ActiveReports Upgrade Error

Question

I just upgraded from ActiveReports 2.0 to 3.0. All rpx files have been converted to *.vb files. The ActiveReports project has this class hierarchy:

*.vb with designer -> PrintBase.vb -> ActiveReport3

When I opened any of the *.vb files, I got this error:

The designer could not be shown for this file because none of the classes within it can be designed. The designer inspected the following classes in the file: xxx --- The base class 'PrintBase' could not be loaded. Ensure the assembly has been referenced and that all projects have been built.

Call stack: at System.ComponentModel.Design.Serialization.CodeDomDesignerLoader.EnsureDocument(IDesignerSerializationManager manager) at System.ComponentModel.Design.Serialization.CodeDomDesignerLoader.PerformLoad(IDesignerSerializationManager manager) at Microsoft.VisualStudio.Design.Serialization.CodeDom.VSCodeDomDesignerLoader.PerformLoad(IDesignerSerializationManager serializationManager) at System.ComponentModel.Design.Serialization.BasicDesignerLoader.BeginLoad(IDesignerLoaderHost host)

Then I went through PrintBase.vb. There was no compile error. Then I modified one of the *.vb files to this:

Hello.vb -> ActiveReport3

The designer worked without any problems. The PrintBase has quite a bit of code. To simplify the debugging, I created a new .vb file called BasePrint that inherits from ActiveReport3. So, the hierarchy is back to:

Hello.vb -> BasePrint -> ActiveReport3

Then I saw the same error above again. It seems like AR3 designer does not allow .vb files to inherit from a base class according to my debugging. But I am not quite sure. BTW, the ActiveReports project is vb.net. There are other C# projects under a VS 2008 project solution. Is the mixing of VB.NET projects and C# have anything to do the miagration / upgrade process?

Thanks.

Answer 1

Indeed, the class-style inheritance was not supported by the upgrade utility in the ActiveReports 3.x designer. However, after an upgrade is complete you should be able to put the base class bad (the way that you described) and the designer should safely ignore it. If you're still having problems try to close the project, do a clean (delete the old assemblies that might be referncing the old PrintBase class) & close visual studio and reopen it again to get a fresh start.

You can find more information about upgrading reports from ActiveReports 2.x to ActiveReports 3.x at the following page: link text

However, it seems you are using inheritince in this case to share some utility methods and maybe some state (e.g. in class-level fields maybe). For this it is best if you have your reports inherit directly from ActiveReport3 and use "BasePrint" as a sort of utility class that your reports call functions in. Normally this has no disadvantage other than having to prefix the method calls with the name of the corresponding BasePrint instance/variable name and it simplifies dealing with ActiveReports designer in the scenario you describe.

However, ActiveReports does support a visual inheritence that allows a base report to share controls with a derived report. There is more information on how to use this feature at the following location: http://www.datadynamics.com/Help/ARNET3/ar3tskInheritance.html. However, I want to stress that this is a different style of inherience than you are using so it may not be applicable to what you need.

Also, you should try to convert again without having a combined solution with C# and VB projects. I don't know that this is a problem but it is certainly not the most common way the converter is used and may be complicating things.

Finally, you should be aware that ActiveReports 6 is now available and you may want to consider trying out that version.

If you continue to have any problems please contact our support team at [email protected] or use our public forms that have many ActiveReports experts monitoring them every day at the following links:

http://www.datadynamics.com/forums/73/ShowForum.aspx - ActiveReports 3 Forum http://www.datadynamics.com/forums/82/ShowForum.aspx - ActiveReports 6 Forum

Scott Willeke
GrapeCity / Data Dynamics