public override Object ChangeType(Object value, Type type, CultureInfo cultureInfo)
{
Variant myValue = new Variant(value);
if (cultureInfo == null)
cultureInfo = CultureInfo.CurrentCulture;
#if DISPLAY_DEBUG_INFO
Console.Write("In OleAutBinder::ChangeType converting variant of type: ");
Console.Write(myValue.VariantType);
Console.Write(" to type: ");
Console.WriteLine(type.Name);
#endif
if (type.IsByRef)
{
#if DISPLAY_DEBUG_INFO
Console.WriteLine("Striping byref from the type to convert to.");
#endif
type = type.GetElementType();
}
// If we are trying to convert from an object to another type then we don't
// need the OLEAUT change type, we can just use the normal COM+ mechanisms.
if (!type.IsPrimitive && type.IsInstanceOfType(value))
{
#if DISPLAY_DEBUG_INFO
Console.WriteLine("Source variant can be assigned to destination type");
#endif
return value;
}
Type srcType = value.GetType();
// Handle converting primitives to enums.
if (type.IsEnum && srcType.IsPrimitive)
{
#if DISPLAY_DEBUG_INFO
Console.WriteLine("Converting primitive to enum");
#endif
return Enum.Parse(type, value.ToString());
}
// Special case the convertion from DBNull.
if (srcType == typeof(DBNull))
{
// The requested type is a DBNull so no convertion is required.
if (type == typeof(DBNull))
return value;
// Visual J++ supported converting from DBNull to null so customers
// have requested (via a CDCR) that DBNull be convertible to null.
// We don't however allow this when converting to a value class, since null
// doesn't make sense for these, or to object since this would change existing
// semantics.
if ((type.IsClass && type != typeof(Object)) || type.IsInterface)
return null;
}
return base.ChangeType(value, type, cultureInfo);
}
