HI,

 I'm evaluating XceedZipCompression Library 6.5 .Net trial version through .net wrapper 'Interop.XceedzipLib (version 5.4.0.0)'. The library was working fine till last moment, when received .net exception describing the failure of the 'Uncompress' method. The exception details are as follows;

I'll appreciate to know the cause and solution if any to avoid this failure ahead. 

The exception details:  

 System.InvalidCastException: unable to cast COM object of type 'XceedZipLib.XceedCompressionClass' to interface type  ''XceedZipLib.IXceedCompression'.  The operation failed because the QueryInterface call on the COM component for the interface with IID '{772443A10-00F3-11D5-802D-0060082AE372}' failed due to the following error : unspecified error ( Exception from HRESULT: 0x80004005 (E_FAIL) ) at XceedZipLib.XceedCompressionClass.Uncompress( object & vaSource, object & vaUncompressed, Boolean bEndOfData)

Code snippet from my code is :

xcdCompressionError error = xceedObject.Uncompress(ref sourceObj, out uncompressObj, true);                    

where...    xceedObject is an object of 'XceedCompressionClass', whereas sourceObj and uncompressObj are of type object.

Note:

1. I'm calling  License() method prior calling any other method from class XceedCompressionClass.
2. Environment using - VS2008 / .Net 3.5 SP1, winXP/SP3

Regards,

Prashant.

Hi,

We have seen this error before, it is related to the .NET COM wrapper and not to Xceed.

How do you declare the XceedCompression object? Try changing it to the folowing:

XceedCompression xceedObj = new XceedCompressionClass();

Our experience has shown that this way works best.

We know it seems like a useless change but it's the arrangement that has gotten us the best results when calling methods and properties.

Regards,

Alain Jreij,

Xceed Technical Support