Advanced PowerBuilder

VBX user objects (Only till version 4.0)

PowerBuilder allows you to use Visual Basic v1.0 compatible controls to create user objects. Support of Visual Basic controls gives flexibility, but for that you need to have access to the documentation, otherwise you may end up with the application hanging at run-time. We don't see any PowerBuilder developer using Visual Basic control, since, we are not missing any thing in PowerBuilder that Visual Basic has. Even if you find one, definitely, it won't be from VB V1.0, since the current version of VB is 5.0.

In version 5.0, you can't create a VBX user object. This is because, PowerBuilder now supports OLE 2.0 and OCX controls. VBXes are not available in 32-bit versions, and also, you can find an equivalent version of OCX for it. So, you can use OLE to use OCX. The following is just to give a picture for version 4.0 users. If you are version 5.0 user, you can skip it.

We have a VBX called MCIWNDX.VBX in our Windows directory. We can create a new user object and specify this file:

Once you select the control, it reads all the VBX attributes, and unlike external user objects, you can view and change the attributes in PowerBuilder by selecting "Design/user object Style..."

You can also set these attributes dynamically using PowerBuilder's dot notation. When you create a VBX user object, you automatically acquire the use of the VB events associated with the control, but, you won't be able to see the actual associated code. This makes sense as the code isn't PowerScript.

The attributes you can set for the user object can be accessed from the script painter, by clicking on the Browse Object icon. To see a VBX user object at work, look at the user object uo_1 in the PBEXAMW3.PBL file.

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