Lesson 4: Working with Maps and Layers

Jim Kompanek

Reflection on Lesson 4

Lesson 4 served as an introduction to programming map and layer objects, as well as automating layer-adding tasks and symbology (Ederlein 2008). The premise of the lesson involved creating a tool to automate the task of adding raster (DOQ) and shapefile (roads) tiles based upon associated index files.

As with the previous lesson, I found that mapping out an outline of all the steps needed was essential prior to beginning the program. The major steps of the first deliverable (DOQ) was to create a custom UIControl, and then tie it to a MouseUp event that triggered a series of procedures. This included (using the code provided in the lesson) “grabbing” the shapefile information that was clicked on and sending it to a separate module to actually pull up the raster. Upon pulling up the raster, it was then necessary to send it to the bottom of the table of contents. In addition, a “cross-like” cursor was assigned to the tool to give visual feedback that the tool was enabled. The second deliverable was essentially the same as the first but instead of pulling up a raster, it was necessary to pull up a road shapefile. As per the instructions, I then symbolized the road as a red, dot pattern.

Overall, I really enjoyed this lesson as it was the first that is directly applicable to own work. While the other lessons served as interesting examples of automating tasks, it was nice to finally create a very “real world” program. In fact, the first deliverable seemed so useful, I'm already in process of adapting it for use in my own office.

References

Enderlein, Timothy

2008 Lesson 4: Working with Maps and Layers. GEOG 485 GIS Programming, Pennsylvania State University. Accessed 29 February 2008.

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