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打造地图拼接利器(三)图源配置

打造地图拼接利器(三)图源配置

作者: 安静的林哥 | 来源:发表于2021-06-27 00:39 被阅读0次

打造地图拼接利器(三)图源配置

GMap.net内置了74个地图图源,清单如下:

ArcGIS_DarbAE_Q2_2011_NAVTQ_Eng_V5_MapProvider ArcGIS_DarbAE_Q2_2011_NAVTQ_Eng_V5_Map;
  ArcGIS_Imagery_World_2D_MapProvider ArcGIS_Imagery_World_2D_Map;
  ArcGIS_ShadedRelief_World_2D_MapProvider ArcGIS_ShadedRelief_World_2D_Map;
  ArcGIS_StreetMap_World_2D_MapProvider ArcGIS_StreetMap_World_2D_Map;
  ArcGIS_Topo_US_2D_MapProvider ArcGIS_Topo_US_2D_Map;
  ArcGIS_World_Physical_MapProvider ArcGIS_World_Physical_Map;
  ArcGIS_World_Shaded_Relief_MapProvider ArcGIS_World_Shaded_Relief_Map;
  ArcGIS_World_Street_MapProvider ArcGIS_World_Street_Map;
  ArcGIS_World_Terrain_Base_MapProvider ArcGIS_World_Terrain_Base_Map;
  ArcGIS_World_Topo_MapProvider ArcGIS_World_Topo_Map;
  BingHybridMapProvider BingHybridMap;
  BingMapProvider BingMap;
  BingSatelliteMapProvider BingSatelliteMap;
  CloudMadeMapProvider CloudMadeMap;
  CzechGeographicMapProvider CzechGeographicMap;
  CzechHistoryMapProvider CzechHistoryMap;
  CzechHistoryMapProviderOld CzechHistoryOldMap;
  CzechHybridMapProvider CzechHybridMap;
  CzechHybridMapProviderOld CzechHybridOldMap;
  CzechMapProvider CzechMap;
  CzechMapProviderOld CzechOldMap;
  CzechSatelliteMapProvider CzechSatelliteMap;
  CzechSatelliteMapProviderOld CzechSatelliteOldMap;
  CzechTuristMapProvider CzechTuristMap;
  CzechTuristMapProviderOld CzechTuristOldMap;
  CzechTuristWinterMapProvider CzechTuristWinterMap;
  EmptyProvider EmptyProvider;
  GoogleChinaHybridMapProvider GoogleChinaHybridMap;
  GoogleChinaMapProvider GoogleChinaMap;
  GoogleChinaSatelliteMapProvider GoogleChinaSatelliteMap;
  GoogleChinaTerrainMapProvider GoogleChinaTerrainMap;
  GoogleHybridMapProvider GoogleHybridMap;
  GoogleKoreaHybridMapProvider GoogleKoreaHybridMap;
  GoogleKoreaMapProvider GoogleKoreaMap;
  GoogleKoreaSatelliteMapProvider GoogleKoreaSatelliteMap;
  GoogleMapProvider GoogleMap;
  GoogleSatelliteMapProvider GoogleSatelliteMap;
  GoogleTerrainMapProvider GoogleTerrainMap;
  LatviaMapProvider LatviaMap;
  Lithuania3dMapProvider Lithuania3dMap;
  LithuaniaHybridMapProvider LithuaniaHybridMap;
  LithuaniaHybridOldMapProvider LithuaniaHybridOldMap;
  LithuaniaMapProvider LithuaniaMap;
  LithuaniaOrtoFotoMapProvider LithuaniaOrtoFotoMap;
  LithuaniaOrtoFotoOldMapProvider LithuaniaOrtoFotoOldMap;
  LithuaniaReliefMapProvider LithuaniaReliefMap;
  LithuaniaTOP50 LithuaniaTOP50Map;
  MapBenderWMSProvider MapBenderWMSdemoMap;
  NearHybridMapProvider NearHybridMap;
  NearMapProvider NearMap;
  NearSatelliteMapProvider NearSatelliteMap;
  OpenCycleLandscapeMapProvider OpenCycleLandscapeMap;
  OpenCycleMapProvider OpenCycleMap;
  OpenCycleTransportMapProvider OpenCycleTransportMap;
  OpenSeaMapHybridProvider OpenSeaMapHybrid;
  OpenStreet4UMapProvider OpenStreet4UMap;
  OpenStreetMapProvider OpenStreetMap;
  OpenStreetMapQuestProvider OpenStreetMapQuest;
  OpenStreetMapQuestHybridProvider OpenStreetMapQuestHybrid;
  OpenStreetMapQuestSatteliteProvider OpenStreetMapQuestSattelite;
  OviHybridMapProvider OviHybridMap;
 OviMapProvider OviMap;
  OviSatelliteMapProvider OviSatelliteMap;
  OviTerrainMapProvider OviTerrainMap;
  SpainMapProvider SpainMap;
  SwedenMapProvider SwedenMap;
  TurkeyMapProvider TurkeyMap;
  WikiMapiaMapProvider WikiMapiaMap;
  YahooHybridMapProvider YahooHybridMap;
  YahooMapProvider YahooMap;
  YahooSatelliteMapProvider YahooSatelliteMap;
  YandexHybridMapProvider YandexHybridMap;
  YandexMapProvider YandexMap;
  YandexSatelliteMapProvider YandexSatelliteMap;

