该实例主要是包含六部分:地图范围、坐标、动画效果、全屏、比例尺、进度条。
前期准备工作
前台代码0
<UserControl x:Class="APIforSilverlightSamp.s2" xmlns="/winfx//xaml/presentation" xmlns:x="/winfx//xaml" xmlns:d="/expression/blend/" xmlns:mc="/markup-compatibility/" xmlns:ESRI="clr-namespace:ESRI.ArcGIS.Client;assembly=ESRI.ArcGIS.Client" mc:Ignorable="d"> <Grid x:Name="LayoutRoot" Background="White"> <ESRI:Map x:Name="mymap"> <ESRI:Map.Layers> <ESRI:ArcGISTiledMapServiceLayer ID="WorldImageLayer" x:Name="WorldImageLayer" Initialized="WorldImageLayer_Initialized" Url="/ArcGIS/rest/services/ESRI_Imagery_World_2D/MapServer" /> </ESRI:Map.Layers> </ESRI:Map> </Grid> </UserControl>
代码<Application.Resources>
<Application.Resources> <Style x:Key="rectBottom" TargetType="Rectangle"> <Setter Property="RadiusX" Value="10" /> <Setter Property="RadiusY" Value="10" /> <Setter Property="Fill" Value="#22000000" /> <Setter Property="Canvas.Left" Value="5" /> <Setter Property="Canvas.Top" Value="5" /> <Setter Property="Width" Value="215" /> <Setter Property="Height" Value="110" /> </Style> <Style x:Key="rectMiddle" TargetType="Rectangle"> <Setter Property="RadiusX" Value="10" /> <Setter Property="RadiusY" Value="10" /> <Setter Property="Fill" Value="#775C90B2" /> <Setter Property="Canvas.Left" Value="0" /> <Setter Property="Canvas.Top" Value="0" /> <Setter Property="Width" Value="215" /> <Setter Property="Height" Value="110" /> <Setter Property="Stroke" Value="Gray" /> </Style> <Style x:Key="rectTop" TargetType="Rectangle"> <Setter Property="RadiusX" Value="5" /> <Setter Property="RadiusY" Value="5" /> <Setter Property="Fill" Value="#FFFFFFFF" /> <Setter Property="Canvas.Left" Value="10" /> <Setter Property="Canvas.Top" Value="10" /> <Setter Property="Width" Value="195" /> <Setter Property="Height" Value="90" /> <Setter Property="Stroke" Value="DarkGreen" /> </Style> </Application.Resources>
1.地图范围
前台代码1所有的布局工作都在一个Grid中进行,给它起个名字叫LayoutRoot。Grid里面放了一个ESRI:Map元素(Map控件),它继承自Silverlight的Control,所以拥有Width和Height属性,默认是Auto,自动填充整个Grid。Map.Layers是一个集合,可以往里面添加layer,这里的layer指的是ArcGIS Server或其他软件发布的地图服务,目前SilverlightAPI中支持的能够直接使用的有ArcGISDynamicMapServiceLayer,ArcGISTiledMapServiceLayer,ArcGISImageServiceLayer,分别对应ArcGIS Server发布的动态地图服务,缓存地图服务(两种Map Service)和ImageService,这三种图层是拿来即用的,如果你想加入别的地图服务,比如WMS服务,则需要自己继承相应类型的的Layer;此外还有GraphicsLayer,ElementLayer,SilverlightAPI特有的FeatureLayer等。
后台代码1
private void WorldImageLayer_Initialized(object sender, EventArgs e) { Map1.ExtentChanged += new EventHandler<ESRI.ArcGIS.ExtentEventArgs>(Map1_ExtentChange); Map1.ExtentChanging += new EventHandler<ESRI.ArcGIS.ExtentEventArgs>(Map1_ExtentChange); } private void Map1_ExtentChange(object sender, ESRI.ArcGIS.ExtentEventArgs e) { TBextent.Text = string.Format("地图范围:\nMinX:{0}\nMinY:{1}\nMaxX:{2}\nMaxY:{3}", e.NewExtent.XMin, e.NewExtent.YMin, e.NewExtent.XMax, e.NewExtent.YMax); }
Map控件里面已经封装了一些事件来供我们使用,我们可以在需要的时候捕获它们来进行处理。如果做过ArcGIS产品的二次开发,你应该已经想到我们要捕获的就是Map的ExtentChanged事件;而要在地图移动或者缩放的过程中也实时显示地图范围,则还要对ExtentChanging事件做处理。
