EDN: ESRI Developer Network

IFeatureClass.Search Method

Parameters

filter [in]

  filter is a parameter of type IQueryFilter

Recycling [in]

  Recycling is a parameter of type VARIANT_BOOL

Cursor [out, retval]

  Cursor is a parameter of type IFeatureCursor

    //The following function uses an attribute query and a spatial query to get a subset of the features
    //in a feature class. It then loops through those features and calculates their total area.
    public void IFeatureClass__Search(IFeatureClass featureClass)
    {
        //In this function we will use a spatial filter combined with an attribute query to perform the search.
        //You do not have to perform both types of filters on a search, either could be used individually.

        //Construct an envelope to spatially constrain the search
        //(note: Only high-level geometries, envelopes and geometrybags can be used)
        ESRI.ArcGIS.Geometry.IEnvelope envelope = new ESRI.ArcGIS.Geometry.EnvelopeClass();
        envelope.PutCoords(508786, 681196, 513033, 684341);

        //create a spatial query filter
        ISpatialFilter spatialFilter = new SpatialFilterClass();

        //specify the geometry to query with
        spatialFilter.Geometry = (ESRI.ArcGIS.Geometry.IGeometry)envelope;

        //specify what the geometry field is called on the Feature Class that we will be querying against
        String shpFld = featureClass.ShapeFieldName;
        spatialFilter.GeometryField = shpFld;

        //specify the type of spatial operation to use
        spatialFilter.SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects;

        //create the where statement, in this case we only want the features
        //in the envelope which have a subtype value of "COM"
        spatialFilter.WhereClause = "subtype = 'COM'";
       
        //cast the spatial filter to the IQueryFilter interface
        IQueryFilter queryFilter = new QueryFilterClass();
        queryFilter = (IQueryFilter)spatialFilter;

        //preform the search on the supplied feature class; use a cursor to hold the results
        IFeatureCursor featureCursor = featureClass.Search(queryFilter, false);

        //get the first feature returned
        IFeature feature = featureCursor.NextFeature();
       
        //get the "Area" field
        IFields fields = featureCursor.Fields;
        int areaIndex = fields.FindField("Area");

        //a variable to hold the total area
        Double searchedArea = 0;

        //loop through all of the features and
        //calculate the sum of all of the areas
        while (feature != null)
        {
            searchedArea = searchedArea + (Double)feature.get_Value(areaIndex);
            feature = featureCursor.NextFeature();
        }

        Console.WriteLine("The total area of searched features is {0}", searchedArea);

        System.Runtime.InteropServices.Marshal.ReleaseComObject(featureCursor);
    }

The following example uses an attribute query to get a subset of the features in a feature class. It then loops through those features and calculates their total area.

Dim pFeatcls As IFeatureClass 
Dim pFeatLayer As IFeatureLayer 
Dim pDoc As IMxDocument 
Dim pMap As IMap 

Set pDoc = ThisDocument 
Set pMap = pDoc.Maps.Item(0) 
Set pFeatLayer = pMap.Layer(0) 
Set pFeatcls = pFeatLayer.FeatureClass 

' +++ create the query filter, and give 
' +++ it a where clause 
Dim pQFilt As IQueryFilter 
Dim pFeatCur As IFeatureCursor 

Set pQFilt = New QueryFilter 
pQFilt.WhereClause = "subtype = 'COM'" 
Set pFeatCur = pFeatcls.Search(pQFilt, False) 

' +++ get the area field 
Dim pFlds As IFields 
Dim pFld As IField 
Dim lAIndex As Long 

Set pFlds = pFeatcls.Fields 
lAIndex = pFlds.FindField ("Area") 
Set pFld = pFlds.Field(lAIndex) 

' +++ a variable to hold the total area 
Dim dtotArea As Double 
dtotArea = 0# 

' +++ loop through all of the features and 
' +++ calculate the sum of all of the areas 
Dim pFeat As IFeature 
Set pFeat = pFeatCur.NextFeature 
Do 
dtotArea = dtotArea + pFeat.Value(lAIndex) 
Set pFeat = pFeatCur.NextFeature 
Loop Until pFeat Is Nothing 

' +++ send the total area to a message box 
MsgBox dtotArea