PROPVARIANT

Windows Mobile 6.5
A version of this page is also available for
4/8/2010

This structure is used to define the type tag and the value of a property in a property set. There are five members. The first member, the value-type tag, and the last member, the value of the property, are significant. The middle three members are reserved for future use.

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The bool member in previous definitions of this structure has been renamed to boolVal, because some compilers now recognize bool as a keyword.
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The PROPVARIANT structure, defined below, includes types that can be serialized in the version 1 property set serialization format. The version 1 format supports all types allowed in the version 0 format plus some additional types. The added types include "Version 1" in the comment field below. Use these types only if a version 1 property set is intended.


typedef struct PROPVARIANT {
  VARTYPE vt;
  WORD    wReserved1;
  WORD    wReserved2;
  WORD    wReserved3;
  union {
    CHAR              cVal;
    UCHAR             bVal;
    SHORT             iVal; 
    USHORT            uiVal;
    LONG              lVal; 
    ULONG             ulVal;
    INT               intVal;
    UINT              uintVal;
    LARGE_INTEGER     hVal;
    ULARGE_INTEGER    uhVal;
    FLOAT             fltVal;
    DOUBLE            dblVal;
    VARIANT_BOOL      boolVal;
    SCODE             scode; 
    CY                cyVal;
    DATE              date;
    FILETIME          filetime;
    CLSID*            puuid;
    CLIPDATA*         pclipdata;
    BSTR              bstrVal;
    BSTRBLOB          bstrblobVal;
    BLOB              blob;
    LPSTR             pszVal;
    LPWSTR            pwszVal;
    IUnknown*         punkVal;
    IDispatch*        pdispVal;
    IStream*          pStream; 
    IStorage*         pStorage;
    LPVERSIONEDSTREAM pVersionedStream;
    LPSAFEARRAY       parray;
    CAC               cac;
    CAUB              caub;
    CAI               cai;
    CAUI              caui;
        CAL               cal;
    CAUL              caul;
    CAH               cah;
    CAUH              cauh;
    CAFLT             caflt;
    CADBL             cadbl; 
    CABOOL            cabool; 
    CASCODE           cascode;
    CACY              cacy;
    CADATE            cadate;
    CAFILETIME        cafiletime;
    CACLSID           cauuid;
    CACLIPDATA        caclipdata;
    CABSTR            cabstr;
    CABSTRBLOB        cabstrblob;
    CALPSTR           calpstr;
    CALPWSTR          calpwstr;
    CAPROPVARIANT     capropvar;
    CHAR*             pcVal;
    UCHAR*            pbVal;
    SHORT*            piVal;
    USHORT*           puiVal;
    LONG*             plVal;
    ULONG*            pulVal;
    INT*              pintVal;
    UINT*             puintVal;
    FLOAT*            pfltVal;
    DOUBLE*           pdblVal;
    VARIANT_BOOL*     pboolVal;
    DECIMAL*          pdecVal;
    SCODE*            pscode;
    CY*               pcyVal;
    DATE*             pdate;
    BSTR*             pbstrVal;
    IUnknown**        ppunkVal;
    IDispatch**       ppdispVal;
    LPSAFEARRAY*      pparray;
    PROPVARIANT*      pvarVal;
  };
} PROPVARIANT;

vt

Value type tag.

wReserved1

Reserved for future use.

wReserved2

Reserved for future use.

wReserved3

Reserved for future use.

