arcengine,深入理解游标Cursors，实现数据的快速查找，插入，删除，更新-白红宇

风过无痕 原文

深入理解游标Cursors，实现数据的快速查找，插入，删除，更新

1、查找数据Search Cursors

//by yl 2008.7.7

IEnvelope envelope = new EnvelopeClass();envelope.PutCoords(508786, 681196, 513033, 684341);ISpatialFilter spatialFilter = new SpatialFilterClass();spatialFilter.Geometry = envelope;String shpFld = featureClass.ShapeFieldName;spatialFilter.GeometryField = shpFld;spatialFilter.SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects;IQueryFilter queryFilter = new QueryFilterClass();queryFilter = (IQueryFilter)spatialFilter;IFeatureCursor searchCursor = featureClass.Search(queryFilter, true);//只查询，true快一些IFeature feature = searchCursor.NextFeature();int n = 0;while (feature != null){    n++;    feature = baseCursor.NextFeature();}

2、插入数据Insert Cursors—目前数据插入最快的方法

//by yl 2008.7.7

IFeatureBuffer featureBuffer = featureClass.CreateFeatureBuffer();IFeatureCursor featureCursor = featureClass.Insert(true);object featureOID;         featureBuffer.set_Value(featureBuffer.Fields.FindField("InstBy"), "B Pierce");for (int ic = 0; ic < 99; ic++) {         featureBuffer.Shape = geometry   featureOID = featureCursor.InsertFeature(featureBuffer);}featureBuffer.set_Value(featureBuffer.Fields.FindField("InstBy"), "K Johnston");for (int ic = 0; ic < 99; ic++){     featureBuffer.Shape = geometry     featureOID = featureCursor.InsertFeature(featureBuffer);}featureCursor.Flush();

3、数据删除 delete

//by yl 2008.7.7

IFeatureClass featureClass = featureWorkspace.OpenFeatureClass("Parcels"); IQueryFilter queryFilter = new QueryFilterClass();queryFilter.WhereClause = "ZONING_S = 'R'";IFeatureCursor updateCursor = featureClass.Update(queryFilter, false);IFeature feature = updateCursor.NextFeature(); int m = 0;while (feature != null){    m++;    updateCursor.DeleteFeature(feature);    feature = updateCursor.NextFeature();}

4、数据更新 update

                                  
//by yl landgis@126.com yanleigis@21cn.com 2008.7.7
IFeatureClass featureClass = featureWorkspace.OpenFeatureClass(
"Parcels"
);
// restrict the number of features to be updated.
IQueryFilter queryFilter = 
new
QueryFilterClass();
queryFilter.WhereClause = 
"ZONING_S = 'U'"
;
 
// use IFeatureClass::Update to populate IFeatureCursor
IFeatureCursor updateCursor = featureClass.Update(queryFilter, 
false
);
int
fieldindex = featureClass.FindField(
"ZONING_S"
);
IFeature feature = updateCursor.NextFeature();
int
m = 0;
while
(feature != 
null
)
{ 
    
m++;
    
feature.set_Value(fieldindex, 
"X"
);
    
updateCursor.UpdateFeature(feature);
    
feature = updateCursor.NextFeature();
}
           
         

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本文转自wenglabs博客园博客，原文链接：http://www.cnblogs.com/arxive/p/6114330.html

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