ArcGIS API for Silverlight中加载Google地形图（瓦片图

在做水利等行业中，若能使用到Google的地形图那是再合适不过了，下面就介绍如何在ArcGIS API for Silverlight中加载Google地形图。

　　ArcGIS API for Silverlight 中的ArcGISTiledMapServiceLayer图层，继承自TiledMapServiceLayer。如果想实现自己的缓存地图图

　　层，继承它并重载GetTileUrl方法就可以了。ArcGIS API for Silverlight 内部会计算当前访问的缩放等级level，切片二维编号row，col。这些参数暴露给GetTileUrl方法，在这个方法里面设置访问google静态地图的Url地址。

　　1、在Silverlight项目中新建一个文件夹，并添加一个名为GoogleTopographicLayer.cs文件，内容如下：

using System;

using System.Net;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Ink;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

using ESRI.ArcGIS.Client;

using ESRI.ArcGIS.Client.Geometry;

namespace GoogleMap.CommonClass

{

public class GoogleTopographicLayer: TiledMapServiceLayer

{

private const double cornerCoordinate = 20037508.3427892;

private string _baseURL = "t@128"; //google地形图

public override void Initialize()

{

ESRI.ArcGIS.Client.Projection.WebMercator mercator = new ESRI.ArcGIS.Client.Projection.WebMercator();

this.FullExtent = new ESRI.ArcGIS.Client.Geometry.Envelope(-20037508.3427892, -20037508.3427892, 20037508.3427892, 20037508.3427892)

{

SpatialReference = new SpatialReference(102100)

};

//图层的空间坐标系

this.SpatialReference = new SpatialReference(102100);

// 建立切片信息，每个切片大小256*256px，共16级.

this.TileInfo = new TileInfo()

{

Height = 256,

Width = 256,

Origin = new MapPoint(-cornerCoordinate, cornerCoordinate) { SpatialReference = new ESRI.ArcGIS.Client.Geometry.SpatialReference(102100) },

Lods = new Lod[16]

};

//为每级建立方案，每一级是前一级别的一半.

double resolution = cornerCoordinate * 2 / 256;

for (int i = 0; i < TileInfo.Lods.Length; i++)

{

TileInfo.Lods[i] = new Lod() { Resolution = resolution };

resolution /= 2;

}

// 调用初始化函数

base.Initialize();

}

public override string GetTileUrl(int level, int row, int col)

{

//加载t@128初始的地形图

string url = "http://mt" + (col % 4) + ".google.cn/vt/lyrs=" + _baseURL + "&v=w2.114&hl=zh-CN&gl=cn&" + "x=" + col + "&" + "y=" + row + "&" + "z=" + level + "&s=Galil";

if (_baseURL == "s@92")

{

url = "http://mt" + (col % 4) + ".google.cn/vt/lyrs=" + _baseURL + "&v=w2.114&hl=zh-CN&gl=cn&" + "x=" + col + "&" + "y=" + row + "&" + "z=" + level + "&s=Galil";

}

if (_baseURL == "t@128")

{

url = "http://mt" + (col % 4) + ".google.cn/vt/lyrs=" + _baseURL + ",r@169000000&v=w2.114&hl=zh-CN&gl=cn&" + "x=" + col + "&" + "y=" + row + "&" + "z=" + level + "&s=Galil";

}

if (_baseURL == "m@161000000")

{

url = "http://mt" + (col % 4) + ".google.cn/vt/lyrs=" + _baseURL + "&v=w2.114&hl=zh-CN&gl=cn&" + "x=" + col + "&" + "y=" + row + "&" + "z=" + level + "&s=Galil";

}

return string.Format(url);

//调用加载初始的Google街道地图

//string baseUrl = "http://mt2.google.cn/vt/v=w2.116&hl=zh-CN&gl=cn&x={0}&y={1}&z={2}&s=G";

//return string.Format(baseUrl, col, row, level);

}

}

}
　　2、Silverlight项目中的MainPage.xaml文件内容如下：

<UserControl x:Class="GoogleMap.MainPage"

xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

mc:Ignorable="d"

xmlns:esri="http://schemas.esri.com/arcgis/client/2009"

xmlns:controlsToolkit="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Toolkit"

xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk"

xmlns:layer="clr-namespace:GoogleMap.CommonClass"

d:DesignHeight="300" d:DesignWidth="400" Loaded="UserControl_Loaded">

<Grid x:Name="LayoutRoot" Background="White">

<esri:Map x:Name="myMap" IsLogoVisible="False" ZoomDuration="0:00:02" PanDuration="0:00:02">

