• C#读写Shapefile


    Shapefile文件是ArcGIS存储矢量要素的标准格式,要读写Shapefile最简单的方法当然是基于ArcObject(或者ArcEngine)开发,不过网上也有一些开源的解译Shapefile的代码都是值得参考的,lz曾经用到过一个,源码已经贴到下边,有兴趣的可以下载看看(来源已经记不清了,如果这是您的代码请联系我),下边是两种方法的代码,其实代码很简单,但由于经常会用到所以记下来以便日后查阅。直接上代码。

    打开Shapefile:

            public static IFeatureClass GetShpFile(string filePath, string fileName)
            {
                IFeatureWorkspace featureWorkspace;
                IFeatureClass featureClass;
    
                featureWorkspace = GetShapeWorkspace(filePath) as IFeatureWorkspace;
    
                try
                {
                    featureClass = featureWorkspace.OpenFeatureClass(fileName);
                }
                catch
                {
                    featureClass = null;
                }
    
                System.Runtime.InteropServices.Marshal.ReleaseComObject(featureWorkspace);
    
                return featureClass;
            }
            public static IWorkspace GetShapeWorkspace(string filePath)
            {
                IWorkspace workspace;
    
                IWorkspaceFactory workspaceFactory = new ShapefileWorkspaceFactoryClass();
    
                workspace = workspaceFactory.OpenFromFile(filePath, 0);
    
                System.Runtime.InteropServices.Marshal.ReleaseComObject(workspaceFactory);
                workspaceFactory = null;
    
                return workspace;
            }

    向Shapefile中添加要素(一点元素为例):

            public bool AddPointsToLayer(ILayer pLayer, List<IPoint> listPoint)
            {
                IFeatureLayer pFeatureLayer = pLayer as IFeatureLayer;
                if (pFeatureLayer == null)
                {
                    System.Windows.Forms.MessageBox.Show(pLayer.Name + "不是矢量图层!"); 
                    return false;
                }
               
                IFeatureClass pFeatureClass = pFeatureLayer.FeatureClass;
                if (pFeatureClass.ShapeType != esriGeometryType.esriGeometryPoint)
                {
                    System.Windows.Forms.MessageBox.Show(pLayer.Name + "不是点图层!"); 
                    return false;
                }
                
                IFeatureCursor pFeatureCursor = pFeatureClass.Insert(true);
                IFeatureBuffer pFeatureBuffer = null;
                foreach (var p in listPoint)
                {
                    pFeatureBuffer = pFeatureClass.CreateFeatureBuffer();
                    IFeature pNewFeature = pFeatureBuffer as IFeature;
                    pNewFeature.Shape = p as IGeometry;
    
                    pNewFeature.set_Value(pNewFeature.Fields.FindField("Name"), "point1");
                    //pNewFeature.Store();  
    
                    pFeatureCursor.InsertFeature(pFeatureBuffer);
                }
                pFeatureCursor.Flush();
    
                return true;
            }

     读取Shapefile的开源代码点击这里下载,下边是读取代码:

            private void openShapeFile()
            {
                //Create the dialog allowing the user to select the "*.shp" and the "*.dbf" files
                OpenFileDialog ofd = new OpenFileDialog();
                ofd.Multiselect = true;
    
                if (!(ofd.ShowDialog() ?? false))
                    return;
    
                //Get the file info objects for the SHP and the DBF file selected by the user
                FileInfo shapeFile = null;
                FileInfo dbfFile = null;
                foreach (FileInfo fi in ofd.Files)
                {
                    if (fi.Extension.ToLower() == ".shp")
                    {
                        shapeFile = fi;
                    }
                    if (fi.Extension.ToLower() == ".dbf")
                    {
                        dbfFile = fi;
                    }
                }
    
                //Read the SHP and DBF files into the ShapeFileReader
                ShapeFile shapeFileReader = new ShapeFile();
                if (shapeFile != null && dbfFile != null)
                {
                    shapeFileReader.Read(shapeFile, dbfFile);
                }
                else
                {
                    HtmlPage.Window.Alert("Please select a SP and a DBF file to proceed.");
                    return;
                }
    
                //Add the shapes from the shapefile into a graphics layer named "shapefileGraphicsLayer"
                //the greaphics layer should be present in the XAML or created earlier
                GraphicsLayer graphicsLayer = MyMap.Layers["shapefileGraphicsLayer"] as GraphicsLayer;
                foreach (ShapeFileRecord record in shapeFileReader.Records)
                {
                    Graphic graphic = record.ToGraphic();
                    if (graphic != null)
                        graphicsLayer.Graphics.Add(graphic);
                }
            }

    直接拖拽打开:

            private void MyMap_Drop(object sender, DragEventArgs e)
            {
                try
                {
                    //获取拖放到地图上的文件信息  
                    IDataObject dataObject = e.Data as IDataObject;
                    FileInfo[] files = dataObject.GetData(DataFormats.FileDrop) as FileInfo[];
    
                    //判断拖放的文件是否为.shp和.dbf  
                    FileInfo shapeFile = null;
                    FileInfo dbfFile = null;
                    foreach (FileInfo fi in files)
                    {
                        if (fi.Extension.ToLower() == ".shp") shapeFile = fi;
                        if (fi.Extension.ToLower() == ".dbf") dbfFile = fi;
                    }
    
                    // 读取Shapefile数据   
                    ShapeFile shapeFileReader = new ShapeFile();
                    if (shapeFile != null && dbfFile != null)
                    {
                        shapeFileReader.Read(shapeFile, dbfFile);
                    }
                    else
                    {
                        MessageBox.Show("请将.dbf和.shp文件同时拖放到地图上!");
                        return;
                    }
    
                    IList<Graphic> lstGraphics = new List<Graphic>();
                    foreach (ShapeFileRecord record in shapeFileReader.Records)
                    {
                        //将从Shapefile中读取的记录转换为Graphic  
                        Graphic graphic = record.ToGraphic();
    
                        //若没有空间参考将会报错,默认设置为地图参考
                        if (graphic.Geometry.SpatialReference == null)
                            graphic.Geometry.SpatialReference = MyMap.SpatialReference;
    
                        if (graphic != null) lstGraphics.Add(graphic);
                    }
    
                    // 如果空间参考不一致,可能需要投影  
                    if (lstGraphics.Count > 0)
                    {
                        GeometryService projectTask = new GeometryService("http://tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
                        projectTask.ProjectCompleted += new EventHandler<GraphicsEventArgs>(projectTask_ProjectCompleted);
                        projectTask.Failed += new EventHandler<TaskFailedEventArgs>(projectTask_Failed);
    
                        //将平面坐标转换为经纬度  
                        projectTask.ProjectAsync(lstGraphics, MyMap.SpatialReference);
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show("拖放文件错误:" + ex.ToString());
                }  
            }
  • 相关阅读:
    asp.net cookie的操作,写入、读取与操作
    JS控制表格隔行变色
    JS创建select的optgroup
    sitemap文件写法详解及参数说明
    IIS7 URL Rewrite Module Configuration Reference
    Asp.net 中文件的下载
    Context的一些简单运用
    QQ web api
    div下图片自适应解决方法
    C#中文分词算法:ChineseAnalyzer
  • 原文地址:https://www.cnblogs.com/Ghunter/p/4239771.html
Copyright © 2020-2023  润新知