arcgis engine查询系统设计代码

以下是一个简单的ArcGIS Engine查询系统设计代码示例，包括创建地图控件、添加图层、设置查询条件、执行查询以及显示结果等功能：

using ESRI.ArcGIS.SystemUI;
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.Geodatabase;
using ESRI.ArcGIS.ADF.BaseClasses;
using ESRI.ArcGIS.ADF.CATIDs;
using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.Geometry;

namespace ArcGISQuerySystem
{
    public partial class Form1 : Form
    {
        private IMapControl3 mapControl;
        private IFeatureLayer featureLayer;
        private IFeatureLayerDefinition featureLayerDef;
        private IQueryFilter queryFilter;

        public Form1()
        {
            InitializeComponent();
            InitializeMapControl();
            AddFeatureLayer();
        }

        private void InitializeMapControl()
        {
            mapControl = new MapControl();
            mapControl.Dock = DockStyle.Fill;
            panel1.Controls.Add((Control)mapControl);
        }

        private void AddFeatureLayer()
        {
            IWorkspaceFactory workspaceFactory = new ShapefileWorkspaceFactory();
            IWorkspace workspace = workspaceFactory.OpenFromFile(@"C:\data", 0);
            IFeatureWorkspace featureWorkspace = (IFeatureWorkspace)workspace;
            IFeatureClass featureClass = featureWorkspace.OpenFeatureClass("cities");

            featureLayer = new FeatureLayer();
            featureLayer.FeatureClass = featureClass;
            featureLayer.Name = "Cities";

            mapControl.Map.AddLayer((ILayer)featureLayer);
        }

        private void btnQuery_Click(object sender, EventArgs e)
        {
            string cityName = txtCityName.Text;
            string queryExpression = "CITY_NAME = '" + cityName + "'";
            queryFilter = new QueryFilter();
            queryFilter.WhereClause = queryExpression;

            featureLayerDef = (IFeatureLayerDefinition)featureLayer;
            featureLayerDef.DefinitionExpression = queryExpression;

            mapControl.Map.ClearSelection();
            mapControl.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);

            IFeatureCursor featureCursor = featureLayer.FeatureClass.Search(queryFilter, true);
            IFeature feature = featureCursor.NextFeature();

            while (feature != null)
            {
                mapControl.Map.SelectFeature(featureLayer, feature);
                feature = featureCursor.NextFeature();
            }

            mapControl.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeoSelection, null, null);
        }
    }
}

在该示例中，我们首先创建了一个地图控件，并将其添加到 Windows 窗体中的一个面板中。接着，我们从一个 Shapefile 工作空间中打开一张名为 “cities” 的城市要素类，并将其添加到地图控件中作为一个矢量图层。然后，我们在查询按钮的点击事件中构造一个查询表达式，并将其设置为图层的筛选条件，以实现按城市名查询的功能。最后，我们使用 IFeatureCursor 对象遍历查询结果，并将查询到的要素在地图控件中高亮显示出来。