Re: COM Interop - boxing fault? - C# Discussion Boards

Ungi.1-Mar-04 21:28

1-Mar-04 21:28

I have the following problem:

I use an ocx that provides a method with following parameters (from documentation):

<br />
GetMasSysDataS (<br />
      long parArray(4), <br />
      String startTime,<br />
      String osInfo, <br />
      String sysName,<br />
      String prtNode(2))<br />

The COM interface is created as following:

<br />
short GetMasSysDataS(<br />
      long* parArray, <br />
      BSTR* startTime, <br />
      BSTR* osInfo, <br />
      BSTR* sysName, <br />
      BSTR* prtNode);<br />

I try to use this method in my C# application:

<br />
int[] parArray = new int[4] { -1, -1, -1, -1 };<br />
string startTime = "";<br />
string osInfo = "";<br />
string sysName = "";<br />
string[] prtNode = new string[2] { "", "" };<br />
<br />
// instance the wrapperclass<br />
m_MasDsp = new cominterop.MasDsp ();<br />
/* ... do some configurations ... */<br />
// get the data<br />
m_MasDsp.GetMasSysDataS(ref parArray[0], ref startTime, ref osInfo, ref sysName, ref prtNode[0]);<br />

Almost all data is passed correctly except of the parameters in the array with an index greater than 0.
The first element of the array is correct all other elements stay on initial value.

Has anybody a tip what the problem could be?

[edit]I forgot to post that I had no problems to call that method from a VB6 Application for testing purposes.[/edit]

Re: COM Interop

killerslaytanic1-Mar-04 21:49

killerslaytanic

1-Mar-04 21:49

Just guessing here:

m_MasDsp.GetMasSysDataS(ref parArray, ref startTime, ref osInfo, ref sysName, ref prtNode);

..without the indexes

Re: COM Interop

Ungi.1-Mar-04 21:53

Ungi.

1-Mar-04 21:53

Thanks for your reply!

That doesn't work because of a compiler error:
"Argument '1': cannot convert from 'ref int[]' to 'ref int'"

Re: COM Interop

killerslaytanic1-Mar-04 22:09

killerslaytanic

1-Mar-04 22:09

Another guessing:
also delete the ref for the arrays, (as the arrays vars are references themselves)

m_MasDsp.GetMasSysDataS(parArray, ref startTime, ref osInfo, ref sysName, prtNode);

Re: COM Interop

Ungi.1-Mar-04 22:17

Ungi.

1-Mar-04 22:17

Hallo!

If I do that the following message occurs:
"Argument '1': cannot convert from 'int[]' to 'ref int'"

I think I have already tried almost all combinations of parameter and the one I used seems to be the only one that works.

I wrote a litte VB6-TestingApplication for the dll. There I passed the arrays in the same way as I did in C#.

It is really strange.

Re: COM Interop - boxing fault?

Ungi.1-Mar-04 23:29

Ungi.

1-Mar-04 23:29

Could this be a boxing fault???

Gets "ref parArray[0]" boxed before it is passed to the COM-interface and so the other elements get no values.

Re: COM Interop - boxing fault?

killerslaytanic2-Mar-04 18:58

killerslaytanic

2-Mar-04 18:58

Honestly i don´t know what the hell is going on...Definitively the old C has changed....

Sadly i can´t help you with that one...I´m still "cold" with some features.

Maybe it is a bug but maybe we should study a little more...LOL Smile | :)

If you find the solution could you post it here please?

Re: COM Interop - boxing fault?

Ungi.2-Mar-04 19:07

Ungi.

2-Mar-04 19:07

Of course I will post if I have the solution.

I really think that it is a boxing failure:
I have an array with four elements. To call the method of the ocx I have pass a reference to the first element of the array. But this element is a TypeValue and no reference value. So it is boxed --> put into the heap. But only the first(!!) element!!! So the ocx gets a reference to that element and writes the data into it and also writes data into the next 3 elements. But the other 3 elements aren't in the heap. At the end of the call my first element gets unboxed back into the stack and it has the correct value but the other 3 haven't.

Currently I try to pass through a SAFEARRAY. But there is a lot of studiing because I never used to work with MFC and ClassWizard and so on (only C/C++). But I think I am on the right way!

Problem solved

Ungi.4-Mar-04 20:15

Ungi.

4-Mar-04 20:15

I had to use SafeArrays as described in the msdn.

Datagrid Rows

Reinier van de Wetering1-Mar-04 19:13

Reinier van de Wetering

1-Mar-04 19:13

Is there a way to set the rows of a datagrid to disable row resize??

Method <Summary> descriptions

Reebop1-Mar-04 11:52

Reebop

1-Mar-04 11:52

They show up on the object browser, but not in code view (popup autofill thing) like the core ones. Something I'm doing wrong?