但在实际使用中,大部分都因一些未知因素而无法访问,特别是国外的地图,大部分对我国边境标绘错误,需谨慎使用。而且这些地图中,鲜有国内地图商的地址。

为便于使用国内地图,我们需要写一些访问国内地图数据的代码,还好,GMap.net开源,我们可以照猫画虎,写一个通用的TMSProvider。

在解决方案资源管理器中建一个文件夹,名为Utils。

要是用自定义Provider,首先建一个基类TmsProviderBase,让他继承自GMapProvider,并重写2个方法。

using GMap.NET;
using GMap.NET.MapProviders;
using GMap.NET.Projections;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Mapmeger
{
    public abstract class TmsProviderBase : GMapProvider
    {
        public TmsProviderBase()
        {
            MaxZoom = null;
            RefererUrl = "";
        }

        public override PureProjection Projection
        {
            get { return MercatorProjection.Instance; }
        }

        GMapProvider[] overlays;
        public override GMapProvider[] Overlays
        {
            get
            {
                if (overlays == null)
                {
                    overlays = new GMapProvider[] { this };
                }
                return overlays;
            }
        }
    }
}

然后新建一个类TmsProvider,继承自我们刚新建的类TmsProviderBase,重新其核心方法

public override PureImage GetTileImage(GPoint pos, int zoom){}

当我们使用自定义的地图源时,就会调用这个函数,传来瓦片坐标GPoint和层级,然后通过网络请求,返回瓦片图片对象。

GMap.net为我们提供了一个函数GetTileImageUsingHttp(string url),用以通过一个网络瓦片地址返回一个瓦片图片。

如何获得这个地址呢,我们以获取天地图瓦片地址为例。打开谷歌浏览器,输入https://www.tianditu.gov.cn/,按F12进入浏览器调试模式,选择Network选项卡,然后调整地图大小,可以看到图片请求地址:

3.1.png

拷贝其中一个,可以看到:

https://t3.tianditu.gov.cn/vec_w/wmts?SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=vec&STYLE=default&TILEMATRIXSET=w&FORMAT=tiles&TILECOL=11&TILEROW=5&TILEMATRIX=4&tk=9a02b3cdd29cd346de4df04229797710

其中,t3代表第3个服务器,TILECOL=11&TILEROW=5&TILEMATRIX=4代表x=11,y=5,z=4,最后还有一个密钥tk,如果没有这个tk,就无法访问到数据。密钥可以通过注册天地图开发者账号申请,但普通开发者每天只能访问10000次数据,公司和政府机构会比较多,分别为300w和500w。

在实际使用过程中,内置GetTileImageUsingHttp(string url)函数并不能获取到所有网站的数据,因为地图服务端认为客户端不是浏览器,所以我们要重新一个请求程序,在http请求头中加入“我是浏览器”的声明,才可以获取到数据。

