SetOleProperty(
Guid fmtid,
uint propId,
object propVal
)
{
CheckDisposed();
IPropertyStorage ps =
fmtid == FormatId.SummaryInformation ? _psSummInfo : _psDocSummInfo;
if (ps == null)
{
//
// The property set does not exist, so create it.
//
if (propVal != null)
{
_pss.Create(
ref fmtid,
ref fmtid,
SafeNativeCompoundFileConstants.PROPSETFLAG_ANSI,
(uint)_grfMode,
out ps
);
if (fmtid == FormatId.SummaryInformation)
{
_psSummInfo = ps;
}
else
{
_psDocSummInfo = ps;
}
}
else
{
//
// But if we were going to delete the property anyway, there's
// nothing to do.
//
return;
}
}
PROPSPEC[] propSpecs = new PROPSPEC[1];
PROPVARIANT[] vals = new PROPVARIANT[1];
propSpecs[0].propType = (uint)PropSpecType.Id;
propSpecs[0].union.propId = propId;
if (propVal == null)
{
//
// New value is null => remove the property. Unlike in the case of ReadMultiple,
// we can just let this one throw an exception on failure. There are no non-zero
// success codes to worry about.
//
ps.DeleteMultiple(1, propSpecs);
return;
}
//
// New value is non-null => set a new value for the property.
//
IntPtr pszVal = IntPtr.Zero;
try
{
if (propVal is string)
{
//
// 1) We store string properties internally as UTF-16.
// During save, convert the string (UTF-16) to CP_ACP and back
// 2) If property value changed during that process, store it in CF OLE Storage as UTF-8
// 3) Otherwise store it as CP_ACP
//
string inputString = propVal as string;
pszVal = Marshal.StringToCoTaskMemAnsi(inputString);
string convertedString = Marshal.PtrToStringAnsi(pszVal);
if (String.CompareOrdinal(inputString, convertedString) != 0)
{
// The string is not an ASCII string. Use UTF-8 to encode it!
byte[] byteArray = UTF8Encoding.UTF8.GetBytes(inputString);
int nLen = byteArray.Length;
//
// Before memory allocation for holding UTF-8 codes, we need to first free the memory
// allocated by Marshal.StringToCoTaskMemAnsi().
// Note that if there is any exception in this try scope, the memory will still be released
// by the finally of this try scope.
//
if (pszVal != IntPtr.Zero)
{
Marshal.FreeCoTaskMem(pszVal);
pszVal = IntPtr.Zero;
}
pszVal = Marshal.AllocCoTaskMem(checked (nLen + 1)); //The extra one byte is for the string terminator null.
Marshal.Copy(byteArray, 0, pszVal, nLen);
Marshal.WriteByte(pszVal, nLen, 0); //Put the string terminator null at the end of the array.
}
vals[0].vt = VARTYPE.VT_LPSTR;
vals[0].union.pszVal = pszVal;
}
else if (propVal is DateTime)
{
// set FileTime as an Int64 to avoid pointer operations
vals[0].vt = VARTYPE.VT_FILETIME;
vals[0].union.hVal = ((DateTime)propVal).ToFileTime();
}
else
{
throw new ArgumentException(
SR.Get(SRID.InvalidDocumentPropertyType, propVal.GetType().ToString()),
"propVal");
}
//
// Again, we can just let it throw on failure; no non-zero success codes. It won't throw
// if the property doesn't exist.
//
ps.WriteMultiple(1, propSpecs, vals, 0);
}
finally
{
if (pszVal != IntPtr.Zero)
{
Marshal.FreeCoTaskMem(pszVal);
}
}
}