which coclass in C# COM server is initialized? - COM Discussion Boards

Re: Accessing COM component from JScript

User 21559723-Jul-07 21:01

User 215597

23-Jul-07 21:01

Does the following sample work in your browser (It works fine on my IE6 browser)

<html><br />
<head><br />
<script type="text/javascript"><br />
var xmlhttp;<br />
<br />
function testXMLHttp()<br />
{<br />
xmlhttp=null<br />
// code for Mozilla, etc.<br />
if (window.XMLHttpRequest)<br />
  {<br />
  xmlhttp=new XMLHttpRequest()<br />
  }<br />
// code for IE<br />
else if (window.ActiveXObject)<br />
  {<br />
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP")<br />
  }<br />
if (xmlhttp!=null)<br />
  {<br />
  alert("Your browser does support XMLHTTP.")<br />
  }<br />
else<br />
  {<br />
  alert("Your browser does not support XMLHTTP.")<br />
  }<br />
}<br />
</script><br />
</head><br />
<body onload="testXMLHttp()"><br />
<br />
</body><br />
</html>

Sohail

modified 21-Apr-21 21:01pm.

Re: Accessing COM component from JScript

PriyaJ.220623-Jul-07 21:08

PriyaJ.2206

23-Jul-07 21:08

Thanks Sohail,
Actually when i was trying to fix it up, I came to know that the problem is only when accessing my component. I tried creating another simple component and accessed it by creating object through ActiveXObject, it works fine.

I'm creating a CAxWindow object and embedding the html content into a toolbar using CAxWindow's create control method. Now I doubt whether creating a CAxWindow causes the actual problem.

Priya

Re: Accessing COM component from JScript

User 21559723-Jul-07 21:16

User 215597

23-Jul-07 21:16

PriyaJ.2206 wrote:
Actually when i was trying to fix it up, I came to know that the problem is only when accessing my component. I tried creating another simple component and accessed it by creating object through ActiveXObject, it works fine.

Good.

Sohail

modified 21-Apr-21 21:01pm.

Pass user defined type array

scheewie20-Jul-07 3:23

scheewie

20-Jul-07 3:23

Hi,

I'm trying to get a c# server component to pass a user defined type array to a VB6 client component through COM+. Is this possible with early binding?

I have created a c# component that works fine in COM (it passes bool, int etc). But when I try to pass a user defined type array, the array received in VB6 is empty (0 items), even tough I force the c# component to return at least one item in the array.

Heres my code:
C# function:
public MyType[] MyTypes()
{
MyType[] mt = {new MyType()};

return mt;
}

VB6 call:
Dim tool as MySpace.Tools
Dim retVal() as MySpace.MyType
Set tool = new MySpace.Tools

retVal = tool.MyTypes

Output UBound retVal gives 0 items.

Can't I pass arrays like this between C# and VB6 in COM+?
What is the solution to my problem?

Thanks in advance!

BR
Øivind

Re: Pass user defined type array

sthotakura23-Jul-07 8:02

sthotakura

23-Jul-07 8:02

try return them as Object s

Cheers,
Suresh

How to include header file "Gdiplus.h" in IDL file

Bidesh Mukherjee18-Jul-07 21:26

Bidesh Mukherjee

18-Jul-07 21:26

Hi all,

I have static lib which i want to convert into COM DLL. so have write an IDL file.
In this IDL file i have to define a structure which contains another structure COLOR which is defined in "Gdiplus.h".

My question is whether i can add this header file "Gdiplus.h" in the IDL file?
If yes then how. note that after including the "Gdiplus.h" i have mention its namespace also which is Gdiplus.

I have done it by including #import "Gdiplus.h" but error such as this is generated

C:\Program Files\Microsoft Platform SDK for Windows Server 2003 R2\Include\Gdiplus.h(25) : error MIDL2025 : syntax error : expecting an interface name or DispatchInterfaceName or CoclassName or ModuleName or LibraryName or a type specification near "namespace"

The IDL file for your reference...

