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RegOpenKeyEx (Windows CE 5.0)

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This function opens the specified key.

A remote application interface (RAPI) version of this function exists, and it is called CeRegOpenKeyEx (RAPI).

LONGRegOpenKeyEx( HKEYhKey, LPCWSTRlpSubKey, DWORDulOptions, REGSAMsamDesired, PHKEYphkResult );


  • hKey
    [in] Handle to a currently open key or any of the following predefined reserved handle values:


    Windows CE does not support the HKEY_CURRENT_CONFIG, HKEY_PERFORMANCE_DATA, or HKEY_DYN_DATA predefined reserved handle values.

  • lpSubKey
    [in] Pointer to a null-terminated string containing the name of the subkey to open. If this parameter is NULL or a pointer to an empty string, the function will open a new handle to the key identified by the hKey parameter. In this case, the function will not close the handles previously opened.

  • ulOptions
    [in] Reserved; set to 0.

  • samDesired
    [in] Not supported; set to 0.

  • phkResult
    [out] Pointer to a variable that receives a handle to the opened key. When you no longer need the returned handle, call the RegCloseKey function to close it.

Return Values

ERROR_SUCCESS indicates success. A nonzero error code defined in Winerror.h indicates failure. To get a generic description of the error, call FormatMessage with the FORMAT_MESSAGE_FROM_SYSTEM flag set. The message resource is optional; therefore, if you call FormatMessage it could fail.


Unlike the RegCreateKeyEx function, the RegOpenKeyEx function does not create the specified key if the key does not exist in the registry.


OS Versions: Windows CE 1.0 and later.
Header: Winreg.h.
Link Library: Coredll.lib.

See Also

RegCreateKeyEx | RegDeleteKey

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