</esri:Map>

</Grid>

</UserControl>
　　3、Silverlight项目中的MainPage.xaml.cs文件内容如下：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

using TestDZX.CommonClass;

using ESRI.ArcGIS.Client.Geometry;

using ESRI.ArcGIS.Client;

namespace GoogleMap

{

public partial class MainPage: UserControl

{

ESRI.ArcGIS.Client.Projection.WebMercator mercator = new ESRI.ArcGIS.Client.Projection.WebMercator();

public MainPage()

{

InitializeComponent();

}

private void UserControl_Loaded(object sender, RoutedEventArgs e)

{

GoogleTopographicLayerlayer = new GoogleTopographicLayer();

myMap.Layers.Add(layer);

}

5、补充：这里使用的是墨卡托坐标，而我们经常使用的是经纬度坐标，这就需要做转换，下面提供一个类，WKIDConvert.cs，内容 如下： using System; using System.Net; using System.Windows; using System.Windows.C
　　


　　5、补充：这里使用的是墨卡托坐标，而我们经常使用的是经纬度坐标，这就需要做转换，下面提供一个类，WKIDConvert.cs，内容

　　如下：

using System;

using System.Net;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Ink;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

using ESRI.ArcGIS.Client.Geometry;

namespace GoogleMap.CommonClass

{

public static class WKIDConvert

{

//经纬度转墨卡托

public static MapPoint lonlat2mercator(MapPoint lonlat)

{

MapPoint mercator = new MapPoint();

double X = lonlat.X * 20037508.34 / 180;

double Y = Math.Log(Math.Tan((90 + lonlat.Y) * Math.PI / 360)) / (Math.PI / 180);

Y = Y * 20037508.34 / 180;

mercator.X = X;

mercator.Y = Y;

return mercator;

}

//墨卡托转经纬度

public static MapPoint mercator2lonlat(MapPoint mercator)

{

MapPoint lonlat = new MapPoint();

double X = mercator.X / 20037508.34 * 180;

double Y = mercator.Y / 20037508.34 * 180;

Y = 180 / Math.PI * (2 * Math.Atan(Math.Exp(Y * Math.PI / 180)) - Math.PI / 2);

lonlat.X = X;

lonlat.Y = Y;

return lonlat;

}

}

}
　　然后我们如果要定位到某个城市的话，比如黄山市，其Extent为：117.647738815324,29.4704217183843,118.446182957997,30.4124245048916

　　我们这里为MainPage.xaml.cs中添加一行代码即可定位到黄山市范围

private void UserControl_Loaded(object sender, RoutedEventArgs e)

{

GoogleMapLayer layer = new GoogleMapLayer();

myMap.Layers.Add(layer);

myMap.Extent = new Envelope(WKIDConvert.lonlat2mercator(new MapPoint(117.647738815324, 29.4704217183843)), WKIDConvert.lonlat2mercator(new MapPoint(118.446182957997, 30.4124245048916)));

}
　　6、再次补充：在之前的Google地形图上叠加自定义ArcMap地图，可以是动态图也可以是静态图，只要加上发布的地图，即可显示，在MainPage.xaml.cs中添加如下几行代码即可。

private void UserControl_Loaded(object sender, RoutedEventArgs e)

{

//叠加Google地形图瓦片

GoogleMapLayer layer = new GoogleMapLayer();

myMap.Layers.Add(layer);

layer.Opacity = 1;

//加载动态图

ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer dLayer = new ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer();

myMap.Layers.LayersInitialized += (evtsender, args) =>

{

myMap.ZoomTo(dLayer.InitialExtent);

};

dLayer.Url = "http://localhost/arcgis/rest/services/HS/MapServer/";

myMap.Layers.Add(dLayer);

dLayer.Opacity = 1;

myMap.Extent = new Envelope(WKIDConvert.lonlat2mercator(new MapPoint(117.647738815324, 29.4704217183843)), WKIDConvert.lonlat2mercator(new MapPoint(118.446182957997, 30.4124245048916)));

}
　　效果图如下，这里只是做了黄山市的市界边线，主要作用就是在Google地形图上明显看出黄山市的范围：

　　



　　本文来自taomanman的博客，原文地址：http://blog.csdn.net/taomanman/article/details/8019687