查询矩形范围内的"点"要素

步骤

  1,首先在含有主视图控件 ESRI.ArcGIS.Controls.AxMapControl mapCtrl_main 的主类中定义一个 IEnvelope 成员变量,用于记录鼠标在主视图控件画好的轮廓

 private ESRI.ArcGIS.Geometry.IEnvelope mainInvelope = null; //(主视图上)
public ESRI.ArcGIS.Geometry.IEnvelope MainInvelopeValue {
get {
return mainInvelope;
}
}

并设置成外界可访问的属性.

  2,在该类中定义一bool变量,以控制查询

 private bool startMainInvelope = false; //标识在主视图上画轮廓矩形,以进行该范围内点查询.

  3,在 mapCtrl_main 的 OnMouseDown 响应事件中,控制轮廓的顺畅画好

 if ( == e.button && startMainInvelope) {   //在主视图上画轮廓.
mainInvelope = mapCtrl_main.TrackRectangle();
try {
if (!mainInvelope.IsEmpty)
Engine.App_Code.Draw.DrawSymbol(mapCtrl_main.Map, mainInvelope);
}
catch (System.Exception ex) {
MessageBox.Show(ex.Message);
}
}

其中用到画轮廓的辅助方法定义为:

 /// <summary>
/// 画轮廓.
/// </summary>
/// <param name="sender"></param>
/// <param name="e">根据IEnvelope对象画轮廓.</param>
public static void DrawSymbol(ESRI.ArcGIS.Carto.IMap map, ESRI.ArcGIS.Geometry.IEnvelope e) {
ESRI.ArcGIS.Carto.IGraphicsContainer hawkGC = (ESRI.ArcGIS.Carto.IGraphicsContainer)map;
ESRI.ArcGIS.Carto.IActiveView aView = (ESRI.ArcGIS.Carto.IActiveView)hawkGC;
hawkGC.DeleteAllElements(); ESRI.ArcGIS.Carto.IElement recEle = (ESRI.ArcGIS.Carto.IElement)new ESRI.ArcGIS.Carto.RectangleElementClass();
recEle.Geometry = e;
ESRI.ArcGIS.Display.ISimpleLineSymbol outLine = new ESRI.ArcGIS.Display.SimpleLineSymbolClass();
outLine.Color = ColorPaint(, );
outLine.Width = ; //填充样式.
ESRI.ArcGIS.Display.ISimpleFillSymbol fillSym = new ESRI.ArcGIS.Display.SimpleFillSymbolClass();
fillSym.Color = ColorPaint(, );
fillSym.Outline = outLine; ESRI.ArcGIS.Carto.IFillShapeElement fillShape = (ESRI.ArcGIS.Carto.IFillShapeElement)recEle;
fillShape.Symbol = fillSym;
hawkGC.AddElement((ESRI.ArcGIS.Carto.IElement)fillShape, );
aView.PartialRefresh(ESRI.ArcGIS.Carto.esriViewDrawPhase.esriViewGraphics, null, null);
}

  4,在查询窗口中,用 GetLayerByName 方法定位好待查询的点要素图层(方法定义为)

 /// <summary>
/// 根据图层名获取图层.
/// </summary>
/// <param name="map"></param>
/// <param name="layerName">图层名称.</param>
/// <returns></returns>
public static ESRI.ArcGIS.Carto.ILayer GetLayerByName(ESRI.ArcGIS.Carto.IMap map, string layerName) {
ESRI.ArcGIS.Carto.IEnumLayer enunLayer = map.get_Layers(null, false);
enunLayer.Reset();
ESRI.ArcGIS.Carto.ILayer resultLayer = null;
while ((resultLayer = enunLayer.Next()) != null) {
if (resultLayer.Name.Equals(layerName)) {
break;
}
}
return resultLayer;
}

