Monday, March 30, 2009

ArcPad Tips & Tricks #2: Multiple layer definitions

Did you know that the AXF file format supports multiple layer definitions for a single feature class? This works in the same way as Layer files in ArcMap: the layer defines the symbology, which points to a feature class, which stores all of the data (both spatial and attributes). To set this up in ArcPad:
  1. Open the AXF in ArcPad studio
  2. Expand the Feature Tables node
  3. Right click on the table you wish to create the layer definition for, and select "Create New Layer". A new layer definition is added to the Feature Layers node
  4. You can rename the layer to whatever you like

And how is this useful I hear you ask. Well, a couple of ideas are:

  1. You could create different edit forms for different purposes. For example, you may have a layer for new features that are collected, and one for follow up inspections. You can specify different forms to ensure the correct fields are filled out in each inspection.
  2. You can combine the layer definitions with filters to create more complex symbology. For example, you may wish to categorise your roads layer into suburban roads, major roads and highways, and display them at different zoom scales.

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