//----------------------------------------------------------------------------
// File: Control.idl
//
// Desc: Interface definition for the IControl
//
//----------------------------------------------------------------------------

import "oaidl.idl";
import "ocidl.idl";
import "Gdiplus.h";
using namespace Gdiplus;

cpp_quote("// Structure containing the various color details of the meter display")
typedef struct _ColorInfo
{
Color NeedlePointerColor;
Color NeedleJointColor;
//Color TextColor;
COLORREF TextColor;
Color LargeGridColor;
Color SmallGridColor;
Color BackGroundColor;

// Constructor
_ColorInfo()
{
NeedlePointerColor = Color(255,163, 163, 163);
NeedleJointColor = Color(255,255, 255, 0);
//TextColor = Color(255,255, 255, 255);
TextColor = RGB(255, 255, 255);
LargeGridColor = Color(255,255, 255, 255);
SmallGridColor = Color(255,255, 255, 255);
BackGroundColor = Color(255, 0, 0, 0);
}

// Copy Constructor
_ColorInfo(const _ColorInfo &ColorInfo)
{
NeedlePointerColor = ColorInfo.NeedlePointerColor;
NeedleJointColor = ColorInfo.NeedleJointColor;
TextColor = ColorInfo.TextColor;
LargeGridColor = ColorInfo.LargeGridColor;
SmallGridColor = ColorInfo.SmallGridColor;
BackGroundColor = ColorInfo.BackGroundColor;
}

// Assignment operator overloading
_ColorInfo & operator = (const _ColorInfo &ColorInfo)
{
NeedlePointerColor = ColorInfo.NeedlePointerColor;
NeedleJointColor = ColorInfo.NeedleJointColor;
TextColor = ColorInfo.TextColor;
LargeGridColor = ColorInfo.LargeGridColor;
SmallGridColor = ColorInfo.SmallGridColor;
BackGroundColor = ColorInfo.BackGroundColor;
return *this;
}
} COLORINFO;

//-------------------------------------------------------------------------
// IControl Interface Confused | :confused:

// Desc: Exposes initialization method for the Control dll
//-------------------------------------------------------------------------
[
object,
uuid(5BC8F091-28C0-42aa-AD10-AA78E612D6AA),
version(1.0),
helpstring("IControl Interface"),
pointer_default(unique)
]

interface IControl : IUnknown
{
cpp_quote("// Displays the control")
[id(2), helpstring("method ShowControl")]
HRESULT ShowControl( );
}

//{5E3CE754-FCC9-454e-B4BE-D1DD470BAF1E}
//{ 0x5e3ce754, 0xfcc9, 0x454e, { 0xb4, 0xbe, 0xd1, 0xdd, 0x47, 0xb, 0xaf, 0x1e } };
[
uuid(5E3CE754-FCC9-454e-B4BE-D1DD470BAF1E),
helpstring("Meter Class")
]
coclass Meter
{
[default] interface IControl;
};

Can anyone help me.

Thanks,
Bidesh

Re: How to include header file "Gdiplus.h" in IDL file

User 21559719-Jul-07 20:44

User 215597

19-Jul-07 20:44

MIDL keyword Include[^]may help.

Sohail

modified 21-Apr-21 21:01pm.

which coclass in C# COM server is initialized?

George_George17-Jul-07 21:26

George_George

17-Jul-07 21:26

Hello everyone,

I am writing C# COM server (managed code). Since there is no QueryInterface, DllGetClassObject like in C++ native code, I am wondering how to know which coclass is initialized and which method is invoking by client?

I have such question is because I only develop COM server, and there are some dll level error (dll no longer available, something like this), so I think COM client may use some coclass/methods which my COM server does not support. But I do not have COM client source codes, so I am wondering how to get the information (which coclass/method client is using).

thanks in advance,
George

returning array of BSTRs from the COM component

Raj Prathap17-Jul-07 2:25

Raj Prathap

17-Jul-07 2:25

Hi,
I have a method which has to return the array of BSTRs. I'm giving the method here, please let me know if I'm doing anything wrong.

<br />
HRESULT Login([in] BSTR UserName, [in] BSTR Password, int maxUsrCnt , [out]int *UsrCnt, [out, length_is(,*UsrCnt), size_is(,maxUsrCnt)] BSTR *LoggedUsers);<br />

the size of the array to be returned is not known at the time of calling.
When I use this method, the first string is coming properly, but other strings are not coming.

Please suggest an answer.

Regards,
Raja Pratap

Re: returning array of BSTRs from the COM component

Mike Dimmick17-Jul-07 2:52

Mike Dimmick

17-Jul-07 2:52

I'd avoid trying to mix BSTRs and custom marshalling. Instead, I'd go with a SAFEARRAY of BSTR. To return such an array to a VB client, I'm using:

HRESULT ExtendedHardwareType([out, retval] SAFEARRAY(BSTR)* psArray);

Stability. What an interesting concept. -- Chris Maunder

Re: returning array of BSTRs from the COM component

Raj Prathap18-Jul-07 20:20

Raj Prathap

18-Jul-07 20:20

Thanks a ton Mike, working and its very easy to code.

