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SoapException in C# Web Service that references COM object

Nxorable17-Jul-07 2:56

17-Jul-07 2:56

I have created a ActiveX DLL in Visual Basic 6.0 SP5 with one function that returns a String of "Hello World From VB6 DLL". I then register the DLL using RegSvr32 <path and file name of VB6 DLL>. Next, I create a new WebService project in C# using Visual Studio 2005 .NET. In this project, I do an Add Reference, choose the COM tab, and select the DLL I just created in VB6. I add a using directive (using VB6ComTest;) to my Web Service class then proceed to add WebMethod that will call that VB6 function:

[WebMethod]
public string GetTestString()
{
VB6ComTest.MyVBTestClassClass test = new MyVBTestClassClass();
string a = test.HelloWorld();

return a;
}

I'm new to Web Services and using Interop in .NET. I've read that Interop uses interfaces so that may explain why the "Class" is named "MyVBTestClassClass". The intellisense is showing me three (3) items within VB6ComTest and they are: _MyVBTestClass (an interface), MyVBTestClass (an interface), and finally MyVBTestClassClass (a class).

When calling the this GetTestString() WebMethod from Internet Explorer (using the .asmx) or from a console application I have created in the same solution, I get this error every single time without fail:

System.Web.Services.Protocols.SoapException was unhandled
System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.InvalidCastException: Unable to cast COM object of type 'VB6ComTest.MyVBTestClassClass' to interface type 'VB6ComTest._MyVBTestClass'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{9F789AFC-7C61-4D4F-8EDF-35866D18EEEE}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).\n at VB6ComTest.MyVBTestClassClass.HelloWorld()

I've been battling this for three full work days now and would great appreciate any assistance.

Thank you.

Jason

Re: SoapException in C# Web Service that references COM object

led mike17-Jul-07 4:38

led mike

17-Jul-07 4:38

Nxorable wrote:
Next, I create a new WebService project in C# using Visual Studio 2005 .NET.

Nxorable wrote:
I've been battling this for three full work days now and would great appreciate any assistance.

Have you created a C# Winforms project and used the ActiveX control successfully in there?

Re: SoapException in C# Web Service that references COM object

Nxorable17-Jul-07 4:47

Nxorable

17-Jul-07 4:47

Thanks for your reply.

Yes, I have tried directly referencing the DLL in the Console application and it works fine. I have also created a .NET class library that wraps this VB6 DLL and then referenced the the .NET library from the Console app and that work fine too. The moment I try to reference the VB6 DLL from a .NET Web Service, I get this exception.

I've done a lot of research online and in Wrox books with no success. I've verified that ASP.NET and the IUSER account on my box have access to the COM library as well as the HKCR registry keys. I've registered and unregistered the DLL numerous times.

Re: SoapException in C# Web Service that references COM object

led mike17-Jul-07 5:04

led mike

17-Jul-07 5:04

Well, if you are executing the "exact" same code in the Web Service that works in the console application then obviously the difference is the context. This means some problem like security, access/permissions, registry, etc.

how to embed word in windows form

lockepeak17-Jul-07 2:53

lockepeak

17-Jul-07 2:53

I have a project write in c# (c/s) need to embed word controler
that is to say, the combox is used word controler instead. so that is free to edit content.

Re: how to embed word in windows form

originSH17-Jul-07 2:55

originSH

17-Jul-07 2:55

lockepeak wrote:
the combox is used word controler instead

You mean you want a combo box in which you can type and change the value? Thast the default functionality when you add a new combo box.

Re: how to embed word in windows form

lockepeak17-Jul-07 3:06

lockepeak

17-Jul-07 3:06

I want to embed the word in the windows form.

Re: how to embed word in windows form

Colin Angus Mackay17-Jul-07 3:11

Colin Angus Mackay

17-Jul-07 3:11

lockepeak wrote:
I want to embed the word in the windows form.

That still isn't understandable.

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Re: how to embed word in windows form

Bert delaVega17-Jul-07 4:14

Bert delaVega

17-Jul-07 4:14

Sounds like you want to use rich text features in a control. Take a look at this project: http://www.codeproject.com/vb/net/WordProcessingPackage.asp[^]

It's vb.net but could point you in the right direction. I use it in one of my c# projects and it works just fine.

