internal static Type GetTypeForVarEnum(VarEnum vt)
{
Type type;
switch (vt)
{
// VarEnums which can be used in VARIANTs, but which cannot occur in a TYPEDESC
case VarEnum.VT_EMPTY:
case VarEnum.VT_NULL:
case VarEnum.VT_RECORD:
type = typeof(void);
break;
// VarEnums which are not used in VARIANTs, but which can occur in a TYPEDESC
case VarEnum.VT_VOID:
type = typeof(void);
break;
case VarEnum.VT_HRESULT:
type = typeof(int);
break;
case ((VarEnum)37): // VT_INT_PTR:
type = typeof(IntPtr);
break;
case ((VarEnum)38): // VT_UINT_PTR:
type = typeof(UIntPtr);
break;
case VarEnum.VT_SAFEARRAY:
case VarEnum.VT_CARRAY:
type = typeof(Array);
break;
case VarEnum.VT_LPSTR:
case VarEnum.VT_LPWSTR:
type = typeof(string);
break;
case VarEnum.VT_PTR:
case VarEnum.VT_USERDEFINED:
type = typeof(object);
break;
// For VarEnums that can be used in VARIANTs and well as TYPEDESCs, just use VarEnumSelector
default:
type = VarEnumSelector.GetManagedMarshalType(vt);
break;
}
return(type);
}
/// <summary>
/// Creates a representation for the parameter of a COM method
/// </summary>
internal ComParamDesc(ref ELEMDESC elemDesc, string name)
{
// Ensure _defaultValue is set to DBNull.Value regardless of whether or not the
// default value is extracted from the parameter description. Failure to do so
// yields a runtime exception in the ToString() function.
DefaultValue = DBNull.Value;
if (!string.IsNullOrEmpty(name))
{
// This is a parameter, not a return value
IsOut = (elemDesc.desc.paramdesc.wParamFlags & PARAMFLAG.PARAMFLAG_FOUT) != 0;
IsOptional = (elemDesc.desc.paramdesc.wParamFlags & PARAMFLAG.PARAMFLAG_FOPT) != 0;
// TODO: The PARAMDESCEX struct has a memory issue that needs to be resolved. For now, we ignore it.
//_defaultValue = PARAMDESCEX.GetDefaultValue(ref elemDesc.desc.paramdesc);
}
_name = name;
_vt = (VarEnum)elemDesc.tdesc.vt;
TYPEDESC typeDesc = elemDesc.tdesc;
while (true)
{
if (_vt == VarEnum.VT_PTR)
{
ByReference = true;
}
else if (_vt == VarEnum.VT_ARRAY)
{
IsArray = true;
}
else
{
break;
}
TYPEDESC childTypeDesc = (TYPEDESC)Marshal.PtrToStructure(typeDesc.lpValue, typeof(TYPEDESC));
_vt = (VarEnum)childTypeDesc.vt;
typeDesc = childTypeDesc;
}
VarEnum vtWithoutByref = _vt;
if ((_vt & VarEnum.VT_BYREF) != 0)
{
vtWithoutByref = (_vt & ~VarEnum.VT_BYREF);
ByReference = true;
}
ParameterType = VarEnumSelector.GetTypeForVarEnum(vtWithoutByref);
}
internal DynamicMetaObject Invoke()
{
_keywordArgNames = _callInfo.ArgumentNames.ToArray();
_totalExplicitArgs = _args.Length;
Type[] marshalArgTypes = new Type[_args.Length];
// We already tested the instance, so no need to test it again
for (int i = 0; i < _args.Length; i++)
{
DynamicMetaObject curMo = _args[i];
marshalArgTypes[i] = MarshalType(curMo, _isByRef[i]);
}
_varEnumSelector = new VarEnumSelector(marshalArgTypes);
return(new DynamicMetaObject(
CreateScope(MakeIDispatchInvokeTarget()),
BindingRestrictions.Combine(_args).Merge(_restrictions)
));
}
