ArcGIS API for Silverlight中載入Google地形圖（瓦片圖）

<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專案中的MainPage.xaml.cs檔案內容如下：

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);
        }
    }
}

4、完成以上步驟後，執行，可以看見Google地形圖了，just try it，have fun！

5、補充：這裡使用的是墨卡託座標，而我們經常使用的是經緯度座標，這就需要做轉換，下面提供一個類，WKIDConvert.cs，內容

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
    {
        //經緯度轉墨卡託
        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;
        }

        //墨卡託轉經緯度
        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;
        }
    }
}

然後我們如果要定位到某個城市的話，比如黃山市，其Extent為：117.647738815324,29.4704217183843,118.446182957997,30.4124245048916

我們這裡為MainPage.xaml.cs中新增一行程式碼即可定位到黃山市範圍

private void UserControl_Loaded(object sender, RoutedEventArgs e)
{         

            GoogleTopographicLayer   layer = new GoogleTopographicLayer();

            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、再次補充：在之前的Google地形圖上疊加自定義ArcMap地圖，可以是動態圖也可以是靜態圖，只要加上釋出的地圖，即可顯示，在MainPage.xaml.cs中新增如下幾行程式碼即可。

private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
            //疊加Google地形圖瓦片
            GoogleTopographicLayer layer = new GoogleTopographicLayer();
            myMap.Layers.Add(layer);
            layer.Opacity = 1;

            //載入動態圖
            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)));
}

效果圖如下，這裡只是做了黃山市的市界邊線，主要作用就是在Google地形圖上明顯看出黃山市的範圍：