internal ComParamInfo(String name, String typeName, PARAMFLAG paramFlags)
{
_name = name;
_type = typeName;
_paramFlags = paramFlags;
}
public ParamDesc(Object parent, IntPtr lpVarValue, PARAMFLAG flag)
{
m_lpVarValue = lpVarValue;
m_paramflag = flag;
m_parent = parent;
}
private Object m_parent; // hold on to parent to avoid GC hole
#endregion Fields
#region Constructors
public ParamDesc(Object parent, IntPtr lpVarValue, PARAMFLAG flag)
{
m_lpVarValue = lpVarValue;
m_paramflag = flag;
m_parent = parent;
}
internal ComParamInfo(String name, String typeName, PARAMFLAG paramFlags)
{
_name = name;
_type = typeName;
_paramFlags = paramFlags;
}
/// <summary>
/// Gets parameter information for the given member.
/// </summary>
/// <remarks>
/// Uses the COM ITypeInfo interface to get the information. Does not throw. If it returns false then the out params
/// will not hold useful information.
/// </remarks>
/// <param name="obj"></param>
/// <param name="memberName"></param>
/// <param name="callType"></param>
/// <param name="isBeingCalledWithZeroArgs"></param>
/// <param name="paramTypes"></param>
/// <param name="paramFlags"></param>
/// <param name="endsWithParamArray"></param>
/// <returns>true if the name refers to a valid member or if no type information is available</returns>
///
internal static bool GetMemberInfo(object obj, ref string memberName, int callType, bool isBeingCalledWithZeroArgs,
out Type[] paramTypes, out PARAMFLAG[] paramFlags, out bool endsWithParamArray)
{
// There are some early returns in this method, so we initialize the out params right away. To the caller, if these values
// come back null it means that the information could not be determined.
paramTypes = null;
paramFlags = null;
endsWithParamArray = false;
int defaultLCID = GetUserDefaultLCID();
try {
// Throws in this outer try cause true to be returned. They mean "type info could not be obtained, so the member is not
// known to be invalid."
UCOMIDispatch iDisp = GetIDispatch(obj);
int memberDispId = GetMemberDispID(obj, iDisp, ref memberName);
if (memberDispId == -1)
{
// Name not found by GetIDsOfNames.
return(false);
}
// If no args are being passed, then we can skip all the machinations below about type info.
if (isBeingCalledWithZeroArgs)
{
return(true);
}
UCOMITypeInfo iTypeInfo = GetITypeInfo(obj, iDisp);
IntPtr pFuncDesc;
// Check to see if the func index for this member name is already cached from a previous call.
FuncIndexHolder fih = (FuncIndexHolder)Marshal.GetComObjectData(obj, "NETLinkFuncIndex" + memberName);
if (fih == null)
{
// This will be populated below.
fih = new FuncIndexHolder();
Marshal.SetComObjectData(obj, "NETLinkFuncIndex" + memberName, fih);
}
int funcIndex = -1;
if (callType == Install.CALLTYPE_FIELD_OR_SIMPLE_PROP_GET)
{
if (fih.funcIndexForCALLTYPE_FIELD_OR_SIMPLE_PROP_GET != -1)
{
funcIndex = fih.funcIndexForCALLTYPE_FIELD_OR_SIMPLE_PROP_GET;
}
}
else if (callType == Install.CALLTYPE_FIELD_OR_SIMPLE_PROP_SET || callType == Install.CALLTYPE_PARAM_PROP_SET)
{
if (fih.funcIndexForCALLTYPE_FIELD_OR_ANY_PROP_SET != -1)
{
funcIndex = fih.funcIndexForCALLTYPE_FIELD_OR_ANY_PROP_SET;
}
}
else if (callType == Install.CALLTYPE_METHOD || callType == Install.CALLTYPE_PARAM_PROP_GET)
{
// COM objects are treated by M code as if they all have indexers, so calls like obj[1] will
// come in as CALLTYPE_PARAM_PROP_GET with a property name of Item. We can just treat these like
// method calls.
if (fih.funcIndexForCALLTYPE_METHOD != -1)
{
funcIndex = fih.funcIndexForCALLTYPE_METHOD;
}
}
// Did not have the func index for this call type cached.
if (funcIndex == -1)
{
IntPtr pTypeAttr;
iTypeInfo.GetTypeAttr(out pTypeAttr);
TYPEATTR typeAttr = (TYPEATTR)Marshal.PtrToStructure(pTypeAttr, typeof(TYPEATTR));
int numFuncs = typeAttr.cFuncs;
iTypeInfo.ReleaseTypeAttr(pTypeAttr);
bool foundDispId = false;
for (int thisIndex = 0; thisIndex < numFuncs; thisIndex++)
{
// Be aware that GetFuncDesc() can (I think) throw a cryptic "Element not found" exception,
// such as for a hidden property like (Excel) _Application.ActiveDialog.
iTypeInfo.GetFuncDesc(thisIndex, out pFuncDesc);
FUNCDESC funcDesc = (FUNCDESC)Marshal.PtrToStructure(pFuncDesc, typeof(FUNCDESC));
int thisMemberId = funcDesc.memid;
INVOKEKIND invokeKind = funcDesc.invkind;
iTypeInfo.ReleaseFuncDesc(pFuncDesc);
if (thisMemberId == memberDispId)
{
foundDispId = true;
// Verify that it is a member of the correct call type.
