different ways.

If I take it one step further and examine the actual output on the network, using a network sniffer, it seems to be in the correct order I specified, so the debugger seems to be the problem but I’d like to see it correctly. BTW I do have “show raw structure of objects in variables windows” set in the debugger options.
Thanks in advance!

Answer 1

The debugger is showing you the members in alphabetical order.

That’s usually more convenient when debugging large structures withe a lot of stuff in them.