我们新建一个Tools类,再新建一个下载图片的函数:

   public static byte[] downloadTile(string url)
        {
            try
            {
                WebClient myClient = new WebClient();
                myClient.Headers.Add( "User-Agent","Mozilla/5.0(Windows NT 6.1;Win64; x64; rv:50.0) Gecko/20100101 Firefox/50.0");
                myClient.Encoding = Encoding.UTF8;
                Uri uri = new Uri(url);
                byte[] bts = myClient.DownloadData(uri);
                return bts;
            }
            catch (Exception err)
            {
                return null;
            }
        }

同时,为了提高程序复用性,我们通过一个地址就可以自动生成一个心得Provider,需要写一个地址解析函数,自动替换{x},{y},{z}和服务器地址,比如把https://a[1-4].tile.openstreetmap.org/{z}/{x}/{y}.png根据请求自动替换为https://a1.tile.openstreetmap.org/3/1/1.png


还有一个很重要的问题,就是图片合并的问题,有些卫星图是不带路网和地名的,需要将两个图形合并后返回。所以我们为TmsProvider提供一个参数,用以将1种图或2种图合并后返回给地图程序。

  public static string getUrl(string urlformat,int x,int y ,int z)
        {
            int leftSignPos = -1, rightSignPos = -1;
            leftSignPos = urlformat.IndexOf('[');
            rightSignPos = urlformat.IndexOf(']');
            if (leftSignPos > 0 && rightSignPos > leftSignPos)
            {
                string serverstr = urlformat.Substring(leftSignPos + 1, rightSignPos - leftSignPos - 1);
                int startnum = int.Parse(serverstr.Split('-')[0]);
                int endnum = int.Parse(serverstr.Split('-')[1]);
                long num = (x + y) % (endnum - startnum) + startnum;
                string nurl = urlformat.Substring(0, leftSignPos) + num + urlformat.Substring(rightSignPos + 1);
                urlformat = nurl;
            }
            urlformat = urlformat.Replace("{x}", x.ToString())
                .Replace("{y}", y.ToString())
                .Replace("{z}", z.ToString());
            return urlformat;
        }

图片返回函数如下:

 PureImage GetImgFromUrl(GPoint pos, int zoom, string url)
        {
            //return GetTileImageUsingHttp(MakeTileImageUrl(pos, zoom, url));
            string durl = MakeTileImageUrl(pos, zoom, url);
            byte[] bts = Tools.downloadTile(durl);
            MemoryStream ms = new MemoryStream();
            ms.Write(bts, 0, bts.Length);
            Image img = Bitmap.FromStream(ms);
            GMapImage gimg = new GMapImage();
            gimg.Data = ms;
            gimg.Img = img;
            ms.Dispose();
            return gimg;
        }

        PureImage GetMultiImgFromUrl(GPoint pos, int zoom, string url1, string url2)
        {
            GMapImage img = new GMapImage();
            string durl1 = MakeTileImageUrl(pos, zoom, url1);
            byte[] bts1 = Tools.downloadTile(durl1);
            string durl2 = MakeTileImageUrl(pos, zoom, url2);
            byte[] bts2 = Tools.downloadTile(durl2);

            MemoryStream ms1 = new MemoryStream();
            ms1.Write(bts1, 0, bts1.Length);
            Image img1 = Bitmap.FromStream(ms1);
            
            MemoryStream ms2 = new MemoryStream();
            ms2.Write(bts2, 0, bts2.Length);
            Image img2 = Bitmap.FromStream(ms2);

            Image bit = new Bitmap(256,256);
            Graphics g = Graphics.FromImage(bit);

            g.DrawImage(img1, 0, 0, img1.Width, img1.Height);
            g.DrawImage(img2, 0, 0, img2.Width, img2.Height);
            MemoryStream ms = new MemoryStream();
            bit.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
            img.Img = bit;
            img.Data = ms;
            g.Dispose();
            ms.Close();
            ms1.Dispose();
            ms2.Dispose();
            return img;
        }

在前端,我们通过一个配置文件config.txt,将能使用的图源地址进行配置:

