Change CreateObject during Migration

27. March 2009 13:18 by Mrojas in General  //  Tags: , , , , , , , , ,   //   Comments (0)

One of our clients wanted to change the CreateObject function migration for a function of their own. So they wanted all cases like:

Dim x As Object
Set x = CreateObject("Excel.Application")

 

To be migrated to something like:

Excel.Application x = (Excel.Application) Utils.MyCreateObject("Excel.Application", "");

Our migratio vb6migration tool provides a new cool feature called CustomMaps. This feature allows you to provide some simple but useful changes to the way things get migrated.

For this case follow these steps:

1. Open the Visual Basic Upgrade Companion.

2. In the Tools Menu choose:

image

3. Create a new CustomMaps File and an an entry like the following:

 

image

Notice the Source name is VBA.Interaction.CreateObject. To find out this name you can look in your VB6 IDE, right click on the CreateObject and select goto Definition. 
image 
 
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and for the target name just put the implementation that you what, for example you can write a function like:
class Utils
        {
            public static object MyCreateObject(string className,params object[] ignoreRestParams)
            {
                return Activator.CreateInstance(Type.GetType(className));
            }
        }

and set the SourceName to Utils.MyCreateObject (or NameSpace.Utils.MyCreateObject to use the fully qualified name). You just need to set the New Reference Name column because we will not change the definition of the function.