The MsiExtractPatchXMLData function extracts information from a patch that can be used to determine if the patch applies to a target system. The function returns an XML string that can be provided to MsiDeterminePatchSequence and MsiDetermineApplicablePatches instead of the full patch file. The returned information can be used to determine whether the patch is applicable.

Syntax

C++UINT MsiExtractPatchXMLData(
  __in         LPCTSTR szPatchPath,
  __in         DWORD dwReserved,
  __out_opt    LPTSTR szXMLData,
  __inout_opt  DWORD *pcchXMLData
);

Parameters

szPatchPath [in]

The full path to the patch that is being queried. Pass in as a null-terminated string. This parameter cannot be null.

dwReserved [in]

A reserved argument that must be 0 (zero).

szXMLData [out, optional]

A pointer to a buffer to hold the XML string that contains the extracted patch information. This buffer should be large enough to contain the received information. If the buffer is too small, the function returns ERROR_MORE_DATA and sets *pcchXMLData to the number of TCHAR in the value, not including the terminating NULL character.

If szXMLData is set to NULL and pcchXMLData is set to a valid pointer, the function returns ERROR_SUCCESS and sets *pcchXMLData to the number of TCHAR in the value, not including the terminating NULL character. The function can then be called again to retrieve the value, with szXMLData buffer large enough to contain *pcchXMLData + 1 characters.

pcchXMLData [in, out, optional]

A pointer to a variable that specifies the number of TCHAR in the szXMLData buffer. When the function returns, this parameter is set to the size of the requested value whether or not the function copies the value into the specified buffer. The size is returned as the number of TCHAR in the requested value, not including the terminating null character.

If this parameter is set to NULL, the function returns ERROR_INVALID_PARAMETER.

Return Value

The MsiExtractPatchXMLData function can return the following values.

Return code	Description
ERROR_FUNCTION_FAILED	The function failed in a way that is not identified by any of the return values in this table.
ERROR_INVALID_PARAMETER	An invalid parameter was passed to the function.
ERROR_MORE_DATA	The value does not fit in the provided buffer.
ERROR_PATCH_OPEN_FAILED	The patch file could not be opened.
ERROR_SUCCESS	The function was successful.
ERROR_PATCH_PACKAGE_INVALID	The patch file could not be opened.
ERROR_CALL_NOT_IMPLEMENTED	This error can be returned if MSXML 3.0 is not installed.

 

Remarks

Windows Installer 2.0:  Not supported. This function is available beginning with Windows Installer version 3.0.

The ExtractPatchXMLData method of the Installer object uses the MsiExtractPatchXMLData function.

Requirements

Version	Windows Installer 4.0 or Windows Installer 4.5 on Windows Server 2008 or Windows Vista. Windows Installer 3.0 or later on Windows Server 2003, Windows XP, and Windows 2000. See the Windows Installer Run-Time Requirements for information about the minimum Windows service pack that is required by a Windows Installer version.
Header	Msi.h
Library	Msi.lib
DLL	Msi.dll
Unicode and ANSI names	MsiExtractPatchXMLDataW (Unicode) and MsiExtractPatchXMLDataA (ANSI)

See Also

MsiDeterminePatchSequence

MsiDetermineApplicablePatches

Send comments about this topic to Microsoft

Build date: 8/13/2009