internal static int GetProperty(this IPropertyStorage propertyStorage, uint propid, out PROPVARIANT propvar)
{
HRESULT hr = (int)HRESULT.E_FAIL;
propvar = default(PROPVARIANT);
PROPSPEC[] propspec = new PROPSPEC[1];
PROPVARIANT[] propvars = { propvar };
propspec[0].ulKind = (uint)PRSPEC.PROPID;
propspec[0].u.propId = propid;
if (NativeMethods.Succeeded(hr = propertyStorage.ReadMultiple(1, propspec, propvars)))
{
propvar = propvars[0];
}
return(hr);
}
GetOleProperty(
Guid fmtid,
uint propId
)
{
CheckDisposed();
// fmtid is always either DocSum or Sum.
IPropertyStorage ps =
fmtid == FormatId.SummaryInformation ? _psSummInfo : _psDocSummInfo;
if (ps == null)
{
// This file doesn't even contain the property storage that this
// property belongs to, so it certainly doesn't contain the property.
return(null);
}
object obj = null;
PROPSPEC[] propSpecs = new PROPSPEC[1];
PROPVARIANT[] vals = new PROPVARIANT[1];
propSpecs[0].propType = (uint)PropSpecType.Id;
propSpecs[0].union.propId = propId;
VARTYPE vtExpected = GetVtFromPropId(fmtid, propId);
int hresult = ps.ReadMultiple(1, propSpecs, vals);
if (hresult == SafeNativeCompoundFileConstants.S_OK)
{
try
{
if (vals[0].vt != vtExpected)
{
throw new FileFormatException(
SR.Get(
SRID.WrongDocumentPropertyVariantType,
propId,
fmtid.ToString(),
vals[0].vt,
vtExpected
)
);
}
switch (vals[0].vt)
{
case VARTYPE.VT_LPSTR:
//
// We store string properties as CP_ACP or UTF-8.
// But no matter which format the string was encoded, we always use the UTF-8
// encoder/decoder to decode the byte array, because the UTF-8 code of an ASCII
// string is the same as the ASCII string.
//
IntPtr pszVal = vals[0].union.pszVal;
//
// Because both the ASCII string and UTF-8 encoded string (byte array) are
// stored in a memory block (pszVal) terminated by null, we can use
// Marshal.PtrToStringAnsi(pszVal) to convert the memory block pointed by
// pszVal to a string. Then from the string.Length, we can get the number of
// bytes in the memory block. Otherwise, we cannot easily tell how many bytes
// are stored in pszVal without an extra parameter.
//
string ansiString = Marshal.PtrToStringAnsi(pszVal);
int nLen = ansiString.Length;
byte[] byteArray = new byte[nLen];
Marshal.Copy(pszVal, byteArray, 0, nLen);
obj = UTF8Encoding.UTF8.GetString(byteArray);
break;
case VARTYPE.VT_FILETIME:
//
// DateTime doesn't have a conversion from FILETIME. It has a
// misleadingly named "FromFileTime" method that actually wants
// a long. So...
//
obj = new Nullable <DateTime>(DateTime.FromFileTime(vals[0].union.hVal));
break;
default:
throw new FileFormatException(
SR.Get(SRID.InvalidDocumentPropertyVariantType, vals[0].vt));
}
}
finally
{
#pragma warning suppress 6031 // suppressing a "by design" ignored return value
SafeNativeCompoundFileMethods.SafePropVariantClear(ref vals[0]);
}
}
else if (hresult == SafeNativeCompoundFileConstants.S_FALSE)
{
// Do nothing -- return the null object reference.
}
else
{
SecurityHelper.ThrowExceptionForHR(hresult);
}
return(obj);
}
