Trim unique values

Purpose

This sample updates unique values symbology for a layer based on values in the current layer data source. This sample trims (removes) values from the layer's unique values renderer. The options for this are as follows:

Trim all values not present in the current layer data source
Trim all values not present in the current extent for the layer

This sample automates the process of removing values from a unique values symbology without disturbing the match between each individual value and symbol. In ArcObjects terminology, values are removed from the UniqueValuesRenderer if they are not present in the current data (or current extent). Removing values from the renderer means that they will no longer appear in the ArcMap table of contents (TOC) or legend. This is particularly useful in the following scenarios:

To see only values present in the current extent
If the data behind the layer has been edited
If the layer points to new data (a new feature class)
To synchronize unique values after importing symbology from a layer file (.lyr)

The logic only removes values from the renderer, it does not add new values to the renderer that it might find in the feature class or extent.

How to use

See How to use ArcGIS samples for help running the sample.

1. Run the application.

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Development licensing	Deployment licensing
Engine Developer Kit	Engine Runtime
	ArcView