cVal

VT_I1, Version 1

bVal

VT_UI1

iVal

VT_I2

uiVal

VT_UI2

lVal

VT_I4

ulVal

VT_UI4

intVal

VT_INT, Version 1

uintVal

VT_UINT, Version 1

hVal

VT_I8

uhVal

VT_UI8

fltVal

VT_R4

dblVal

VT_R8

boolVal

VT_BOOL

scode

VT_ERROR

cyVal

VT_CY

date

VT_DATE

filetime

VT_FILETIME

puuid

VT_CLSID

pclipdata

VT_CF

bstrVal

VT_BSTR

bstrblobVal

VT_BSTR_BLOB

blob

VT_BLOB, VT_BLOBOBJECT

pszVal

VT_LPSTR

pwszVal

VT_LPWSTR

punkVal

VT_UNKNOWN

pdispVal

VT_DISPATCH

pStream

VT_STREAM, VT_STREAMED_OBJECT

pStorage

VT_STORAGE, VT_STORED_OBJECT

pVersionedStream

VT_VERSIONED_STREAM

parray

VT_ARRAY | VT_*, Version 1

cac

VT_VECTOR | VT_I1, Version 1

caub

VT_VECTOR | VT_UI1

cai

VT_VECTOR | VT_I2

caui

VT_VECTOR | VT_UI2

cal

VT_VECTOR | VT_I4

caul

VT_VECTOR | VT_UI4

cah

VT_VECTOR | VT_I8

cauh

VT_VECTOR | VT_UI8

caflt

VT_VECTOR | VT_R4

cadbl

VT_VECTOR | VT_R8

cabool

VT_VECTOR | VT_BOOL

cascode

VT_VECTOR | VT_ERROR

cacy

VT_VECTOR | VT_CY

cadate

VT_VECTOR | VT_DATE

cafiletime

VT_VECTOR | VT_FILETIME

cauuid

VT_VECTOR | VT_CLSID

caclipdata

VT_VECTOR | VT_CF

cabstr

VT_VECTOR | VT_BSTR

cabstrblob

VT_VECTOR | VT_BSTR_BLOB

calpstr

VT_VECTOR | VT_LPSTR

calpwstr

VT_VECTOR | VT_LPWSTR

capropvar

VT_VECTOR | VT_VARIANT

pcVal

VT_BYREF | VT_I1, Version 1

pbVal

VT_BYREF | VT_UI1, Version 1

piVal

VT_BYREF | VT_I2, Version 1

puiVal

VT_BYREF | VT_UI2, Version 1

plVal

VT_BYREF | VT_I4, Version 1

pulVal

VT_BYREF | VT_UI4, Version 1

pintVal

VT_BYREF | VT_INT, Version 1

puintVal

VT_BYREF | VT_UINT, Version 1

pfltVal

VT_BYREF | VT_R4, Version 1

pdblVal

VT_BYREF | VT_R8, Version 1

pboolVal

VT_BYREF | VT_BOOL, Version 1

pdecVal

VT_BYREF | VT_DECIMAL, Version 1

pscode

VT_BYREF | VT_ERROR, Version 1

pcyVal

VT_BYREF | VT_CY, Version 1

pdate

VT_BYREF | VT_DATE, Version 1

pbstrVal

VT_BYREF | VT_BSTR, Version 1

ppunkVal

VT_BYREF | VT_UNKNOWN, Version 1

ppdispVal

VT_BYREF | VT_DISPATCH, Version 1

pparray

VT_BYREF | VT_ARRAY, Version 1

pvarVal

VT_BYREF | VT_VARIANT, Version 1

The PROPVARIANT structure can also hold a value of VT_DECIMAL:

    DECIMAL       decVal;        //VT_DECIMAL

However, the value of the DECIMAL structure requires special handling. The DECIMAL structure is the same size as an entire PROPVARIANT structure and does not fit into the union that holds all other types of values. Instead, the value of the DECIMAL structure occupies the entire PROPVARIANT structure, including the reserved fields and the vt member. However, the first member of the DECIMAL structure is not used and is equal in size to the vt member of the PROPVARIANT structure. Therefore, the PROPVARIANT structure declaration in the propidl.h header file defines the decVal member in such a way that it corresponds to the beginning of the PROPVARIANT structure. Therefore, to put the value of the DECIMAL structure into a PROPVARIANT structure, the value must be loaded into the decVal member and the vt member is set to VT_DECIMAL, just as for any other value.