  5,查询窗口实现查询的所有代码:

 using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms; namespace Engine {
public partial class fQueryInvelopePoints : Form {
private ESRI.ArcGIS.Carto.IMap map = null;
private fMain fMain = null;
public fQueryInvelopePoints(fMain fMain, ESRI.ArcGIS.Carto.IMap map) {
this.fMain = fMain;
this.map = map;
InitializeComponent();
} /// <summary>
/// 查询指定矩形范围内的点要素.
/// </summary>
/// <param name="envelope">指定的矩形范围.</param>
/// <param name="featureClass">待查询的要素.</param>
/// <returns>返回结果的游标</returns>
public ESRI.ArcGIS.Geodatabase.IFeatureCursor GetAllFeaturesFromPointSearchInGeoFeatureLayer(ESRI.ArcGIS.Geometry.IEnvelope envelope, ESRI.ArcGIS.Geodatabase.IFeatureClass featureClass) {
if (featureClass == null)
return null;
ESRI.ArcGIS.Geodatabase.ISpatialFilter spatialFilter = new ESRI.ArcGIS.Geodatabase.SpatialFilterClass();
spatialFilter.Geometry = envelope;
spatialFilter.SpatialRel = ESRI.ArcGIS.Geodatabase.esriSpatialRelEnum.esriSpatialRelEnvelopeIntersects;
spatialFilter.GeometryField = featureClass.ShapeFieldName;
return featureClass.Search(spatialFilter, false);
} private void fQueryInvelopePoints_Load(object sender, EventArgs e) {
Engine.App_Code.Layer_Assist.InitLayers(map, cbox_layer);
} private void btn_query_Click(object sender, EventArgs e) {
lsbox.Items.Clear(); //清空原始数据.
ESRI.ArcGIS.Carto.ILayer lyr = Engine.App_Code.Layer_Assist.GetLayerByName(map, cbox_layer.Text);
if (lyr is ESRI.ArcGIS.Carto.IFeatureLayer) { //矢量数据.
ESRI.ArcGIS.Carto.IFeatureLayer fLyr = (ESRI.ArcGIS.Carto.IFeatureLayer)lyr;
ESRI.ArcGIS.Geometry.IEnvelope selEnvelope = fMain.MainInvelopeValue;
//获取矩形范围内的要素.
ESRI.ArcGIS.Geodatabase.IFeatureCursor fCur = GetAllFeaturesFromPointSearchInGeoFeatureLayer(selEnvelope, fLyr.FeatureClass);
ESRI.ArcGIS.Geodatabase.IFeatureClass fc = fLyr.FeatureClass;
ESRI.ArcGIS.Geodatabase.IFeature f = null;
string v = "";
string k = "";
k = "name";
fMain.mapCtrl_main.ActiveView.Refresh(); //高亮显示前.
try {
while ((f = fCur.NextFeature()) != null) {
map.SelectFeature(fLyr, f); //高亮显示.
v = Convert.ToString(f.get_Value(f.Fields.FindField("name")));
lsbox.Items.Add(k + " : " + v);
}
}
catch (System.Exception ex) {
MessageBox.Show(ex.Message + "不支持查询的图层或查询字段错误:NAME");
}
fMain.mapCtrl_main.ActiveView.Refresh(); //高亮显示后.
}
}
}
}

  6,运行时,画好矩形轮廓后,在主视图控件类中调用即可:

 if (mainInvelope == null || mainInvelope.IsEmpty) {
MessageBox.Show("画轮廓为空");
return;
}
if (fInvelopePoints == null)
fInvelopePoints = new fQueryInvelopePoints(this, mapCtrl_main.Map);
fInvelopePoints.FormClosed += (s, ea) => {
fInvelopePoints = null;
};
fInvelopePoints.Show(this);

其中 fInvelopePoints 为定义在主视图类中的查询窗口的成员变量:

 //查询窗口.
private fQueryInvelopePoints fInvelopePoints = null;

  在主视图中画矩形轮廓如图:查询矩形范围内的"点"要素

  查询后,弹出查询结果如图:查询矩形范围内的"点"要素

上一篇:iosttableViewCell右侧的箭头,圆形等


下一篇:实时数仓入门训练营:实时数仓助力互联网实时决策和精准营销