在MIX08上,Chris Pendlenton演示了一款Silverlight地图控件,给大家留下了深刻的印象。时隔一年,在MIX09上,微软终于发布了这款名叫“Virtual Earth Silverlight Map Control”的Silverlight控件技术预览版。
Virtual Earth Silverlight Map Control将Virtual Earth融入了Silverlight,使开发者不必再去使用大量麻烦的Javascript API来开发Virtual Earth应用了。除此之外,它还具有以下优点:
- 对数据和地图进行动画开发;
- 可缩放的界面,包括将来的移动版;
- 深入整合视频、音频和图像,不仅仅是弹出层;
- 支持自定义主题的地图控件;
- 跨浏览器支持,不再需要考虑 CSS Hack 和跨浏览器的 JavaScript 问题。
这个控件的应用非常简单。下面我们就打开Visual Studio 2008,随便试试吧!
效果图:(围观链接:http://azuredrive.blob.core.windows.net/netdrive1/file_e31368a2-988b-4429-b75b-2eb865185c76.html 注:该控件是同时支持Silverlight 2.0和3.0的,但本例中我使用了3.0)
第一步:打开VS2008,新建Silverlight项目。(2.0与3.0的Silverlight Tools均可)
第二步:添加对Microsoft.VirtualEarth.MapControl.dll的引用。
Microsoft.VirtualEarth.MapControl.dll位于Virtual Earth Silverlight Map Control (CTP) SDK安装路径内。
第三步:在Silverlight的MainPage.xaml(2.0中是Page.xaml)中插入地图控件。
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:m="clr-namespace:Microsoft.VirtualEarth.MapControl;assembly=Microsoft.VirtualEarth.MapControl">
<Grid x:Name="LayoutRoot" Background="White">
<m:Map/>
</Grid>
</UserControl>
如果你F5运行它的话,你已经可以看到Virtual Earth地图呈现在你的Silverlight项目里了。我们还要做更多。
第四步:拖入一些简单的控件。
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:VirtualEarth="clr-namespace:Microsoft.VirtualEarth.MapControl;assembly=Microsoft.VirtualEarth.MapControl"
Width="700" Height="500">
<Grid x:Name="LayoutRoot" Background="White">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="40" />
<RowDefinition Height="40" />
</Grid.RowDefinitions>
<VirtualEarth:Map x:Name="viewMap" Mode="AerialWithLabels" Grid.Column="0" Grid.Row="0" Grid.RowSpan="3" Padding="5"
View="29.544,106.518,0.0000 14.0000 0.0000" MouseDoubleClick="MapWithImages_MouseDoubleClick" />
<StackPanel Orientation="Horizontal" Opacity="0.7" Grid.Column="0" Grid.Row="1" HorizontalAlignment="Center">
<Button x:Name="btnNorthAmerica" Click="ChangeMapView_Click" Tag="39.89341,116.33235,0.0000 14.0000 0.0000"
Margin="5" Height="20" >
<TextBlock>北京</TextBlock>
</Button>
<Button x:Name="btnChengdu" Click="ChangeMapView_Click" Tag="30.67,104.074,0.0000 14.0000 0.0000" Margin="5" Height="20" >
<TextBlock>成都</TextBlock>
</Button>
<Button x:Name="btnShanghai" Click="ChangeMapView_Click" Tag="31.10,121.411,0.0000 13.0000 0.0000" Margin="5" Height="20" >
<TextBlock>上海</TextBlock>
</Button>
<Button x:Name="btnVancouver" Click="ChangeMapView_Click" Tag="29.544,106.518,0.0000 14.0000 0.0000" Margin="5" Height="20" >
<TextBlock>重庆</TextBlock>
</Button>
</StackPanel>
<StackPanel Orientation="Horizontal" Opacity="0.9" Grid.Column="0" Grid.Row="2" HorizontalAlignment="Center">
<TextBlock Text="双击地图可以添加图钉。 更改经纬度后可点击Fly to换位置. " Padding="5" Foreground="Red" Width="178" TextWrapping="Wrap"/>
<TextBlock Text="Latitude: " Padding="12" Foreground="Red" />
<TextBox x:Name="txtLatitude" Text="" Height="20" />
<TextBlock Text="Longitude: " Padding="12" Foreground="Red" />
<TextBox x:Name="txtLongitude" Text="" Height="20" />
<Button x:Name="btnFlyto" Click="btnFlyto_Click" Foreground="Red" Margin="5" Height="20" >
<TextBlock>Fly to</TextBlock>
</Button>
</StackPanel>
</Grid>
</UserControl>
第五步:写后台代码。
using System.Windows;
using System.Windows.Controls;
using System.Globalization;
using Microsoft.VirtualEarth.MapControl;
using Microsoft.VirtualEarth.MapControl.Design;
using System.Windows.Media;
using System.Windows.Media.Imaging;
namespace SLLiveEarthControl
{
public partial class MainPage : UserControl
{
LocationConverter locConverter = new LocationConverter();
// Converts the Button's location Tag to a map view..
MapViewSpecificationConverter viewConverter = new MapViewSpecificationConverter();
private MapLayer imageLayer = new MapLayer();
public MainPage()
{
InitializeComponent();
viewMap.AddChild(imageLayer);
viewMap.ViewChangeOnFrame += new EventHandler<MapEventArgs>(viewMap_ViewChangeOnFrame);
viewMap.AnimationLevel = AnimationLevel.Full;
}
private void viewMap_ViewChangeOnFrame(object sender, MapEventArgs e)
{
Map map = sender as Map;
if (map != null)
{
MapViewSpecification mapViewSpec = map.View;
// 根据地图当前的状态动态改变txtLatitude和txtLongitude的值
txtLatitude.Text = string.Format(CultureInfo.InvariantCulture,
"{0:F5}", mapViewSpec.Center.Latitude);
txtLongitude.Text = string.Format(CultureInfo.InvariantCulture,
"{0:F5}", mapViewSpec.Center.Longitude);
}
}
private void ChangeMapView_Click(object sender, RoutedEventArgs e)
{
viewMap.View = (MapViewSpecification)viewConverter.ConvertFrom(((Button)sender).Tag);
}
private void MapWithImages_MouseDoubleClick(object sender, MapMouseEventArgs e)
{
e.Handled = true;
Location pinLocation = viewMap.ViewportPointToLocation(e.ViewportPoint);
Image pin = new Image();
Random r = new Random();
pin.Source = new BitmapImage(new Uri(r.Next() % 2==0 ? "female.png" : "male.png", UriKind.RelativeOrAbsolute));
pin.Stretch = Stretch.None;
imageLayer.AddChild(pin, pinLocation, PositionMethod.BottomCenter);
}
private void btnFlyto_Click(object sender, RoutedEventArgs e)
{
viewMap.View = new MapViewSpecification(new Location(Double.Parse(txtLatitude.Text), Double.Parse(txtLongitude.Text)), 14);
}
}
}
你可能已经注意到,我们在编程时已经完全脱离了Javascript;Virtual Earth在我们的手中,已经变得和TextBox,DataGrid一样,只是一个控制非常方便的控件了。 : )
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附件:
本例代码下载:SLLiveEarthControl.rar