AEU30: Using Treeviews with Access (Pete Poppe)
In this presentation, Pete Poppe introduced the Treeview control and demonstrated when it can greatly benefit the display of certain types of data within Access applications. In particular, treeviews provide a means of showing hierarchical data in a compact but expandable form. Access does not have a native Treeview control but there are Active X and third-party versions. The presentation included advice on using treeviews and provided a “wrapper” class that makes working with treeviews much simpler.
Download:
Demo database with wrapper class and presentation from: https://isladogs.co.uk/aeu-30
Times:
00:00:00 Welcome from Colin Riddington
00:00:45 Intro by Pete Poppe
00:00:58 Background
00:04:20 Objectives
00:05:04 Agenda
00:05:58 What is a treeview control?
00:06:33 Two types of data - hierarchical & organized
00:07:18 3 custom Access database examples
00:08:22 Terminology
00:09:40 Two free treeview controls - ActiveX/JKP
00:12:27 Access UI Ribbon & Tree Builder
00:12:49 MajP Beta Fake Listbox Treeview
00:13:36 How to use Active X control
00:14:02 How to use JKP control
00:14:13 Need/Utility
00:15:53 Visualize Data & Relationships
00:16:47 ... as Navigation / Combo / List Control
00:17:08 DEMO - Add or edit hierarchical data in treeview - expand/collapse tree or branch; run checks etc
00:18:30 DEMO - Node information - check level/key/index/descendants etc
00:19:26 Large Datasets with more than about 2000 nodes can cause stability issues - only load visible records
00:20:54 DEMO - E2E showing full treeview capabilities - move/renumber/add/remove nodes
00:24:27 DEMO - BOM Tree
00:25:29 Self Referencing Tables
00:26:34 Self Referencing Tables can enforce Referential Integrity
00:27:28 Recursion
00:30:30 Load a tree using Recursion
00:31:31 Trying a treeview to the data
00:33:42 Common Query - allows resusable code
00:34:35 Self referencing example
00:36:57 Organized data example
00:37:38 Tips/tricks
00:38:58 Key Treeview Methods
00:40:44 Treeview form - Wrapper class
00:41:12 Initialize Event
00:42:30 Key Methods from Wrapper Class
00:42:39 Image List - used to show icons - also part of Common Controls library
00:43:33 DEMO - Build Tree from scratch using wrapper class
00:46:42 To edit the treeview control properties, right click on the control and select TreeCtrl Object | Properties . . . OR double click with the treeview control NOT selected
00:47:05 Form VBA code to manage the control properties
00:50:20 Questions: Q1: Eric B - can a split form could be used to combine treeview & listview. No - but possible with a simulated split form
00:51:08 Q2: John B - can a treeview be printed? Can simulate it using report sorting and grouping
00:51:44 Q3: Ken W - wrapper class is excellent - is it in the demo database? YES
00:52:22 Q4: Ken W- An old Windows update caused ActiveX controls to fail - has this been an issue recently? No. Much more stable nowadays.
00:53:34 Discussion: Alessandro G - AG - shouldn't be necessary to register the MSCOMCTL.OCX library file to use the treeview control. Pete disagreed. Is this version dependant?
00:54:35 AG - recommended using recursion to save a lot of code when using treeviews
00:55:18 AG - compared treeview container vs treeview object
00:56:03 Paul S - queried missing PersonID for BossID in slide 28. Does the treeview handle that? Yes - provided Referential Integrity is enforced
00:57:47 Eric B - suggested a 'root record' to prevent issues in the case of an 'absent parent'. Not an issue provided R.I. enforced or mark as unassigned.
01:01:21 Q5: Crystal - is there a character limit for each node? Not but excessively long text might be difficult to read
01:02:11 Bernd B - another treeview control by Thomas Pfoch - https://www.picoware.de/info/treeview...
01:02:37 Many thanks to Pete for an excellent presentation. Links for downloads
01:03:18 Next month: Aleksander Wojtasz - Advanced Techniques with Interactive Gantt Charts - see https://isladogs.co.uk/aeu-31
01:06:37 Final comments. Thanks to our presenter and all those attending. Next meeting - Wed 4 Sept
01:07:42 End