The data type PROPVARIANT is related to the data type VARIANT, defined as part of Automation in OLE2. Several definitions are reused from Automation, as follows:

typedef struct  tagCY {
    unsigned long      Lo;
    long               Hi;
    } CY;
 
typedef struct  tagDEC {
    USHORT             wReserved;
    BYTE               scale;
    BYTE               sign;
    ULONG              Hi32;
    ULONGLONG          Lo64;
    } DECIMAL;
 
typedef struct  tagSAFEARRAYBOUND {
    ULONG              cElements;
    LONG               lLbound;
    } SAFEARRAYBOUND;
 
typedef struct  tagSAFEARRAY {
    USHORT             cDims;
    USHORT             fFeatures;
    ULONG              cbElements;
    ULONG              cLocks;
    PVOID              pvData;
    SAFEARRAYBOUND     rgsabound [ * ];
    } SAFEARRAY;
 
typedef CY             CURRENCY;
typedef short          VARIANT_BOOL;
typedef unsigned short VARTYPE;
typedef double         DATE;
typedef OLECHAR*       BSTR;

In addition, some types are unique to the PROPVARIANT structure:

typedef struct  tagCLIPDATA {
    // cbSize is the size of the buffer pointed to 
    // by pClipData, plus sizeof(ulClipFmt)
    ULONG              cbSize;
    long               ulClipFmt;
    BYTE*              pClipData;
    } CLIPDATA;

Among the unique PROPVARIANT types are several data types that define counted arrays of other data types. The data types of all counted arrays begin with the letters CA, for example CAUB, and have an OR operator vt value (the VarType of the element and an OR operator with VT_VECTOR). The counted array structure has the following form (where name is the specific name of the counted array).

#define TYPEDEF_CA(type, name) 
typedef struct tag ## name {\
        ULONG cElems;\
        type *pElems;\
        } name

Propvariant type Code PROPVARIANT Member Value Representation

VT_EMPTY

0

None

A property with a type indicator of VT_EMPTY has no data associated with it; that is, the size of the value is zero.

VT_NULL

1

None

This is like a pointer to NULL.

VT_I1

16

cVal

1-byte signed integer.

VT_UI1

17

bVal

1-byte unsigned integer.

VT_I2

2

iVal

Two bytes representing a 2-byte signed integer value.

VT_UI2

18

uiVal

2-byte unsigned integer.

VT_I4

3

lVal

4-byte signed integer value.

VT_UI4

19

ulVal

4-byte unsigned integer.

VT_INT

22

intVal

4-byte signed integer value (equivalent to VT_I4).

VT_UINT

23

uintVal

4-byte unsigned integer (equivalent to VT_UI4).

VT_I8

20

hVal

8-byte signed integer.

VT_UI8

21

uhVal

8-byte unsigned integer.

VT_R4

4

fltVal

32-bit IEEE floating point value.

VT_R8

5

dblVal

64-bit IEEE floating point value.

VT_BOOL

11

boolVal (bool in earlier designs)

Boolean value, a WORD containing 0 (FALSE) or -1 (TRUE).

VT_ERROR

10

scode

A DWORD containing a status code.

VT_CY

6

cyVal

8-byte two's complement integer (scaled by 10,000). This type is commonly used for currency amounts.

VT_DATE

7

date

A 64-bit floating point number representing the number of days (not seconds) since December 31, 1899. For example, January 1, 1900, is 2.0, January 2, 1900, is 3.0, and so on). This is stored in the same representation as VT_R8.

VT_FILETIME

64

filetime

64-bit FILETIME structure. It is recommended that all times be stored in Universal Coordinate Time (UTC).

VT_CLSID

72

puuid

Pointer to a class identifier (CLSID) (or other globally unique identifier (GUID)).

VT_CF

71

pclipdata

Pointer to a CLIPDATA structure, described above.

VT_BSTR

8

bstrVal

Pointer to a null-terminated Unicode string. The string is immediately preceded by a DWORD representing the byte count, but bstrVal points past this DWORD to the first character of the string. BSTRs must be allocated and freed using the Automation SysAllocString and SysFreeString calls.

VT_BSTR_BLOB

0xfff

bstrblobVal

For system use only.

VT_BLOB

65

blob

DWORD count of bytes, followed by that many bytes of data. The byte count does not include the four bytes for the length of the count itself; an empty blob member would have a count of zero, followed by zero bytes. This is similar to the value VT_BSTR, but does not guarantee a null byte at the end of the data.