2.地图坐标
前台代码2
<!--mouse coords--> <Canvas Width="215" Height="110" Margin="0,120,0,0" VerticalAlignment="Top"> <Rectangle Style="{StaticResource rectBottom}" /> <Rectangle Style="{StaticResource rectMiddle}" /> <Rectangle Style="{StaticResource rectTop}" /> <StackPanel Orientation="Vertical" Margin="20,15,15,0"> <TextBlock x:Name="TBscreencoords" HorizontalAlignment="Left" VerticalAlignment="Center" Text="屏幕坐标:" TextWrapping="Wrap" FontWeight="Bold" /> <TextBlock x:Name="TBmapcoords" HorizontalAlignment="Left" VerticalAlignment="Center" Text="地图坐标:" TextWrapping="Wrap" FontWeight="Bold" /> </StackPanel> </Canvas>
那么接下来要捕捉那个事件呢?当然就是MouseMove啦。不过如果查看SilverlightAPI中的Map类,发现并没有这个事件。但要记住Map是继承自xaml中的Control,Control继承自FrameworkElement,FrameworkElement继承自UIElement,这里就有一个MouseMove事件了。所以Map控件的MouseMove是xaml中而不是Siverlight API中的事件(当然整个SilverlightAPI都是建立在xaml基础上的)。在ESRI:Map标签中添加一个MouseMove事件<ESRI:Map x:Name="Map1" MouseMove="Map1_MouseMove">
后台代码2
private void Map1_MouseMove(object sender, MouseEventArgs e) { if (Map1.Extent != null) { System.Windows.Point screenPnt = e.GetPosition(Map1); TBscreencoords.Text = string.Format("屏幕坐标:\nX:{0},Y:{1}", screenPnt.X, screenPnt.Y); ESRI.ArcGIS.Geometry.MapPoint mapPnt = Map1.ScreenToMap(screenPnt); TBmapcoords.Text = string.Format("地图坐标:\nX:{0}\nY:{1}", Math.Round(mapPnt.X, 4), Math.Round(mapPnt.Y, 4)); } }
可以看到Map控件提供了屏幕与地图坐标之间转换的方法,好比开发人员的一座桥梁,用来往返于Silverlight特性与地图之间,非常方便。需要说明的是,这里GetPosition(Map1)获得的屏幕坐标是相对于Map控件的,而不是显示器的左上角。ok,继续来看第三部分。
3.Map里的动画效果
前台代码3
<!--map animation slider--> <Canvas Width="215" Height="130" Margin="0,240,0,0" VerticalAlignment="Top"> <Rectangle Style="{StaticResource rectBottom}" Height="130" /> <Rectangle Style="{StaticResource rectMiddle}" Height="130" /> <Rectangle Style="{StaticResource rectTop}" Height="110" /> <StackPanel Orientation="Vertical" Margin="20,15,15,0"> <TextBlock HorizontalAlignment="Left" Text="设置地图缩放动作持续时间:" TextWrapping="Wrap" FontWeight="Bold" /> <TextBlock x:Name="TBzoomdurationvalue" HorizontalAlignment="Left" Text="当前值:" TextWrapping="Wrap" FontWeight="Bold" /> <Slider x:Name="sliderzoomanimation" Orientation="Horizontal" Minimum="0" Maximum="20" SmallChange="1" LargeChange="5" Cursor="Hand" ValueChanged="slideranimation_ValueChanged" Width="180" /> <TextBlock HorizontalAlignment="Left" Text="设置地图平移动作持续时间:" TextWrapping="Wrap" FontWeight="Bold" /> <TextBlock x:Name="TBpandurationvalue" HorizontalAlignment="Left" Text="当前值:" TextWrapping="Wrap" FontWeight="Bold" /> <Slider x:Name="sliderpananimation" Orientation="Horizontal" Minimum="0" Maximum="20" SmallChange="1" LargeChange="5" Cursor="Hand" ValueChanged="slideranimation_ValueChanged" Width="180" /> </StackPanel> </Canvas>
当地图放大和平移时都可以看到平滑的效果,这归功于Silverlight的动画功能。Map在封装完动画效果后,给了我们两个属性来对它们进行设置:PanDuration和ZoomDuration,用于设置这两个动作持续的时间。它们都是TimeSpan类型的变量,合理的设置可以带来良好的用户体验。
后台代码3