//配置说明:竖线前为地图名称,后为TMS地址,方括号内为服务器序号,{x}\{y}\{z}分别代表瓦片坐标。很多地图都需要key授权,天地图的key可以自行申请,每天都会受到使用次数限制
openstreet交通|https://a.tile.openstreetmap.org/{z}/{x}/{y}.png
高德影像|https://webst0[1-4].is.autonavi.com/appmaptile?style=6&x={x}&y={y}&z={z}
高德矢量|http://wprd0[1-4].is.autonavi.com/appmaptile?lang=zh_cn&size=1&style=7&x={x}&y={y}&z={z}
高德注记|https://wprd0[1-4].is.autonavi.com/appmaptile?x={x}&y={y}&z={z}&lang=zh_cn&size=1&scl=1&style=8
天地图交通|https://t[1-4].tianditu.gov.cn/vec_w/wmts?SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=vec&STYLE=default&TILEMATRIXSET=w&FORMAT=tiles&TILECOL={x}&TILEROW={y}&TILEMATRIX={z}&tk=c03258c0232becff8dfbd108c02a3265
天地图卫星|https://t[1-4].tianditu.gov.cn/img_w/wmts?SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=img&STYLE=default&TILEMATRIXSET=w&FORMAT=tiles&TILECOL={x}&TILEROW={y}&TILEMATRIX={z}&tk=c03258c0232becff8dfbd108c02a3265
天地图地形|https://t[1-4].tianditu.gov.cn/ter_w/wmts?SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=ter&STYLE=default&TILEMATRIXSET=w&FORMAT=tiles&TILECOL={x}&TILEROW={y}&TILEMATRIX={z}&tk=c03258c0232becff8dfbd108c02a3265
天地图注记|https://t[1-4].tianditu.gov.cn/cva_w/wmts?SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=cva&STYLE=default&TILEMATRIXSET=w&FORMAT=tiles&TILECOL={x}&TILEROW={y}&TILEMATRIX={z}&tk=c03258c0232becff8dfbd108c02a3265

在主程序加载时,将图层分别绑定到地图和覆盖图上。

 private void InitMapurls()
        {
            string configfile = Application.StartupPath + "\\config.txt";
            if (File.Exists(configfile))
            {
                string[] configlines = File.ReadAllLines(configfile);
                for (int i = 0; i < configlines.Length; i++)
                {
                    if (!configlines[i].StartsWith("//"))
                    {
                        curmapurls.Add(configlines[i].Split('|')[1]);
                        break;
                    }
                }
                DataTable dt = new DataTable();
                dt.Columns.Add("text");
                dt.Columns.Add("value");
                DataTable dt1 = dt.Clone();
                for (int i = 0; i < configlines.Length; i++)
                {
                    if (!configlines[i].StartsWith("//"))
                    {
                        mapurls.Add(configlines[i]);
                        DataRow row = dt.NewRow();
                        row[0] = configlines[i].Split('|')[0];
                        row[1] = configlines[i].Split('|')[1];
                        dt.Rows.Add(row);
                        dt1.Rows.Add(row.ItemArray);
                    }
                }
                CBLayer1.DataSource = dt;
                CBLayer1.DisplayMember = "text";
                CBLayer1.ValueMember = "value";
                CBLayer2.DataSource = dt1;
                CBLayer2.DisplayMember = "text";
                CBLayer2.ValueMember = "value";
            }
            else
            {
                curmapurls.Add("https://a.tile.openstreetmap.org/{z}/{x}/{y}.png");
            }

        }

当图源下拉框变化时,切换地图:

    void changeMap()
        {
            if (isfirtload)
                return;
            curmapurls.Clear();
            curmapurls.Add(((DataRowView)CBLayer1.SelectedItem)[1].ToString());
            if (CBShow.CheckState==CheckState.Checked)
            {
                curmapurls.Add(((DataRowView)CBLayer2.SelectedItem)[1].ToString());
            }
            gmapc.MapProvider = new TmsProvider(curmapurls);
        }

同时,将gmapc.MapProvider =new TmsProvider(curmapurls);设置为自定义图源。其中curmapurls为一个泛型,用来记录右上角选择的地图的地址。

3.2.png

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