We continue with.. how to develop ArcGIS.... Pt2
In today’s blog we take a closer look at the building blocks for ArcGIS and also how to develop custom applications for your projects.
The core of ArcGIS and any customization is ArcObjects, which can be developed via several APIs (VB, VC++, Delphi, Mainwin, C#, VB.NET). The APIs are mainly either COM based or dotNET.
The first thing you have to do as an ArcGIS (ArcObjects) developer is to look at the ArcObjects Class Diagrams. These class diagrams provide useful insight into ArcObject’s model and implementation. In addition to the class diagrams provided as PDF files, you can use the Microsoft object browsers like OLEView or the ESRI Object Viewer. These object browsers can view the coclasses and methods within the ArcObjects model.
One of the fundamental or most common pitfalls among ArcObject programmers is to ensure optimal coding when working with databases and GIS data storage. There are strict rules to follow to avoid data or application corruption. If you want the application to perform inserts, updates and deletes… you need to make sure there is an Edit Session running, which turns on a behaviour in the geodatabase for proper edit transactions.
One of the ways I started with ArcObjects is to customize in a VBA environment. I feel it’s the best place to start if we wanna learn or master ArcObjects development. VBA is used for many years in Excel, MS Access and MS Word to customize its interface right up to full blown applications. There are some reasons why we should start with VBA:
* Its fast to create, test and debug inside ArcMap and ArcCatalog.
* The standard libraries and classes for ArcObjects have already been referenced and added
* Global variables that reference ArcMap, ArcCatalog and the Application are available
* You can create fast and reliable VB Forms using VBA and Active-X components. You can also add new Active-X components or Microsoft objects
So start your first ArcObjects application in ArcMap and have loads of fun developing ;-)