What This VBA Code Does
It's unfortunate that the Microsoft developer's did not include a ThisPresentation class in PowerPoint's VBA language. However, there is a way to simulate this functionality by referencing the Presentation's file name. Since users can only have unique file names open simultaneously, this method can serve as an alternative. BEWARE though, because if you change the PowerPoint's file name your macro will not function as intended. But because I'm nice, I'll show you how to put an Error Handler in the VBA code so your user's do not get confused if the name is accidentally changed!
'PURPOSE: Show how to mimic the functionality of ThisPresentation
Dim ThisPresentation As Presentation
Dim ThisFile As String
'What is the name of this file?
ThisFile = "Presentation1.pptx"
'Set Variable to Presentation via Filename
On Error GoTo NotFound
Set ThisPresentation = Application.Presentations(ThisFile)
On Error GoTo 0
'Do Something...(ie add Callout shape to first slide)
ThisPresentation.Slides(1).Shapes.AddCallout msoCalloutOne, 50, 50, 50, 50
MsgBox "There is no file currently opened with the name: " _
& ThisFile & vbNewLine & "Please check to see if the file" _
& " was renamed or modify the VBA code.", vbCritical, "File Not Found"
How Do I Modify This To Fit My Specific Needs?
Chances are this post did not give you the exact answer you were looking for. We all have different situations and it's impossible to account for every particular need one might have. That's why I want to share with you: My Guide to Getting the Solution to your Problems FAST! In this article, I explain the best strategies I have come up with over the years to getting quick answers to complex problems in Excel, PowerPoint, VBA, you name it!
I highly recommend that you check this guide out before asking me or anyone else in the comments section to solve your specific problem. I can guarantee 9 times out of 10, one of my strategies will get you the answer(s) you are needing faster than it will take me to get back to you with a possible solution. I try my best to help everyone out, but sometimes I don't have time to fit everyone's questions in (there never seem to be quite enough hours in the day!).
I wish you the best of luck and I hope this tutorial gets you heading in the right direction!
Chris "Macro" Newman :)