API for Determining if App is Running on Citrix or Terminal Services [closed]

by

There is an API function that lets you determine whether a specific user session is displayed on the console (locally) or via one the the remoting protocols Citrix ICA (nowadays called HDX) or Microsoft RDP.

Call WTSQuerySessionInformation with 3rd parameter set to WTSClientProtocolType. The function returns:

  • 0 for console sessions
  • 1 for ICA sessions
  • 2 for RDP sessions

Interestingly the return value of 1 is not documented as WTS_PROTOCOL_TYPE_ICA on MSDN (second link above) any more, but as “This value is retained for legacy purposes.”.

Update:

XenDesktop sessions cannot be detected with WTSQuerySessionInformation (it returns 0, meaning Console). If you want a universal solution:

  • Call WTSQuerySessionInformation. If that returns 1 or 2 (ICA or RDP), you are done.
  • If WTSQuerySessionInformation returns 0 (Console), dynamically load wfapi.dll and get the address of WFGetActiveProtocol
  • Call WFGetActiveProtocol with a parameter of WF_CURRENT_SESSION, which is defined as ((DWORD)-1)
  • The return value of WFGetActiveProtocol is the session type. It should be either 0 (Console) or 1 (ICA)

I have described the process in detail here along with a C++ code sample and a working compiled tool that returns the current session’s remoting protocol type.

More Related Contents:

  1. How to call the Magento API from VB.NET
  2. How to use a string variable in a directory path
  3. Drawing Textbox at runtime in VB.net and indexing
  4. How to set variable to a huge number
  5. How can i make my own command to my first console application in VB.NET? [closed]
  6. What is the difference between And and AndAlso in VB.NET?
  7. How can I run code in a background thread and still access the UI?
  8. How to programmatically add controls to a form in VB.NET
  9. SQLite not storing decimals correctly
  10. draw outline for some connected lines
  11. Declare global variables in Visual Studio 2010 and VB.NET
  12. Dynamic button click event handler
  13. Accessing imgUr thru OAuth (uploading to user account)
  14. Option Strict on by default in VB.NET
  15. How to put data containing double-quotes in string variable? [duplicate]
  16. Clickable URL in a Winform Message Box?
  17. Doing math in vb.net like Eval in javascript
  18. Casting DataTypes with DirectCast, CType, TryCast
  19. What is the use of a shared variable in VB.NET?
  20. Function call only works when MessageBox.Show() is included?
  21. VB.NET Function Return
  22. Saving ListBox with Additional information in My.settings
  23. Using colons to put two statements on the same line in Visual Basic [closed]
  24. Why is it not necessary to indicate ByVal/ByRef anymore?
  25. Serilog – Output/Enrich All Messages with MethodName from which log entry was Called
  26. Get the output of a shell Command in VB.net
  27. Why is True equal to -1
  28. How to Generate Combinations of Elements of a List in .NET 4.0
  29. How to run DOS/CMD/Command Prompt commands from VB.NET?
  30. VB6 to VB.net conversion [closed]

Leave a Comment