private void slideranimation_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e) { Slider s = sender as Slider; if (s.Name == "sliderzoomanimation") { Map1.ZoomDuration = new TimeSpan(0, 0, Convert.ToInt32(sliderzoomanimation.Value)); TBzoomdurationvalue.Text = string.Format("当前值:{0}秒", Convert.ToInt32(sliderzoomanimation.Value)); } else { Map1.PanDuration = new TimeSpan(0, 0, Convert.ToInt32(sliderpananimation.Value)); TBpandurationvalue.Text = string.Format("当前值:{0}秒", Convert.ToInt32(sliderpananimation.Value)); } }
对应着地图效果,应该很容易理解。但是细心的朋友可能会发现,初始时值没有显示,不要紧,有办法解决,在页面初始函数中加入下面两句就可以了
TBzoomdurationvalue.Text = string.Format("当前值:{0}.{1}秒", Map1.ZoomDuration.Seconds, Map1.ZoomDuration.Milliseconds);
TBpandurationvalue.Text = string.Format("当前值:{0}.{1}秒", Map1.PanDuration.Seconds, Map1.PanDuration.Milliseconds);
4.设置全屏
前台代码4
<!--operation info--> <Canvas Width="215" Height="110" Margin="0,0,0,30" VerticalAlignment="Bottom"> <Rectangle Style="{StaticResource rectBottom}" /> <Rectangle Style="{StaticResource rectMiddle}" Fill="#77FF0000" /> <Rectangle Style="{StaticResource rectTop}" /> <TextBlock Margin="20,15,15,0" Text="地图操作提示: " > <LineBreak></LineBreak>双击放大 <LineBreak></LineBreak>Shift+拖拽:放大到指定范围 <LineBreak></LineBreak> Ctrl+Shift+拖拽:缩小到指定范围 </TextBlock> <ToggleButton x:Name="TBfullscreen" Content="点击切换地图全屏" HorizontalAlignment="Center" Canvas.Left="100" Canvas.Top="15" Height="30" Click="TBfullscreen_Click" /> </Canvas>
把以上代码放到Gridright Grid中
后台代码:
private void TBfullscreen_Click(object sender, RoutedEventArgs e) { System.Windows.Interop.Content content = Application.Current.Host.Content; content.IsFullScreen=!content.IsFullScreen; }
5.比例尺
前台代码5
<!--scale bar 放在LayoutRoot Grid中-->
<Canvas HorizontalAlignment="Left" VerticalAlignment="Bottom" Margin="10,0,0,20">
<ESRI:ScaleBar x:Name="scalebar" MapUnit="DecimalDegrees" DisplayUnit="Kilometers" Background="Red" FillColor1="Black" FillColor2="White" FontSize="14" TextColor="Black"/>
</Canvas>
在页面初始函数中加入
scalebar.Map = Map1;
6.进度条
前台代码6
<!--progressbar 放在LayoutRoot中-->
<Grid HorizontalAlignment="Center" x:Name="progressGrid" VerticalAlignment="Center" Width="200" Height="20" Margin="5,5,5,5">
<ProgressBar x:Name="MyProgressBar" Minimum="0" Maximum="100" />
<TextBlock x:Name="ProgressValueTextBlock" Text="100%" HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid> 在ESRI:Map标签中添加一个Progress事件
<ESRI:Map x:Name="Map1" MouseMove="Map1_MouseMove" Progress="Map1_Progress" >
后台代码6
private void Map1_Progress(object sender, ESRI.ArcGIS.Client.ProgressEventArgs e)
{
if (e.Progress < 100)
{
progressGrid.Visibility = Visibility.Visible;
MyProgressBar.Value = e.Progress;
ProgressValueTextBlock.Text = String.Format("正在处理 {0}%", e.Progress);
}
else
{
progressGrid.Visibility = Visibility.Collapsed;
}
}
按照上面的步骤,就可以实现地图的一些基本操作,效果如开始的图片所示,在添加前台代码时注意添加的位置。我现在也是刚刚开始学习,欢迎大家提出问题,交流学习心得
事例源码下载
参考资料:/en/webapi/silverlight/apiref/ESRI.ArcGIS.Client~ESRI.ArcGIS.Client.ScaleBar~TextColor.html
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