ArcGIS Engine二次開發——計算shapefile面圖層要素的面積 http://blog.csdn.net/giselite/article/details/44750349
全部都應該學會看AE的類圖和協助，尤其是類圖，在安裝目錄下的Diagram目錄裡，看多了自然就會得心應手。廢話不多說了，下面是我寫的一段實驗代碼
，公布一下，希望能協助那些有需求的童鞋，給他們節省點時間。
using System.Runtime;
using System.Runtime.InteropServices;
using ESRI.ArcGIS.Geodatabase;
using ESRI.ArcGIS.DataSourcesFile;
using ESRI.ArcGIS.Geometry;
private void Form1_Click(object sender, EventArgs e)
{
IWorkspaceFactory pWSF = null;
double dArea = 0;
try
{
pWSF = new ShapefileWorkspaceFactoryClass();
IFeatureWorkspace pWS = pWSF.OpenFromFile(@"H:\水體淹沒面積", 0) as IFeatureWorkspace;
IFeatureClass pFC = pWS.OpenFeatureClass("水體淹沒面積專題.shp");
IFeatureCursor pFeatureCur = pFC.Search(null, false);
IFeature pFeature = pFeatureCur.NextFeature();
while (pFeature != null)
{
if (pFeature.Shape.GeometryType == esriGeometryType.esriGeometryPolygon)
{
IArea pArea = pFeature.Shape as IArea;
dArea = dArea + pArea.Area;
}
pFeature = pFeatureCur.NextFeature();
}
Marshal.ReleaseComObject(pFeatureCur);
}
catch (System.Exception ex)
{
}
Marshal.ReleaseComObject(pWSF);
}
========
6.5 IProximityOperator介面 http://www.cnblogs.com/gisoracle/archive/2012/03/28/2420706.html
6.5.1 IProximityOperator介面簡介
IProximityOperator介面用於擷取兩個幾何圖形的距離，以及給定一個 Point，求另一個幾何圖形上離離給定點最近的點。IProximityOperator介面的主
要方法有：QueryNearesPoint,ReturnDistance, ReturnNearestPoint
ReturnDistance方法用於返回兩個幾何對象間的最短距離，QueryNearesPoint方法用於查詢擷取幾何對象上離給定輸入焦點的最近距離的點的引用，
ReturnNearestPoint方法用於建立並返回幾何對象上離給定輸入焦點的最近距離的點。
6.5.2 最近點查詢功能開發
以下程式碼片段示範如何使用IProximityOperator介面擷取給定點與要查詢的幾何圖形的最近點：
/// 在pGeometry上返回一個離pInputPoint最近的point
/// </summary>
/// <param name="pInputPoint">給定的點對象</param>
/// <param name="pGeometry">要查詢的幾何圖形</param>
/// <returns>the nearest Point</returns>
private IPoint NearestPoint(IPoint pInputPoint, IGeometry pGeometry)
{
try
{
IProximityOperator pProximity = (IProximityOperator)pGeometry;
IPoint pNearestPoint = pProximity.ReturnNearestPoint(pInputPoint, esriSegmentExtension.esriNoExtension);
return pNearestPoint;
}
catch(Exception Err)
{
MessageBox.Show(Err.Message, "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
return null;
}
}
複製代碼
以下程式碼片段示範如何使用IProximityOperator介面查詢給定的兩個幾何對象的距離：
/// <summary>
/// 擷取兩個幾何圖形的距離
/// </summary>
/// <param name="pGeometryA">幾何圖形A</param>
/// <param name="pGeometryB">幾何圖形B</param>
/// <returns>兩個幾何圖形的距離</returns>
private double GetTwoGeometryDistance(IGeometry pGeometryA, IGeometry pGeometryB)
{
IProximityOperator pProOperator = pGeometryA as IProximityOperator;
if (pGeometryA!=null|| pGeometryB !=null)
{
double distance= pProOperator.ReturnDistance(pGeometryB);
return distance;
}
else
{
return 0;
}
}
========
空間關係(計算兩點間距離、計算範圍) http://xitong.iteye.com/blog/1715755
計算兩點間距離
1 /// <summary>計算兩點間距離
2 /// </summary>
3 /// <param name="point1"></param>
4 /// <param name="point2"></param>
5 /// <returns></returns>
6 public static double getDistanceOfTwoPoints(ESRI.ArcGIS.Geometry.IPoint point1, ESRI.ArcGIS.Geometry.IPoint point2)
7 {
8 return Math.Sqrt((point1.X - point2.X) * (point1.X - point2.X) + (point1.Y - point2.Y) * (point1.Y - point2.Y));
9 }
feature平移
1 IGeometry geo＝feature.Shape;
2 ((ITransform2D)geo).Move(20,20);
計算範圍
得到點集合的n倍Envelope範圍
1 /// <summary>得到點集合的n倍Envelope範圍
2 /// </summary>
3 /// <param name="points"></param>
4 /// <param name="zoomInNumber"></param>
5 /// <returns></returns>
6 public static IEnvelope getBigEnvelope(IPointCollection points, double zoomInNumber)
7 {
8 IEnvelope result = new EnvelopeClass();
9
10 double xmax = 0, xmin = 999999999999, ymax = 0, ymin = 999999999999;
11
12 for (int i = 0; i < points.PointCount; i++)
13 {
14 ESRI.ArcGIS.Geometry.IPoint p = points.get_Point(i);
15 if (xmax < p.X) xmax = p.X;
16 if (ymax < p.Y) ymax = p.Y;
17 if (xmin > p.X) xmin = p.X;
18 if (ymin > p.Y) ymin = p.Y;
19 }
20 result.XMax = xmax + xmax - xmin;
21 result.XMin = xmin - xmax + xmin;
22 result.YMax = ymax + ymax - ymin;
23 result.YMin = ymin - ymax + ymin;
24
25 return result;
26 }
========
