Desktop Functions:

   Smart Device Functions:

Show Recent Changes
Subscribe (RSS)
Misc. Pages
Helpful Tools
Suggested Reading
Website TODO List
Support Forum
Download Visual Studio Add-In

Terms of Use
Privacy Policy
ceregqueryvalueex (rapi)

rapi is for smart devices, not desktop Windows. Therefore, this information only applies to code using the .NET Compact Framework. To see if information for ceregqueryvalueex in other DLLs exists, click on Find References to the right.

This function retrieves the type and data for a specified value name associated with an open registry key.

C# Signature:

[DllImport("rapi.dll", CharSet=CharSet.Unicode)]
public static extern uint CeRegQueryValueEx(
    uint hKey,
    string lpValueName,
    int lpReserved,
    ref int lpType,
    byte[] lpData,
    ref int lpchData);

User-Defined Types:

uint HKEY_CLASSES_ROOT = 0x80000000;
uint HKEY_CURRENT_USER = 0x80000001;
uint HKEY_LOCAL_MACHINE = 0x80000002;
uint HKEY_USERS = 0x80000003;


function info on msdn at

Tips & Tricks:

Please add some!

Sample Code:

uint key;
uint ret;

int lpType = new int();
byte[] lpData = new Byte[256];
int lpcbData = lpData.Length;

ret = CeRegOpenKeyEx(HKEY_CURRENT_USER,"Software\\TestApp\\Settings",0,0x1,out key);

if(ret == 0)
    ret = CeRegQueryValueEx(key,"MyKey",0,ref lpType, lpData, ref lpcbData);

    if(ret == 0)
        // success, your data in in lpData to be converted


Alternative Managed API:


Please edit this page!

Do you have...

  • helpful tips or sample code to share for using this API in managed code?
  • corrections to the existing content?
  • variations of the signature you want to share?
  • additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).

Access directly from VS:
Terms of Use
Edit This Page
Find References
Show Printable Version