NetMessageBufferSend API...

rogan

Hi all, thanks for reading this message, i hope someone can help me. Althought I´m very familiar with C and Visual Basic i´m totally newbie in C#. I´m developing a little APP that sends pop up windows to registered network users with NetMessageBufferSend API, but I cannot implement it properly on C#, this is the declaration of the API in VB 6 Private Declare Function NetMessageBufferSend Lib "netapi32" (ByVal servername As String, ByVal msgname As String, ByVal fromname As String, ByVal msgbuf As String, ByRef msgbuflen As Long) As Long And this is my APP Code: [DllImport("netapi32.dll")] static extern short NetMessageBufferSend (string servername, string msgname, string fromname, string msgbuf , ref short msgbuflen); And I call the function this way... short success=0; short len=0; string msg = "Hello!"; len=(short)msg.Length; success = NetMessageBufferSend(System.Net.Dns.GetHostName(),System.Net.Dns.GetHostName(), "" ,msg,ref len); for testing purposes. success var returns 123 which is ... Private Const ERROR_INVALID_NAME As Long = 123 I cannot make it work, and i really want to make it run on c#, if someone has a clue, post here. Thanks a bunch for reading this. :)

7 Replies

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spgilmore23y ago
No, that's perfectly helpful! The only questions remaining are, is there a way to set the encoding used by C# interop calls, and what is the encoding it uses by default?
brad 023y ago
This is tangential, but ... according to this article, VB, COM, and Windows NT/2000/XP all use UCS-2 encoding internally: http://www.joelonsoftware.com/articles/Unicode.html
rogan23y ago
mmm, thanks again. I found this link about using the "net" comand functions, but there are no hints about "net send". Well, maybe it helps... http://www.csharphelp.com/archives2/archive439.html
spgilmore23y ago
Yes, I had to convert my null-terminated strings in Delphi to Unicode before making the call, but as far as I understood, every string in C# is unicode. It might require a different encoding, but I don't know much about how to do that, or what encoding to use. I would think UTF-8 or something fairly universal like that, but I may be way off here...
rogan23y ago
i have read that the string vars you use in the function call must be on unicode format... In visual basic you can convert them to unicode using strconv(var,vbunicode), but i don´t know how to do it in C#. Any clue?
rogan23y ago
thanks a lot, i´ll give it a shot. :)
spgilmore23y ago
I couldn't get it to work, either, but I get result 1113. I even tried using unsafe code so pass the correct parameters (char* and such). No luck. Instead, I wrote a DLL in Delphi that does this perfectly, then I call THAT entrypoint instead. Maybe you could do the same thing with Visual C++. Then, you may be able to write a .net assembly instead of a DLL, which is better anyway.