在C#中使用GDAL创建Shape文件
这几天在项目中考虑使用GDAL,由于10年没有用过VC了,就在网上搜了下怎么样在C# 中使用GDAL,看到了http://blog.csdn.net/liminlu0314/article/details/8828940这边文章。拿过来测试了一下,可以用,把自己的测试代码贴上来,以便日后参考。
// 为了支持中文路径,请添加下面这句代码 OSGeo.GDAL.Gdal.SetConfigOption("GDAL_FILENAME_IS_UTF8", "NO"); // 为了使属性表字段支持中文,请添加下面这句 OSGeo.GDAL.Gdal.SetConfigOption("SHAPE_ENCODING", ""); string strVectorFile = "E:\\TestPolygon.shp"; // 注册所有的驱动 Ogr.RegisterAll(); //创建数据,这里以创建ESRI的shp文件为例 string strDriverName = "ESRI Shapefile"; int count = Ogr.GetDriverCount(); Driver oDriver = Ogr.GetDriverByName(strDriverName); if (oDriver == null) { Console.WriteLine("%s 驱动不可用!\n", strVectorFile); return; } // 创建数据源 DataSource oDS = oDriver.CreateDataSource(strVectorFile, null); if (oDS == null) { Console.WriteLine("创建矢量文件【%s】失败!\n", strVectorFile); return; } // 创建图层,创建一个多边形图层,这里没有指定空间参考,如果需要的话,需要在这里进行指定 Layer oLayer = oDS.CreateLayer("TestPolygon", null, wkbGeometryType.wkbPolygon, null); if (oLayer == null) { Console.WriteLine("图层创建失败!\n"); return; } // 下面创建属性表 // 先创建一个叫FieldID的整型属性 FieldDefn oFieldID = new FieldDefn("FieldID", FieldType.OFTInteger); oLayer.CreateField(oFieldID, 1); // 再创建一个叫FeatureName的字符型属性,字符长度为50 FieldDefn oFieldName = new FieldDefn("FieldName", FieldType.OFTString); oFieldName.SetWidth(100); oLayer.CreateField(oFieldName, 1); FeatureDefn oDefn = oLayer.GetLayerDefn(); // 创建三角形要素 Feature oFeatureTriangle = new Feature(oDefn); oFeatureTriangle.SetField(0, 0); oFeatureTriangle.SetField(1, "三角形"); Geometry geomTriangle = Geometry.CreateFromWkt("POLYGON ((0 0,20 0,10 15,0 0))"); oFeatureTriangle.SetGeometry(geomTriangle); oLayer.CreateFeature(oFeatureTriangle); // 创建矩形要素 Feature oFeatureRectangle = new Feature(oDefn); oFeatureRectangle.SetField(0, 1); oFeatureRectangle.SetField(1, "矩形"); Geometry geomRectangle = Geometry.CreateFromWkt("POLYGON ((30 0,60 0,60 30,30 30,30 0))"); oFeatureRectangle.SetGeometry(geomRectangle); oLayer.CreateFeature(oFeatureRectangle); // 创建岛要素 Feature oFeatureHole= new Feature(oDefn); oFeatureHole.SetField(0, 1); oFeatureHole.SetField(1, "环岛测试"); //Geometry geomWYX = Geometry.CreateFromWkt("POLYGON ((30 0,60 0,60 30,30 30,30 0))"); OSGeo.OGR.Geometry outGeo = new OSGeo.OGR.Geometry(OSGeo.OGR.wkbGeometryType.wkbLinearRing); outGeo.AddPoint(40, -30, 0); outGeo.AddPoint(60, -30, 0); outGeo.AddPoint(60, -10, 0); outGeo.AddPoint(40, -10, 0); OSGeo.OGR.Geometry inGeo = new OSGeo.OGR.Geometry(OSGeo.OGR.wkbGeometryType.wkbLinearRing); inGeo.AddPoint(45, -25, 0); inGeo.AddPoint(55, -25, 0); inGeo.AddPoint(55, -15, 0); inGeo.AddPoint(45, -15, 0); OSGeo.OGR.Geometry geo = new OSGeo.OGR.Geometry(OSGeo.OGR.wkbGeometryType.wkbPolygon); geo.AddGeometryDirectly(outGeo); geo.AddGeometryDirectly(inGeo); oFeatureHole.SetGeometry(geo); oLayer.CreateFeature(oFeatureHole); // 创建Multi要素 Feature oFeatureMulty = new Feature(oDefn); oFeatureMulty.SetField(0, 1); oFeatureMulty.SetField(1, "MultyPart测试"); OSGeo.OGR.Geometry geo1 = new OSGeo.OGR.Geometry(OSGeo.OGR.wkbGeometryType.wkbLinearRing); geo1.AddPoint(25, -10, 0); geo1.AddPoint(5, -10, 0); geo1.AddPoint(5, -30, 0); geo1.AddPoint(25, -30, 0); OSGeo.OGR.Geometry poly1 = new Geometry(wkbGeometryType.wkbPolygon); poly1.AddGeometryDirectly(geo1); OSGeo.OGR.Geometry geo2 = new OSGeo.OGR.Geometry(OSGeo.OGR.wkbGeometryType.wkbLinearRing); geo2.AddPoint(0, -15, 0); geo2.AddPoint(-5, -15, 0); geo2.AddPoint(-5, -20, 0); geo2.AddPoint(0, -20, 0); OSGeo.OGR.Geometry poly2 = new Geometry(wkbGeometryType.wkbPolygon); poly2.AddGeometryDirectly(geo2); OSGeo.OGR.Geometry geoMulty = new OSGeo.OGR.Geometry(OSGeo.OGR.wkbGeometryType.wkbMultiPolygon); geoMulty.AddGeometryDirectly(poly1); geoMulty.AddGeometryDirectly(poly2); oFeatureMulty.SetGeometry(geoMulty); oLayer.CreateFeature(oFeatureMulty); ); Console.WriteLine("\n数据集创建完成!\n"); }
特别说明:
在GDAL中,MultiPolygon由多个Polygon组成;而Polygon由LinearRing组成,像环要素就是有一个外部LinearRing和若干个内部LinearRing组成的。