using OSGeo.GDAL; using OSGeo.OGR; using OSGeo.OSR; using System; using System.Collections.Generic; using System.Diagnostics; using System.IO; using System.Linq; using System.Threading.Tasks; using System.Windows; using System.Windows.Markup; namespace DataLoader.CS { public class GdalHelper { #region 成员变量+构造函数+初始化 private static bool isInited = false; private static GdalHelper instance = null; private static readonly object obj = new object(); public static SpatialReference sr4326 = null; public static SpatialReference sr104903 = null; public static string MOON200 = "GCS_Moon_2000"; private GdalHelper() { lock (obj) { if (!isInited) { RegisterGDal(); sr4326 = new SpatialReference(null); sr4326.ImportFromEPSG(4326); string wkt = "GEOGCS[\"GCS_Moon_2000\",\r\n" + " DATUM[\"D_Moon_2000\",\r\n" + " SPHEROID[\"Moon_2000_IAU_IAG\",1737400,0,\r\n" + " AUTHORITY[\"ESRI\",\"107903\"]],\r\n" + " AUTHORITY[\"ESRI\",\"106903\"]],\r\n" + " PRIMEM[\"Reference_Meridian\",0,\r\n" + " AUTHORITY[\"ESRI\",\"108900\"]],\r\n" + " UNIT[\"degree\",0.0174532925199433,\r\n" + " AUTHORITY[\"EPSG\",\"9122\"]],\r\n" + " AUTHORITY[\"ESRI\",\"104903\"]]"; sr104903 = new SpatialReference(wkt); //sr104903.ImportFromWkt(ref wkt); isInited = true; } } } public static GdalHelper Instance { get { lock (obj) { if (null == instance) instance = new GdalHelper(); return instance; } } } public void RegisterGDal() { string gdalData = Path.Combine(StaticData.BasePath, "gdal-data"); Environment.SetEnvironmentVariable("GDAL_DATA", gdalData); string proj7 = Path.Combine(StaticData.BasePath, "proj7\\share"); Environment.SetEnvironmentVariable("PROJ_LIB", proj7); Gdal.SetConfigOption("GDAL_FILENAME_IS_UTF8", "YES"); // NO,YES Gdal.SetConfigOption("SHAPE_ENCODING", ""); // 空,gb2312,CP936 Ogr.RegisterAll(); Gdal.AllRegister(); } #endregion public void ReadTiff() { string outPath = "D:\\xyz\\ce\\xyz"; string tif = "D:\\Moon\\data\\dom_tif\\moon.tif"; Dataset ds = Gdal.Open(tif, Access.GA_ReadOnly); int x = ds.RasterXSize; int y = ds.RasterYSize; SpatialReference sr = ds.GetSpatialRef(); string srName = sr.GetName(); // GCS_Moon_2000 // string code = sr4326.GetAuthorityCode(null); // 4326 if (MOON200 != srName) return; double[] lt = ImageToGeoSpace(ds, 0, 0); // -179.99998351102391, 89.999983511056882 double[] rb = ImageToGeoSpace(ds, x, y); // 179.999788852709, -89.9999026708093 string polygon = string.Format("", ""); } // 从地理空间转换到像素空间 private int[] Geo2ImageSpace(Dataset ds, double x, double y) { double[] transform = new double[6]; ds.GetGeoTransform(transform); // 影像坐标变换参数 int col = (int)((y * transform[1] - x * transform[4] + transform[0] * transform[4] - transform[3] * transform[1]) / (transform[5] * transform[1] - transform[2] * transform[4])); // 像素所在列 int row = (int)((x - transform[0] - col * transform[2]) / transform[1]); // 像素所在行 return new int[] { row, col }; } // 从地理空间转换到像素空间 private int[] Geo2ImageSpace(double[] transform, double x, double y) { int col = (int)((y * transform[1] - x * transform[4] + transform[0] * transform[4] - transform[3] * transform[1]) / (transform[5] * transform[1] - transform[2] * transform[4])); // 