System.InvalidCastException problem

[klunde]

Hi

I have a C# program that I haven't written my self, but I have it running on a server here. Now I've opened the source on my computer (and upgraded the project without error to VS 2008). Then I've changed two small lines in the code and re-compiled it (again without error). But when I run the new exe file on my server I get the following error:

(System.InvalidCastException: Unable to cast COM object of type 'System.__ComObject' to interface type 'ADBInterfaceDLL.ArticleDataBase'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{81B80D72-77C9-4C70-A7C2-20A80BDB83BC}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).

The file ADBInterfaceDLL is located in my project and is only 4096 bytes large. I have the same version on my computer as on the server.

Any idea why I get this error?

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[phinoppix]

Is the com-dll properly registered on your machine? It seems that you only have the com interop dll, but the actual com-dll is not yet registered.

 

[klunde]

No it wasn't. I finally found the component under COM+ applications on my server. I exported it and installed it into COM+ on my dev. machine. Then I removed the components (adbinterfacedll and adodb.dll) from my project and added them again from the COM page on the references in VS.

Now my new problem is that when re-compiling it now uses interop.adodb.dll instead of adodb.dll as it used to. This again gives me a new error message:

System.Runtime.InteropServices.COMException (0x800A0BBC): Write to file failed.
at ADBInterfaceDLL._ArticleDataBase.GetData(Int32& lngExtKey, String& strSupplierName, String& strArticleFormat, Recordset& rsRecordset, String& strErrorMessage)
at WebClip2.PDFWorker.DownloadPDF(Int64 ArticleID, String FileName) in C:\Data\Source\WebClip\WebClip.2.3.0.5\PDFWorker.cs:line 59\n)

And I can't really see why. I haven't changed the code part here.


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[phinoppix]

It looks like its able to consume the COM object now, but you're getting what seems to be an i/o exception, like a write permission or file integrity problem. you must have missed something else required by your project, check the com's docs if any.

 

[klunde]

If only there where some docs....

Here is the code part where I get the error. I can't really understand why I get a "write to file" error when I'm actually trying to read data.

try 
{
	ADBInterfaceDLL.ArticleDataBase ADB = (ADBInterfaceDLL.ArticleDataBase)obj;
	ADODB.Recordset RS = new ADODB.RecordsetClass();
	ADODB.Stream st = new ADODB.StreamClass();
				
	string sSupplierName = "Native";
	string sArticleFormat = "PDF_WholeArticle";
	int lIdentifier =  Convert.ToInt32(ArticleID);
	string sDestination = FileName;

//The next line is #59 and the one that failes according to the error message
	ADB.GetData(ref lIdentifier, ref sSupplierName, ref sArticleFormat, ref RS, ref sErrorMessage);
	if(sErrorMessage != "" && sErrorMessage !="Default")
		return sErrorMessage;

	st.Type = ADODB.StreamTypeEnum.adTypeBinary;
	st.Open(Type.Missing, ADODB.ConnectModeEnum.adModeUnknown, ADODB.StreamOpenOptionsEnum.adOpenStreamUnspecified, "", "");

	st.Write(RS.Fields[0].Value);

	st.SaveToFile(sDestination, ADODB.SaveOptionsEnum.adSaveCreateOverWrite);
} 
catch (Exception ex) 
{
	ExceptionManager.Publish( ex );
	return ex + @"\n" + sErrorMessage;
} 
return "OK";

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[klunde]

Additional info:

On the server I'm running this program on I have the older compiled version of the program. This version works ok. There is no write to file errors or anything with that one, but if I start the one I have compiled I get this error.

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