Re: how to embed word in windows form

Dan Neely17-Jul-07 4:58

Dan Neely

17-Jul-07 4:58

There's an MS Word COM control you could use. It requires that Word be installed on the users machine, and IIRC it's version specific so you'd need to build a separate app for each version of word your clients use. Also it only provides a limited subset of the toolbar and menu options with AFAIK no way to change them. You can find more information via google.

--
You have to explain to them [VB coders] what you mean by "typed". their first response is likely to be something like, "Of course my code is typed. Do you think i magically project it onto the screen with the power of my mind?" --- John Simmons / outlaw programmer

Re: how to embed word in windows form

lockepeak17-Jul-07 20:32

lockepeak

17-Jul-07 20:32

thank you all of you.lockepeak

Changing the background

razanabanu17-Jul-07 2:33

razanabanu

17-Jul-07 2:33

im woking with web forms....I would like to change the backround of web form at run time....how can I achieve that?...

Hi,Im Razana

Re: Changing the background

Malcolm Smart17-Jul-07 3:05

Malcolm Smart

17-Jul-07 3:05

Hi, I'm Malcolm

I thought this was gonig to be easy to answer...but unless somebody wants to make me look stupid, it isn't that straight forward. Try this...

Change your <body> tag

<body id="bodytag" bgColor= "#000099" runat="server">

and then in the event handler that is called to change the colour (or on PageLoad) call :

bodytag.Attributes.Add("bgcolor", "#EE33AA");

obviously setting which ever colour you want.

Is there a better / different way anybody? I never change the background color!

"More functions should disregard input values and just return 12. It would make life easier." - comment posted on WTF

Re: Changing the background

Vasudevan Deepak Kumar17-Jul-07 4:41

Vasudevan Deepak Kumar

17-Jul-07 4:41

Style?

Vasudevan Deepak Kumar
Personal Homepage
Tech Gossips

Threading ???

Software_Specialist17-Jul-07 2:31

Software_Specialist

17-Jul-07 2:31

Hi all,

I am writing an application in which i have a loop to write some outputs over the text box .After i run the application, it works fine as long as i stick to the form and do not click anywhere. As soon as i open any other window to work on and then go back to that output form..It freezes the application and doesnt respond.

The code for instance is as shown below...

  <br />
//On BUTTON CLICK the word "Message" repeats in every line until loop ends....<br />
while (true)<br />
{<br />
  if(count > 1000)<br />
  {<br />
    break;<br />
  }<br />
<br />
  Thread.Sleep(1000)<br />
  TextBoxA.Text += "Message" + Environment.NewLine;<br />
  TextBoxA.Refresh();<br />
  count++;<br />
<br />
}//end while<br />

I guess its something to do with threading...But i am not too sure about it. Pls point me the right direction....

Thanks
SS

Re: Threading ???

originSH17-Jul-07 2:41

originSH

17-Jul-07 2:41

For windows forms in .net 2.0 you can use the BackgroundWorker[^] control. You place it on the form and then put your code into the Do Work event.

If you need to do this in .Net 1.1 or outside of win forms then you can use the Thread Class[^] directly.

To do this you make a new method which takes no parameters and has no return value:

private void TestThread()
{
//DO STUFF
}

Then you create a new thread and start it:

System.Threading.Thread testThread = new System.Threading.Thread(new System.Threading.ThreadStart(this.TestThread));
testThread.Start();

You can also pass things to the thread but I'll leave that for you to read up on Wink | ;)

One last thing to note, if you are working with windows forms then you'll need to use the Invoke method on any controls you access across threads.

http://www.codeproject.com/csharp/threadsafeforms.asp[^]

Re: Threading ???

Software_Specialist17-Jul-07 3:31

Software_Specialist

17-Jul-07 3:31

hey thanks for your reply...
I have added this backgroundWorker and copied the code to backgroundWorker1_DoWork event. Now how can i call this backgroundWorker1_DoWork under btn pressed event to execute the loop...??

Thanks

Re: Threading ???

Bekjong17-Jul-07 3:46

Bekjong

17-Jul-07 3:46

Generally, it works like this:

System.ComponentModel.BackgroundWorker bw = new System.ComponentModel.BackgroundWorker();
bw.DoWork +=new System.ComponentModel.DoWorkEventHandler(bw_DoWork);
bw.RunWorkerAsync();

But why not look at the MSDN example?

