ESRI.ArcGIS.ADF.IMS
Filter Class
Members  Example  See Also 
ESRI.ArcGIS.ADF.IMS.Carto.Layer Namespace : Filter Class




An object that is used for filtering features.

Object Model


Syntax

Visual Basic (Declaration) 
<SerializableAttribute()>
Public Class Filter
Visual Basic (Usage)Copy Code
Dim instance As Filter
C# 
[SerializableAttribute()]
public class Filter

Example

The following example uses a Filter to highlight land parcels that intersect an envelope and that are valued at over $10,000,000. The land values are in a joined table, so the JoinTables includes the joined table name, and the WhereExpression includes the relationship between the layer's attributes and the joined table.
C#Copy Code
FeatureLayer theLayer = mapView.Layers.FindByName("Parcels"); 

  

Filter theFilter = new Filter(); 

  

// Add the attribute table to the JoinTables collection 

theFilter.JoinTables.Add("DB.map.Parcel_values"); 

  

// Create an envelope to select within 

Envelope selectEnv = new Envelope(556000, 41000, 560000, 43000); 

theFilter.Geometry = selectEnv; 

  

// Select parcels valued over 10,000,000 

theFilter.WhereExpression = "DB.map.Parcels.APN = DB.map.Parcel_values.APN and DB.map.Parcel_values.LandValue > 10000000"; 

theFilter.SearchOrder = SearchOrder.AttributeFirst; 

  

// Create renderer for the highlight layer 

SimpleFillSymbol simpleFill = new SimpleFillSymbol(Drawing.Color.Yellow, Drawing.Color.Yellow, PolygonFillType.DarkGray); 

SimpleRenderer simpleRend = new SimpleRenderer(simpleFill); 

  

// Create the highlight layer 

FeatureLayer hiliteLayer = theLayer.CreateSelectionLayer(theFilter, simpleRend, "parcelSelection"); 

  

mapView.Layers.Add(hiliteLayer); 

    
Visual BasicCopy Code
Dim theLayer As FeatureLayer = mapView.Layers.FindByName("Parcels")



Dim theFilter As New Filter()



' Add the attribute table to the JoinTables collection

theFilter.JoinTables.Add("DB.map.Parcel_values")



' Create an envelope to select within

Dim selectEnv As New Envelope(556000, 41000, 560000, 43000)

theFilter.Geometry = selectEnv



' Select parcels valued over 10,000,000

theFilter.WhereExpression = "DB.map.Parcels.APN = DB.map.Parcel_values.APN and DB.map.Parcel_values.LandValue > 10000000"

theFilter.SearchOrder = SearchOrder.AttributeFirst



' Create renderer for the highlight layer

Dim simpleFill As New SimpleFillSymbol(Drawing.Color.Yellow, Drawing.Color.Yellow, PolygonFillType.DarkGray)

Dim simpleRend As New SimpleRenderer(simpleFill)



' Create the highlight layer

Dim hiliteLayer As FeatureLayer = theLayer.CreateSelectionLayer(theFilter, simpleRend, "parcelSelection")



mapView.Layers.Add(hiliteLayer)

Remarks

A Filter can be used to query a dataset in one of three ways:

  1. A tabular query based on the value of attributes. For example, an attribute query asks for all cities in Canada where the population is greater than 500,000.
  2. A spatial query based on features selected on a map. For example, a rectangle might be dragged over the eastern United States to select a group of cities.
  3. A combination of a tabular and spatial query. For example, a group of cities might be selected, but only cities with a population greater than 500,000 are displayed.


A Filter can also used to join DBF files to shapefiles and to relate tables in ArcSDE.

Inheritance Hierarchy

System.Object
   ESRI.ArcGIS.ADF.IMS.Carto.Layer.Filter

See Also

© 2010 All Rights Reserved.