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.

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

See Also

MsiDeterminePatchSequence

MsiDetermineApplicablePatches

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Build date: 8/13/2009