像素所在列 int row = (int)((x - transform[0] - col * transform[2]) / transform[1]); // 像素所在行 return new int[] { row, col }; } // 从像素空间转换到地理空间 private double[] ImageToGeoSpace(Dataset ds, int row, int col) { double[] transform = new double[6]; ds.GetGeoTransform(transform); double x = transform[0] + row * transform[1] + col * transform[2]; double y = transform[3] + row * transform[4] + col * transform[5]; return new double[] { x, y }; } #region GDAL切图 private Geometry GetMinPoint(Dataset ds) { double[] transform = new double[6]; ds.GetGeoTransform(transform); string epsg = ds.GetSpatialRef().GetAuthorityCode(null); double xMin = transform[0]; double yMin = transform[3]; Geometry point = new Geometry(wkbGeometryType.wkbPoint); point.AddPoint(xMin, yMin, 0); if ("4326" == epsg) { point.AssignSpatialReference(sr4326); return point; } point.AssignSpatialReference(ds.GetSpatialRef()); point.TransformTo(sr4326); return point; } private Geometry GetMaxPoint(Dataset ds) { double[] transform = new double[6]; ds.GetGeoTransform(transform); string epsg = ds.GetSpatialRef().GetAuthorityCode(null); double xMax = transform[0] + (ds.RasterXSize * transform[1]); double yMax = transform[3] + (ds.RasterYSize * transform[1]); Geometry point = new Geometry(wkbGeometryType.wkbPoint); point.AddPoint(xMax, yMax, 0); if ("4326" == epsg) { point.AssignSpatialReference(sr4326); return point; } point.AssignSpatialReference(ds.GetSpatialRef()); point.TransformTo(sr4326); return point; } public void GenerateTiles() { string outPath = "D:\\xyz\\ce\\xyz2"; string file = "D:\\xyz\\ce\\5_A1.tif"; if (!File.Exists(file)) return; Stopwatch sw = new Stopwatch(); sw.Start(); // 程序开始时间 Dataset ds = null; try { ds = Gdal.Open(file, Access.GA_Update); if (null == ds) return; double[] transform = new double[6]; ds.GetGeoTransform(transform); int rasterCount = ds.RasterCount; Console.WriteLine(string.Format("Origin = ({0}, {1})", transform[0], transform[3])); Console.WriteLine(string.Format("Pixel Size = ({0}, {1})", transform[1], transform[5])); // 4.1 首先获取原始影像的地理坐标范围 Geometry minPoint = GetMinPoint(ds); Geometry maxPoint = GetMaxPoint(ds); double xmin = minPoint.GetX(0); double ymin = minPoint.GetY(0); double xmax = maxPoint.GetX(0); double ymax = maxPoint.GetY(0); Geometry imageBound = CreatePolygon(xmin, xmax, ymin, ymax, sr4326); // 4.2 获取原始影像的像素分辨率 // 原始图像东西方向像素分辨率 double src_w_e_pixel_resolution = (xmax - xmin) / ds.RasterXSize; // 原始图像南北方向像素分辨率 double src_n_s_pixel_resolution = (ymax - ymin) / ds.RasterYSize; // 获取Band Band in_band1 = ds.GetRasterBand(1); Band in_band2 = ds.GetRasterBand(2); Band in_band3 = ds.GetRasterBand(3); //in_band1.Fill(0, 255); // GdalConst.GMF_NODATA in_band1.SetNoDataValue(0); // -9999 in_band2.SetNoDataValue(0); in_band3.SetNoDataValue(0); int BufferSize = 256 * 256 * 5; // GdalConst.GDT_Int32 for (int zoom = 10; zoom <= 18; zoom++) { // 4.3 根据原始影像地理范围求解切片行列号 // 经纬度转瓦片编号 int tileRowMax = Lat2tile(ymin, zoom); // 纬度 -90 -> 90 lat int tileRowMin = Lat2tile(ymax, zoom); int tileColMin = Lon2tile(xmin, zoom); // 经度 -180 -> 180 lon int tileColMax = Lon2tile(xmax, zoom); Parallel.For(tileColMin, tileColMax + 1, (col) => { Parallel.For(tileRowMin, tileRowMax + 1, (row) => { // 4.4 求原始影像地理范围与指定缩放级别指定行列号的切片交集 double tempLatMin = Tile2lat(row + 1, zoom); double tempLatMax = Tile2lat(row, zoom); double tempLonMin = Tile2lon(col, zoom); double tempLonMax = Tile2lon(col + 1, zoom); Console.WriteLine(string.Format("{0}\\{1}\\{2}.png", zoom, col, row)); Geometry tileBound = CreatePolygon(tempLonMin, tempLonMax, tempLatMin, tempLatMax, sr4326); Geometry intersect = tileBound.Intersection(imageBound); if (null == intersect) { Console.WriteLine(string.Format("{0}\\{1}\\{2}.png,不存在", zoom, col, row)); return; } Envelope env = new Envelope(); intersect.GetEnvelope(env); // 4.5 求解当前切片的像素分辨率(默认切片大小为256*256) // 切片东西方向像素分辨率 double dst_w_e_pixel_resolution = (tempLonMax - tempLonMin) / 256; // 切片南北方向像素分辨率 double dst_n_s_pixel_resolution = (tempLatMax - tempLatMin) / 256; // 4.6 计算交集的像素信息 // 求切图范围和原始图像交集的起始点像素坐标 int offset_x = (int)((env.MinX - xmin) / src_w_e_pixel_resolution); int offset_y = (int)Math.Abs((env.MaxY - ymax) / src_n_s_pixel_resolution); // 求在切图地理范围内的原始图像的像素大小 int block_xsize = (int)((env.MaxX - env.MinX) / src_w_e_pixel_resolution); int block_ysize = (int)((env.MaxY - env.MinY) / src_n_s_pixel_resolution); // 求原始图像在切片内的像素大小 int image_Xbuf = (int)Math.Ceiling((env.MaxX - env.MinX) / dst_w_e_pixel_resolution); int image_Ybuf = (int)Math.Ceiling(Math.Abs((env.MaxY - env.MinY) / dst_n_s_pixel_resolution)); // 求原始图像在切片中的偏移坐标 int imageOffsetX = (int)((env.MinX - tempLonMin) / dst_w_e_pixel_resolution); int imageOffsetY = (int)Math.Abs((env.MaxY - tempLatMax) / dst_n_s_pixel_resolution); imageOffsetX = imageOffsetX > 0 ? imageOffsetX : 0; imageOffsetY = imageOffsetY > 0 ? imageOffsetY : 0; // 4.7 使用GDAL的ReadRaster方法对影像指定范围进行读取与压缩。 // 推荐在切片前建立原始影像的金字塔文件,ReadRaster在内部实现中可直接读取相应级别的金字塔文件,提高效率。 int[] band1BuffData = new int[BufferSize]; // 256 * 256 * GdalConst.GDT_Int32 int[] band2BuffData = new int[BufferSize]; int[] band3BuffData = new int[BufferSize]; try { in_band1.ReadRaster(offset_x, offset_y, block_xsize, block_ysize, band1BuffData, image_Xbuf, image_Ybuf, 0, 0); in_band2.ReadRaster(offset_x, offset_y, block_xsize, block_ysize, band2BuffData, image_Xbuf, image_Ybuf, 0, 0); in_band3.ReadRaster(offset_x, offset_y, block_xsize, block_ysize, band3BuffData, image_Xbuf, image_Ybuf, 0, 0); // 4.8 将切片数据写入文件 // 使用gdal的MEM驱动在内存中创建一块区域存储图像数组 OSGeo.GDAL.Driver memDriver = Gdal.GetDriverByName("MEM"); Dataset msmDS = memDriver.Create("msmDS", 256, 256, 4, DataType.GDT_Int32, null); Band dstBand1 = msmDS.GetRasterBand(1); Band dstBand2 = msmDS.GetRasterBand(2); Band dstBand3 = msmDS.GetRasterBand(3); // 设置alpha波段数据,实现背景透明 Band alphaBand = msmDS.GetRasterBand(4); int[] alphaData = new int[BufferSize]; for (int index = 0; index < alphaData.Length; index++) { if (band1BuffData[index] > 0) alphaData[index] = 255; } // 写各个波段数据 dstBand1.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, band1BuffData, image_Xbuf, image_Ybuf, 0, 0); dstBand2.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, band2BuffData, image_Xbuf, image_Ybuf, 0, 0); dstBand3.