Standards are great! Everybody should have one!

Re: Threading ???

Software_Specialist17-Jul-07 4:20

Software_Specialist

17-Jul-07 4:20

Dont know ..its bit confusing at the moment. Well i am getting exception Cross-threaded operation not valid..
I am trying to achieve simple operation that is execution of the code i mentioned in my first post.
I just have one textbox and a button over the form. Now i added backgroundWorker component over the form. Double clicked over DoWork event.

Now i have a startbtn click and DoWork event. So do i need ProgressChanged or RunWorkerCompleted event or no..??

If not then do i have to just paste the first post code under DoWork event and add some extra code under start button event to execute the loop or is there any different approach. If its true then what would be that extra code that i have to add under start button event so that it performs what i am trying to...
I dont think it works with
backgroundWorker1.RunWorkerAsync(); .........?

Well in MSDN they have given some differnt example and i am doing something really simple...

Thanks

Re: Threading ???

Bekjong17-Jul-07 4:48

Bekjong

17-Jul-07 4:48

So do i need ProgressChanged or RunWorkerCompleted event or no..??

Yes. You're getting the Crossthreading exceptions because you're trying to do an operation on a thread other than the thread the UI control was created on. This isn't allowed in forms. You can use ProgressChanged and RunWorkerCompleted to avoid this. Use the ReportProgress together with the ProgressChanged event to achieve this:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        BackgroundWorker bw = new BackgroundWorker();
        public Form1()
        {
            InitializeComponent();
            
            bw.WorkerReportsProgress = true;
            bw.DoWork += new DoWorkEventHandler(bw_DoWork);
            bw.ProgressChanged += new ProgressChangedEventHandler(bw_ProgressChanged);
            bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bw_RunWorkerCompleted);
            bw.RunWorkerAsync();
        }

        

        void bw_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            this.Text = "Looped " + e.ProgressPercentage + " times";
        }

        void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            this.Close();
        }

        void bw_DoWork(object sender, DoWorkEventArgs e)
        {
            int i = 0;
            while (i++ < 100)
            {
                bw.ReportProgress(i);
                Thread.Sleep(100);
            }
        }
    }
}

Standards are great! Everybody should have one!

Re: Threading ???

Russell Jones17-Jul-07 5:02

Russell Jones

17-Jul-07 5:02

cross-threaded operation etc. is caused by controls being updated by any thread other than the one that created them. The background worker control should stop this. Otherwise you need to call begininvoke on the control that you are updating. There are loads of examples of this on CP and MSDN.

Russ

Could yous give some idea ?

LyBun17-Jul-07 2:31

LyBun

17-Jul-07 2:31

I do my homework. and I met this.
there are 3 forms in the project. in the 3 one is the main form 2 is the sub. and in the sub form I want to use some variable in the main form. for example in the main for have a connection object variable when the main form loaded the connection object created. and I open another one sub form and I also want to use the main form's connection object. and I do know how to do it.(all this I do it in C#)
Please give me some idea!
thanks!

Re: Could yous give some idea ?

Malcolm Smart17-Jul-07 2:56

Malcolm Smart

17-Jul-07 2:56

Hi - search the forums. This question must be posted at least once a week.

Try clicking here...[^]

"More functions should disregard input values and just return 12. It would make life easier." - comment posted on WTF

Re: Could yous give some idea ?

Colin Angus Mackay17-Jul-07 3:10

Colin Angus Mackay

17-Jul-07 3:10

See this article on passing values between forms (or any related classes for that matter): http://www.codeproject.com/dotnet/passingvaluesbetweenforms.asp[^]

Double row in TreeView or ListView

Andrea_8617-Jul-07 1:51

Andrea_86

17-Jul-07 1:51

Has someone already create a TreeView control (or a listview with tile style) with the possibility to insert an element (node or row) with double row? (like the windows xp's explorer on certain type of file)

I explain better Poke tongue | ;-P

open explorer, go in a folder with some MP3s, set the view in Tile (title) mode: All files are rapresented with more than one row (filename in the first; artist in the second and album in the third)...
i have to do a listview like this!!

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