GetClassFileOrMime function

Gets the CLSID of the object to instantiate for the specified file.

Syntax

HRESULT GetClassFileOrMime(
             LPBC    pBC,
             LPCWSTR szFilename,
             LPVOID  pBuffer,
             DWORD   cbSize,
             LPCWSTR szMime,
  _Reserved_ DWORD   dwReserved,
             CLSID   *pclsid
);

Parameters

• pBC
  A pointer to a bind context that can affect the mapping to a CLSID. This parameter is usually NULL. It can be used to override system CLSID mappings when it is used with RegisterMediaTypeClass.

• szFilename
  A pointer to a string variable that contains the file name. Can be set to NULL.

• pBuffer
  A pointer to a buffer that contains data from the beginning of the file. Can be set to NULL.

• cbSize
  An unsigned long integer value that contains the size of pBuffer.

• szMime
  A pointer to a string variable that contains the MIME type of the file. Can be set to NULL.

• dwReserved
  Reserved. Must be set to 0.

• pclsid
  A pointer to a CLSID that receives the CLSID of the object to instantiate for the specified file.

Return value

If this function succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

Windows Internet Explorer 9. This function can also return a class identifier (CLSID) from structured storage files if sniffing is allowed for the security zone (URLACTION_ALLOW_STRUCTURED_STORAGE_SNIFFING is enabled) and sniffing is not disabled for the process by using FEATURE_RESTRICT_CDL_CLSIDSNIFF. Structured storage sniffing is enabled by default in the Local intranet and Trusted sites zones.

Requirements