VT_BLOBOBJECT

70

blob

A blob member containing a serialized object in the same representation that would appear in VT_STREAMED_OBJECT. That is, a DWORD byte count (where the byte count does not include the size of itself) which is in the format of a class identifier followed by initialization data for that class.

 

 

 

The only significant difference between VT_BLOB_OBJECT and VT_STREAMED_OBJECT is that the former does not have the system-level storage overhead that the latter would have, and is therefore more suitable for scenarios involving numbers of small objects.

VT_LPSTR

30

pszVal

Pointer to a null-terminated ANSI string in the system default code page.

VT_LPWSTR

31

pwszVal

Pointer to a null-terminated Unicode string in the user's default locale.

VT_UNKNOWN

13

punkVal

New

VT_DISPATCH

9

pdispVal

New

VT_STREAM

66

pStream

Pointer to an IStream interface, representing a stream which is a sibling to the "Contents" stream.

VT_STREAMED_OBJECT

68

pStream

As in VT_STREAM, but indicates that the stream contains a serialized object, which is a CLSID followed by initialization data for the class. The stream is a sibling to the "Contents" stream that contains the property set.

VT_STORAGE

67

pStorage

Pointer to an IStorage interface, representing a storage object that is a sibling to the "Contents" stream.

VT_STORED_OBJECT

69

pStorage

As in VT_STORAGE, but indicates that the designated IStorage contains a loadable object.

VT_VERSIONED_STREAM

73

pVersionedStream

A stream with a GUID version.

VT_DECIMAL

14

decVal

A DECIMAL structure.

VT_VECTOR

0x1000

ca*

If the type indicator is combined with VT_VECTOR by using an OR operator, the value is one of the counted array values. This creates a DWORD count of elements, followed by a pointer to the specified repetitions of the value.

 

 

 

For example, a type indicator of VT_LPSTR|VT_VECTOR has a DWORD element count, followed by a pointer to an array of LPSTR elements.

 

 

 

VT_VECTOR can be combined by an OR operator with the following types: VT_I1, VT_UI1, VT_I2, VT_UI2, VT_BOOL, VT_I4, VT_UI4, VT_R4, VT_R8, VT_ERROR, VT_I8, VT_UI8, VT_CY, VT_DATE, VT_FILETIME, VT_CLSID, VT_CF, VT_BSTR, VT_LPSTR, VT_LPWSTR, and VT_VARIANT. VT_VECTOR can also be combined by an OR operation with VT_BSTR_BLOB, however it is for system use only.

VT_ARRAY

0x2000

Parray

If the type indicator is combined with VT_ARRAY by an OR operator, the value is a pointer to a SAFEARRAY. VT_ARRAY can use the OR with the following data types: VT_I1, VT_UI1, VT_I2, VT_UI2, VT_I4, VT_UI4, VT_INT, VT_UINT, VT_R4, VT_R8, VT_BOOL, VT_DECIMAL, VT_ERROR, VT_CY, VT_DATE, VT_BSTR, VT_DISPATCH, VT_UNKNOWN, and VT_VARIANT. VT_ARRAY cannot use OR with VT_VECTOR.

VT_BYREF

0x4000

p*

If the type indicator is combined with VT_BYREF by an OR operator, the value is a reference. Reference types are interpreted as a reference to data, similar to the reference type in C++ (for example, "int&").

 

 

 

VT_BYREF can use OR with the following types: VT_I1, VT_UI1, VT_I2, VT_UI2, VT_I4, VT_UI4, VT_INT, VT_UINT, VT_R4, VT_R8, VT_BOOL, VT_DECIMAL, VT_ERROR, VT_CY, VT_DATE, VT_BSTR, VT_UNKNOWN, VT_DISPATCH, VT_ARRAY, and VT_VARIANT.

VT_VARIANT

12

capropvar

A DWORD type indicator followed by the corresponding value. VT_VARIANT can be used only with VT_VECTOR or VT_BYREF.

VT_TYPEMASK

0xFFF

 

Used as a mask for VT_VECTOR and other modifiers to extract the raw VT value.

Headeroaidl.h
Windows Embedded CEWindows CE 2.0 and later
Windows MobileWindows Mobile Version 5.0 and later
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