if (callType == Install.CALLTYPE_FIELD_OR_SIMPLE_PROP_GET && invokeKind == INVOKEKIND.INVOKE_PROPERTYGET)
{
fih.funcIndexForCALLTYPE_FIELD_OR_SIMPLE_PROP_GET = thisIndex;
funcIndex = thisIndex;
break;
}
else if ((callType == Install.CALLTYPE_FIELD_OR_SIMPLE_PROP_SET || callType == Install.CALLTYPE_PARAM_PROP_SET) &&
(invokeKind == INVOKEKIND.INVOKE_PROPERTYPUT || invokeKind == INVOKEKIND.INVOKE_PROPERTYPUTREF))
{
fih.funcIndexForCALLTYPE_FIELD_OR_ANY_PROP_SET = thisIndex;
funcIndex = thisIndex;
break;
}
else if ((callType == Install.CALLTYPE_METHOD && (invokeKind == INVOKEKIND.INVOKE_FUNC || invokeKind == INVOKEKIND.INVOKE_PROPERTYGET)) ||
(callType == Install.CALLTYPE_PARAM_PROP_GET && invokeKind == INVOKEKIND.INVOKE_PROPERTYGET))
{
// Parameterized prop gets, not sets, look like CALLTYPE_METHOD. Also, as discussed in an earlier comment,
// indexer notation calls (obj[1]) are supported for all COM objects and come in as CALLTYPE_PARAM_PROP_GET.
fih.funcIndexForCALLTYPE_METHOD = thisIndex;
funcIndex = thisIndex;
break;
}
}
}
if (funcIndex == -1)
{
// We didn't find the member in our search. This can happen in two ways. First, the member might
// exist but not be the right call type. For this case we want to return false. Second, we didn't
// even find the dispid. This can happen in unusual cases I don't understan An example of this
// is the IWebBrowser2 interface obtained by CreateCOMObject["InternetExplorer.Application"].
// For this case we want to return true, as if there was no type info at all available, so the
// call can still proceed.
return(!foundDispId);
}
}
// If we get to here, we have a valid funcIndex and memberDispId, and the member is of the correct variety
// that corresponds to how it was called (e.g., it's a method and it was called as such). All that
// remains is to get the parameter types.
iTypeInfo.GetFuncDesc(funcIndex, out pFuncDesc);
try {
FUNCDESC funcDesc = (FUNCDESC)Marshal.PtrToStructure(pFuncDesc, typeof(FUNCDESC));
Debug.Assert(funcDesc.memid == memberDispId);
int paramCount = funcDesc.cParams;
// Functions that end with a VB-style ParamArray (a variable-length argument sequence) have -1 for the
// cParamsOpt member. It is convenient to treat them specially, hence the 'endsWithParamArray' variable
// (which is an out param for this method). The special treatment involves leaving the ParamArray arg off
// the list of paramFlags and paramTypes. We just pretend there is one less arg to the function but
// record that it ends with a ParamArray. We always know the type of this arg anyway: ByRef Variant[].
// To the caller, though, the individual args are sent as a sequence, not packed into an array.
endsWithParamArray = funcDesc.cParamsOpt == -1;
if (endsWithParamArray)
{
paramCount--;
}
paramTypes = new Type[paramCount];
paramFlags = new PARAMFLAG[paramCount];
IntPtr pElemDescArray = funcDesc.lprgelemdescParam;
for (int paramIndex = 0; paramIndex < paramCount; paramIndex++)
{
ELEMDESC elemDesc = (ELEMDESC)Marshal.PtrToStructure((IntPtr)(pElemDescArray.ToInt64() +
paramIndex * Marshal.SizeOf(typeof(ELEMDESC))), typeof(ELEMDESC));
TYPEDESC typeDesc = elemDesc.tdesc;
paramFlags[paramIndex] = elemDesc.desc.paramdesc.wParamFlags;
// I think I should never see a retval param here. They have been automatically converted to return types.
Debug.Assert((paramFlags[paramIndex] & PARAMFLAG.PARAMFLAG_FRETVAL) == 0);
VarEnum variantType = (VarEnum)typeDesc.vt;
bool isArray = variantType == VarEnum.VT_SAFEARRAY;
bool isPtr = variantType == VarEnum.VT_PTR;
bool isOut = (paramFlags[paramIndex] & PARAMFLAG.PARAMFLAG_FOUT) != 0;
// VB array params will have isPtr and !isArray, because they are always ByRef (thus ptrs).
// In general (always?), out params will be VT_PTR.
if (isArray || isPtr)
{
IntPtr pElementTypeDesc = typeDesc.lpValue;
TYPEDESC elementTypeDesc = (TYPEDESC)Marshal.PtrToStructure(pElementTypeDesc, typeof(TYPEDESC));
variantType = (VarEnum)elementTypeDesc.vt;
// If the arg was a ptr to an array (e.g., as in VB objects), do it again to get the element type.
if (variantType == VarEnum.VT_SAFEARRAY)
{
isArray = true;
pElementTypeDesc = elementTypeDesc.lpValue;
elementTypeDesc = (TYPEDESC)Marshal.PtrToStructure(pElementTypeDesc, typeof(TYPEDESC));
variantType = (VarEnum)elementTypeDesc.vt;
}
}
paramTypes[paramIndex] = managedTypeForVariantType(variantType, isArray, isPtr, isOut);
}
} finally {
iTypeInfo.ReleaseFuncDesc(pFuncDesc);
}
return(true);
} catch (Exception) {
return(true);
}
}