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, band3BuffData, image_Xbuf, image_Ybuf, 0, 0); alphaBand.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, alphaData, image_Xbuf, image_Ybuf, 0, 0); string path = Path.Combine(outPath, zoom.ToString(), col.ToString()); if (!Directory.Exists(path)) Directory.CreateDirectory(path); // 使用PNG驱动将内存中的图像数组写入文件 string pngPath = path + "\\" + row + ".png"; OSGeo.GDAL.Driver pngDriver = Gdal.GetDriverByName("PNG"); Dataset pngDs = pngDriver.CreateCopy(pngPath, msmDS, 0, null, null, null); msmDS.FlushCache(); pngDs.Dispose(); // 释放内存 } catch (Exception ex) { Console.WriteLine(ex.Message); } }); }); } } catch (Exception ex) { Console.WriteLine(ex.Message); } finally { if (null != ds) ds.Dispose(); sw.Stop(); // 程序结束 Console.WriteLine("耗时" + Math.Round(sw.ElapsedMilliseconds / 1000.0, 2) + "s"); // 秒 } } public void GenerateTiles2() { string outPath = "D:\\xyz\\ce\\xyz"; string file = "D:\\xyz\\ce\\5_A1.tif"; //string file = "d:\\xyz\\dem\\dem\\33b.tif"; //string file = "D:\\xyz\\dq\\dq.vrt"; if (!File.Exists(file)) return; Stopwatch sw = new Stopwatch(); sw.Start(); // 程序开始时间 Dataset ds = null; try { ds = Gdal.Open(file, Access.GA_Update); if (null == ds) return; double[] transform = new double[6]; ds.GetGeoTransform(transform); int rasterCount = ds.RasterCount; Console.WriteLine(string.Format("Origin = ({0}, {1})", transform[0], transform[3])); Console.WriteLine(string.Format("Pixel Size = ({0}, {1})", transform[1], transform[5])); // 4.1 首先获取原始影像的地理坐标范围 Geometry minPoint = GetMinPoint(ds); Geometry maxPoint = GetMaxPoint(ds); double xmin = minPoint.GetX(0); double ymin = minPoint.GetY(0); double xmax = maxPoint.GetX(0); double ymax = maxPoint.GetY(0); Geometry imageBound = CreatePolygon(xmin, xmax, ymin, ymax, sr4326); // 4.2 获取原始影像的像素分辨率 // 原始图像东西方向像素分辨率 double src_w_e_pixel_resolution = (xmax - xmin) / ds.RasterXSize; // 原始图像南北方向像素分辨率 double src_n_s_pixel_resolution = (ymax - ymin) / ds.RasterYSize; // 获取Band Band in_band1 = ds.GetRasterBand(1); Band in_band2 = ds.GetRasterBand(2); Band in_band3 = ds.GetRasterBand(3); //in_band1.Fill(0, 255); // GdalConst.GMF_NODATA in_band1.SetNoDataValue(0); // -9999 in_band2.SetNoDataValue(0); in_band3.SetNoDataValue(0); int BufferSize = 256 * 256 * 5; // GdalConst.GDT_Int32 for (int zoom = 10; zoom <= 18; zoom++) { // 4.3 根据原始影像地理范围求解切片行列号 // 经纬度转瓦片编号 int tileRowMax = Lat2tile(ymin, zoom); // 纬度 -90 -> 90 lat int tileRowMin = Lat2tile(ymax, zoom); int tileColMin = Lon2tile(xmin, zoom); // 经度 -180 -> 180 lon int tileColMax = Lon2tile(xmax, zoom); //int tileRowMax = lat2tile(latMin, zoom); // 纬度 -90 ——90 lat //int tileRowMin = lat2tile(latMax, zoom); // 经度 -180 -- 180 lon //int tileColMin = lon2tile(lonMin, zoom); //int tileColMax = lon2tile(lonMax, zoom); for (int col = tileColMin; col <= tileColMax; col++) { for (int row = tileRowMin; row <= tileRowMax; row++) { // 4.4 求原始影像地理范围与指定缩放级别指定行列号的切片交集 double tempLatMin = Tile2lat(row + 1, zoom); double tempLatMax = Tile2lat(row, zoom); double tempLonMin = Tile2lon(col, zoom); double tempLonMax = Tile2lon(col + 1, zoom); //double tempLatMin = tile2lat(row + 1, zoom); //double tempLatMax = tile2lat(row, zoom); //double tempLonMin = tile2lon(col, zoom); //double tempLonMax = tile2lon(col + 1, zoom); Console.WriteLine(string.Format("{0}\\{1}\\{2}.png", zoom, col, row)); Geometry tileBound = CreatePolygon(tempLonMin, tempLonMax, tempLatMin, tempLatMax, sr4326); Geometry intersect = tileBound.Intersection(imageBound); if (null == intersect) { Console.WriteLine(string.Format("{0}\\{1}\\{2}.png,不存在", zoom, col, row)); continue; } Envelope env = new Envelope(); intersect.GetEnvelope(env); // 4.5 求解当前切片的像素分辨率(默认切片大小为256*256) // 切片东西方向像素分辨率 double dst_w_e_pixel_resolution = (tempLonMax - tempLonMin) / 256; // 切片南北方向像素分辨率 double dst_n_s_pixel_resolution = (tempLatMax - tempLatMin) / 256; // 4.6 计算交集的像素信息 // 求切图范围和原始图像交集的起始点像素坐标 int offset_x = (int)((env.MinX - xmin) / src_w_e_pixel_resolution); int offset_y = (int)Math.Abs((env.MaxY - ymax) / src_n_s_pixel_resolution); // 求在切图地理范围内的原始图像的像素大小 int block_xsize = (int)((env.MaxX - env.MinX) / src_w_e_pixel_resolution); int block_ysize = (int)((env.MaxY - env.MinY) / src_n_s_pixel_resolution); // 求原始图像在切片内的像素大小 int image_Xbuf = (int)Math.Ceiling((env.MaxX - env.MinX) / dst_w_e_pixel_resolution); int image_Ybuf = (int)Math.Ceiling(Math.Abs((env.MaxY - env.MinY) / dst_n_s_pixel_resolution)); // 求原始图像在切片中的偏移坐标 int imageOffsetX = (int)((env.MinX - tempLonMin) / dst_w_e_pixel_resolution); int imageOffsetY = (int)Math.Abs((env.MaxY - tempLatMax) / dst_n_s_pixel_resolution); imageOffsetX = imageOffsetX > 0 ? imageOffsetX : 0; imageOffsetY = imageOffsetY > 0 ? imageOffsetY : 0; // 4.7 使用GDAL的ReadRaster方法对影像指定范围进行读取与压缩。 // 推荐在切片前建立原始影像的金字塔文件,ReadRaster在内部实现中可直接读取相应级别的金字塔文件,提高效率。 int[] band1BuffData = new int[BufferSize]; // 256 * 256 * GdalConst.GDT_Int32 int[] band2BuffData = new int[BufferSize]; int[] band3BuffData = new int[BufferSize]; try { // ReadRaster(int xOff, int yOff, int xSize, int ySize, int[] buffer, int buf_xSize, int buf_ySize, int pixelSpace, int lineSpace) //in_band1.ReadRaster(offset_x, offset_y, block_xsize, block_ysize, image_Xbuf, image_Ybuf, GdalConst.GDT_Int32, band1BuffData, 0, 0); //in_band2.ReadRaster(offset_x, offset_y, block_xsize, block_ysize, image_Xbuf, image_Ybuf, GdalConst.GDT_Int32, band2BuffData, 0, 0); //in_band3.ReadRaster(offset_x, offset_y, block_xsize, block_ysize, image_Xbuf, image_Ybuf, GdalConst.GDT_Int32, band3BuffData, 0, 0); in_band1.ReadRaster(offset_x, offset_y, block_xsize, block_ysize, band1BuffData, image_Xbuf, image_Ybuf, 0, 0); in_band2.ReadRaster(offset_x, offset_y, block_xsize, block_ysize, band2BuffData, image_Xbuf, image_Ybuf, 0, 0); in_band3.ReadRaster(offset_x, offset_y, block_xsize, block_ysize, band3BuffData, image_Xbuf, image_Ybuf, 0, 0); // 4.8 将切片数据写入文件 // 使用gdal的MEM驱动在内存中创建一块区域存储图像数组 OSGeo.GDAL.Driver memDriver = Gdal.GetDriverByName("MEM"); Dataset msmDS = memDriver.Create("msmDS", 256, 256, 4, DataType.GDT_Int32, null); Band dstBand1 = msmDS.GetRasterBand(1); Band dstBand2 = msmDS.GetRasterBand(2); Band dstBand3 = msmDS.GetRasterBand(3); // 设置alpha波段数据,实现背景透明 Band alphaBand = msmDS.GetRasterBand(4); int[] alphaData = new int[BufferSize]; for (int index = 0; index < alphaData.Length; index++) { if (band1BuffData[index] > 0) { alphaData[index] = 255; } } // 写各个波段数据 // WriteRaster(int xOff, int yOff, int xSize, int ySize, int[] buffer, int buf_xSize, int buf_ySize, int pixelSpace, int lineSpace) //dstBand1.