Re: Method <Summary> descriptions

Meysam Mahfouzi1-Mar-04 17:45

Meysam Mahfouzi

1-Mar-04 17:45

You have one project which has been compiled and now you are using it in another project. If you want to see the descriptions for methods and properties, you should just configure your first project before compiling it, so that it also generates the XML documentation file for you. It is, easy just right click on your solution and look for the configuration for xml documentation file. Supply a name for xml file and re-build your project. that is all!

Don't forget, that's

Persian Gulf

not Arabian gulf!

Murphy:
Click Here![^]

I'm thirsty like sun, more landless than wind...

Re: Method <Summary> descriptions

Heath Stewart1-Mar-04 18:15

Heath Stewart

1-Mar-04 18:15

m a y s a m wrote:
that is all!

Not quite. The XML doc has to be in the same directory as the assembly you want to reference (by path, not name).

Microsoft MVP, Visual C#
My Articles

Re: Method <Summary> descriptions

Meysam Mahfouzi1-Mar-04 18:17

Meysam Mahfouzi

1-Mar-04 18:17

That is all! Smile | :)

Don't forget, that's

Persian Gulf

not Arabian gulf!

Murphy:
Click Here![^]

I'm thirsty like sun, more landless than wind...

Re: Method <Summary> descriptions

Reebop1-Mar-04 22:32

Reebop

1-Mar-04 22:32

Thanks!

fog in opengl

shedid1-Mar-04 9:29

shedid

1-Mar-04 9:29

i'm new in programing opengl so.....
I'm heaving troubles implementing the fog function, is it possible for anyone to send me implementation for this function?

M Shedid

Re: fog in opengl

Nick Parker1-Mar-04 9:36

Nick Parker

1-Mar-04 9:36

Try reading 11.7 Other Atmospheric Effects[^] and then look at the Fog Comparison Demo[^] with included source.

- Nick Parker
My Blog

Re: fog in opengl

shedid4-Mar-04 6:55

shedid

4-Mar-04 6:55

thank you , but i want to use fog in a still image, not in animation, is it possible, as if i'm making a scene, so how may i do it? Smile | :)

Client Disconnected.

HAHAHA_NEXT1-Mar-04 8:39

HAHAHA_NEXT

1-Mar-04 8:39

IS there a way to know if the client is disconnected.

My server basically receives data from the client. It uses syncronous connection with a winodw timer (Thus avoiding completly teh multitreading issue.)

Re: Client Disconnected.

Heath Stewart1-Mar-04 9:21

Heath Stewart

1-Mar-04 9:21

This is a very ambiguous question. What client/server technology are you using? A simple TCP socket? .NET Remoting? Web Services? WebRequests? More information would be helpful.

Microsoft MVP, Visual C#
My Articles

Re: Client Disconnected.

HAHAHA_NEXT1-Mar-04 10:52

HAHAHA_NEXT

1-Mar-04 10:52

I am using simple TCP sockets.

Re: Client Disconnected.

Heath Stewart1-Mar-04 10:59

Heath Stewart

1-Mar-04 10:59

Then it depends greatly on your implementation. Some protocols - like DICT - will require that a client - if possible - send a QUIT message (or equivalent) for proper implementation. This tells the server that your client is disconnecting. Otherwise, when your server sends data you should catch any exceptions - which you should be doing anyway - and handle them appropriately. If you get a SocketException, for instance, check the SocketException.ErrorCode for WSAECONNRESET (10054) or WSAENOTCONN (10057). See the Windows Sockets V2 Error Codes[^] on MSDN for more information.

Microsoft MVP, Visual C#
My Articles

Re: Client Disconnected.

RNEELY2-Mar-04 6:38

RNEELY

2-Mar-04 6:38

Open a cmd prompt at your server and type:
netstat -a

Netstat then displays all connections and listening ports.

Check the Microsoft Windows 2000 Server Documentation on Command-line Utilities or type netstat /? for help.

Regards,
-Ron

Sincerely,
-Ron

ServicedComponent: How to tell you are in a transaction?

Le centriste1-Mar-04 8:29

Le centriste

1-Mar-04 8:29

I have a component that supports transactions. One of the method needs to know if it is within a transaction or not. Is there a way to know?

--------

"I say no to drugs, but they don't listen."
- Marilyn Manson

Re: ServicedComponent: How to tell you are in a transaction?

Heath Stewart1-Mar-04 9:18

Heath Stewart

1-Mar-04 9:18

How about ContextUtil.IsInTransaction? There's other related methods for getting the transaction and its ID. Just see the .NET Framework SDK documentation for the System.EnterpriseServices namespace.

Microsoft MVP, Visual C#
My Articles

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