Unable to Start Exchange service

Ashish Vasudev16-Jul-07 23:09

Ashish Vasudev

16-Jul-07 23:09

I am using Microsoft Exchange 2003 to replicate mails and folders. but i am not able to replicate folders in exchange through my code. while looking at at the services, i found that the service named Microsoft Exchange Event is not started except the other services. On starting the service manually i get the message "Services Stop automatically if they do not have any work to do".

Ashish Vasudev

Apartment (STA) mode before OLE calls

MadmanWoo16-Jul-07 21:03

MadmanWoo

16-Jul-07 21:03

Hi all,

I have a VB.NET program that has a OLE COM object imbedded in the form, the OLE object can send information back to my program by using callback which is set up as a class.

In the Callback class I have a sub set up to handle every time the OLE window changes which works fine, now the fun begins. I set up another sub which takes a string from the sub receiving the callback message, it then uses this string to select a control on the main form like so

Dim pnl as Panel = Mainform.pnlLegend.Controls.Item({String})

When ever it gets to this line it throws the error "Current thread must be set to single thread apartment (STA) mode before OLE calls can be made".

I have searched all over the net looking but the only help I can find on this is stuff to do with remote clipboards. Hopefully someone on here maybe able to help me with this.

Thanks
Nathan

Re: Apartment (STA) mode before OLE calls

User 21559716-Jul-07 22:58

User 215597

16-Jul-07 22:58

Mike Stall blog[^]

MSDN link[^]

I hope this helps. BTW I picked these from Search results[^]

S o h a i l K a d i w a l a

To Err Is Human; to Debug, Divine

modified 21-Apr-21 21:01pm.

Re: Apartment (STA) mode before OLE calls

MadmanWoo18-Jul-07 12:41

MadmanWoo

18-Jul-07 12:41

Thanks,

I had a look at the link you said, it helped a bit but I still can't get around this problem.

It seems like the form runs in STA mode but the class that is set to handle callbacks is set to MTA mode. I have tried to set the Apartment mode to STA in the callback class but it just throws the error: "Can not set to STA" or something along those lines.

As you can see I'm not 100% sure where I have to set the class to run in STA mode. I have tried to put the <stathread> above Main in both in the form and in the Class but no luck Sigh | :sigh:

.

Can anyone help me on this one?

P.S I'm using VB.NET if I havn't said before

Re: Apartment (STA) mode before OLE calls

User 21559719-Jul-07 19:44

User 215597

19-Jul-07 19:44

MadmanWoo wrote:
In the Callback class I have a sub set up to handle every time the OLE window changes which works fine, now the fun begins. I set up another sub which takes a string from the sub receiving the callback message, it then uses this string to select a control on the main form like so

Dim pnl as Panel = Mainform.pnlLegend.Controls.Item({String})

When ever it gets to this line it throws the error "Current thread must be set to single thread apartment (STA) mode before OLE calls can be made".

I believe the problem happens because your callback and the control, whose property you are setting, are in different appartments. Will it help if you make the call from your event handling sub to another sub as non blocking instead of a blocking call - post the string to a queue or post the reuquest to your UI thread etc

What appartment mode does your main thread run in?

Sohail

modified 21-Apr-21 21:01pm.

Regarding COM's Server type(DLL or EXE)

Karismatic13-Jul-07 21:39

Karismatic

13-Jul-07 21:39

I have created a COM based application using DLL server.But i havn't used server as type of EXE.I don't know the exact difference when i will have to use DLL Server or EXE Server with COM base application.
Plase reply me as soon as possible.

Thanks & Regards
Pankaj

Regards,
Pankaj Sachdeva

Re: Regarding COM's Server type(DLL or EXE)

Mike Dimmick14-Jul-07 6:40

Mike Dimmick

14-Jul-07 6:40

DLL-based COM objects will load into the calling application's process. If you implement an EXE server, COM will start your EXE as a separate process. This should be transparent to the calling application. The main difference is that it will take much longer to call code running in another process than code running in your own process.

To actually call code in another process, or another apartment in the same process, COM must marshal the call parameters across the process or apartment boundary. This means writing out all the parameters, and any other areas of memory they reference, to some transport (e.g. a block of shared memory) and somehow signalling the other process that there is a call for it to handle. When the actual function returns, COM must then marshal the results back to the caller. To do this, it has to know the actual data types and whether a pointer represents a string, an array, or just a single object (and if a string or array, how long the string or array is), and whether the parameters are passed in only, passed out only or passed both in and out.