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, band1BuffData); //dstBand2.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, band2BuffData); //dstBand3.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, band3BuffData); //alphaBand.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, alphaData); dstBand1.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, band1BuffData, image_Xbuf, image_Ybuf, 0, 0); dstBand2.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, band2BuffData, image_Xbuf, image_Ybuf, 0, 0); dstBand3.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, band3BuffData, image_Xbuf, image_Ybuf, 0, 0); alphaBand.WriteRaster(imageOffsetX, imageOffsetY, image_Xbuf, image_Ybuf, alphaData, image_Xbuf, image_Ybuf, 0, 0); //String pngPath = "D:\\xyz\\temp" + "\\" + zoom + "c" + col + "r" + row + ".png"; //Console.WriteLine("pngPath=" + pngPath); string path = Path.Combine(outPath, zoom.ToString(), col.ToString()); if (!Directory.Exists(path)) Directory.CreateDirectory(path); // 使用PNG驱动将内存中的图像数组写入文件 string pngPath = path + "\\" + row + ".png"; OSGeo.GDAL.Driver pngDriver = Gdal.GetDriverByName("PNG"); Dataset pngDs = pngDriver.CreateCopy(pngPath, msmDS, 0, null, null, null); // 释放内存 msmDS.FlushCache(); pngDs.Dispose(); } catch (Exception ex) { Console.WriteLine(ex.Message); } } } } } catch (Exception ex) { Console.WriteLine(ex.Message); } finally { if (null != ds) ds.Dispose(); sw.Stop(); // 程序结束 Console.WriteLine("耗时" + Math.Round(sw.ElapsedMilliseconds / 1000.0, 2) + "s"); // 秒 } } /// /// 创建多边形 /// public Geometry CreatePolygon(double xmin, double xmax, double ymin, double ymax, SpatialReference sr) { string kwt = string.Format("POLYGON (({0} {1},{2} {3},{4} {5},{6} {7},{0} {1}))", xmin, ymax, xmax, ymax, xmax, ymin, xmin, ymin); Geometry geo = Geometry.CreateFromWkt(kwt); geo.AssignSpatialReference(sr); return geo; } /// /// 经度转瓦片编号 /// public static int Lon2tile(double lon, int zoom) { return (int)(Math.Floor((lon + 180) / 360 * Math.Pow(2, zoom))); } /// /// 纬度转瓦片编号 /// public static int Lat2tile(double lat, int zoom) { return (int)(Math.Floor((1 - Math.Log(Math.Tan(lat * Math.PI / 180) + 1 / Math.Cos(lat * Math.PI / 180)) / Math.PI) / 2 * Math.Pow(2, zoom))); } /// /// 瓦片编号转经度 /// public static double Tile2lon(int col, int zoom) { return col / Math.Pow(2.0, zoom) * 360.0 - 180; } /// /// 瓦片编号转纬度 /// public static double Tile2lat(int row, int zoom) { double n = Math.PI - (2.0 * Math.PI * row) / Math.Pow(2.0, zoom); return ToDegrees(Math.Atan(Math.Sinh(n))); } /// /// 常数e /// public static readonly double E = 2.7182818284590452354; /// /// 常数Pi /// public static readonly double PI = 3.14159265358979323846; /// /// 度转弧度 /// public static double ToRadians(double angdeg) { return angdeg / 180.0 * Math.PI; } /// /// 弧度转度 /// public static double ToDegrees(double angrad) { return angrad * 180.0 / Math.PI; } #endregion } }