Marshalling can proceed in three ways:

1. The object implements the IMarshal interface;
2. A proxy/stub class is registered for the interface in the registry;
3. A type library is registered to use the Automation marshaller.

Option 3 is really a special case of option 2 - the Automation marshaller is registered as the proxy/stub class. It then looks up the correct type library and uses the information in that to perform the marshalling. This is the most limited option, however. You can only use the Automation data types and structures containing those types. The upside is that scripting languages like VBScript can use your components.

In general, for option 2, you don't actually write your own code for the proxy/stub class. Instead, you define your interfaces in IDL and pass them through the MIDL tool, which generates either tables describing the interfaces or code. The tables have been supported since Windows 98 and Windows NT 4.0, and an update is available for Windows 95 that supports them. All you have to do is build the code into a DLL; Visual Studio generates a project file for you.

COM gets the class factory object for a class implemented in a DLL by calling the DLL's DllGetClassObject function. It cannot call directly into an EXE's code, so the EXE must instead register its class factory objects, for classes that can be created externally, using the CoRegisterClassObject function.

EXE servers are mainly used for implementing OLE and Automation in desktop applications, and where isolation between the client and server is necessary (perhaps for security reasons). If the former, the application typically implements a command-line option (typically /embedding) to indicate that it was launched by COM, not by the user, and to hide its user interface in response.

Finally, it's possible to make a DLL server run in another process if it's registered as a COM+ Server Application. I'm not sure whether doing this with an arbitrary DLL is a good idea, it is probably best to use a component only how the author intended it to be used (as it is unlikely that they have tested other scenarios).

Stability. What an interesting concept. -- Chris Maunder

I am getting 'ICaptureGraphBuilder2' : missing storage-class or type specifiers

yaminisridaran12-Jul-07 19:43

yaminisridaran

12-Jul-07 19:43

I am trying to capture video from web cam.I am using ICaptureGraphBuilder2.
I am getting compilation error
'ICaptureGraphBuilder2' : missing storage-class or type specifiers
'CLSID_CaptureGraphBuilder2' : undeclared identifier

I am using VC6 and visual studio 2003
I have install the directx sdk
I have include the dshow.h
I have included the lib files in project settings.
Quartz.lib Strmiids.lib strmbasd.lib wmvcore.lib wmstub.lib Msvcrtd.libWinmm.lib

I have included the paths in the tools->options->directories

but after doing all this I am getting this compilation error messages. Please any body help me.

S.Yamini

How to Generate OLE dispatch map functions

KASR111-Jul-07 23:01

KASR1

11-Jul-07 23:01

How to Generate OLE dispatch map functions using class wizard or using any other.
please help.

sugest me the basic COM book with C#.Net

help as an alias11-Jul-07 19:00

help as an alias

11-Jul-07 19:00

Hi all,
Thanx in advance.

Re: sugest me the basic COM book with C#.Net

User 21559711-Jul-07 23:04

User 215597

11-Jul-07 23:04

Inside COM - Dale Rogerson[^]

Essential COM - Don Box[^]

COM Interoperability (C#)[^]

You can always read http://www.codeproject.com/com/#Beginners[^]

S o h a i l

modified 21-Apr-21 21:01pm.

This problem is COM related

beloveyyj9-Jul-07 23:03

beloveyyj

9-Jul-07 23:03

1.I am working on win professional xp with regional settings changed to chinese(RPC)
2.I added a custom property in chinese alplabets to a word file from windows explorer.
3.I want to read the Custom Properties of a word file.
4.I got the root storage by StgOpenStorage and finally got the pointer to IPropertyStorage.
5.Now when i read custom property using ReadMultiple, i get invalid characters for the custom Property
6.Note:This happens only for custom properties.
Please let me know the solution of the problem.

Thanks and Regards!

Hands-down one of the best

ir receiver

Waqas Habib9-Jul-07 17:23

Waqas Habib

9-Jul-07 17:23

Hi, i have an ir receiver connected at serial port. i
want to receive signal at serial port using vb.net. is there any sanple code available or any one who can help me.
Thanks

-Waqas

Re: ir receiver

User 2155979-Jul-07 18:52

User 215597

9-Jul-07 18:52

This will help[^]

Please do not post same question on multiple forums. Since it's a VB.net question, post only in VB.NET forum.

S o h a i l K a d i w a l a

To Err Is Human; to Debug, Divine

modified 21-Apr-21 21:01pm.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.