Arcgis for Silverlight学习（一）

1.地图的加载

arcgis server for silverlight 通过控件map实现地图的浏览功能。map控件的使用方法如下：

<esri:Map x:Name="MyMap" WrapAround="True" IsLogoVisible="False" Extent="-15000000,2000000,-7000000,8000000"
MouseMove="MyMap_MouseMove" Progress="MyMap_Progress"
ExtentChanged="MyMap_ExtentChanged">
<esri:ArcGISTiledMapServiceLayer ID="MyBaseLayer"
Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer">

</esri:ArcGISTiledMapServiceLayer>

<esri:ArcGISTiledMapServiceLayer ID="Imagery" Visible="False"
Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer" />
<esri:ArcGISDynamicMapServiceLayer ID="MyDynamicLayer"
Url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer">

</esri:ArcGISDynamicMapServiceLayer>
</esri:Map>

在Map对象是地图的容器，在其中可以添加自己需要的地图图层。ArcGISTitleMapServerLayer,可以加载网上在线的地图。ArcgisDinamicLayer可以加载本地的地图。Extent 可以设置地图初始化加载的范围。

2.要素图层的聚合和MapTip

API提供了对图层要素的聚合，还有MapTip功能

<esri:FeatureLayer ID="MyFeatureLayer" IgnoreServiceScaleRange="True"
Url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer/0">

//图层聚合
<esri:FeatureLayer.Clusterer>
<esri:FlareClusterer></esri:FlareClusterer>
</esri:FeatureLayer.Clusterer>

//MapTip
<esri:FeatureLayer.MapTip>
<Border CornerRadius="5" BorderBrush="Black" BorderThickness="1" Background="White">
<TextBlock Text="{Binding [POP2000]}" Foreground="Black" Margin="5"></TextBlock>
</Border>
</esri:FeatureLayer.MapTip>
</esri:FeatureLayer>

3.图层控制

API提供了图层控制功能，通过Legend控件。Legend控件可以以树的形式展示图层，但是并不能对图层进行控制，我们需要设置MapLayerTemplate和LayerTemplate，分别为两个模板绑定DataTemplate

<esri:Legend Map="{Binding ElementName=MyMap}"
LayerItemsMode="Tree"
ShowOnlyVisibleLayers="False" Margin="5,5,5,5">

<esri:Legend.MapLayerTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox Content="{Binding Label}"
IsChecked="{Binding IsEnabled, Mode=TwoWay}"
IsEnabled="{Binding IsInScaleRange}" >
</CheckBox>
</StackPanel>
</DataTemplate>
</esri:Legend.MapLayerTemplate>

<esri:Legend.LayerTemplate>
<DataTemplate>
<CheckBox Content="{Binding Label}"
IsChecked="{Binding IsEnabled, Mode=TwoWay}"
IsEnabled="{Binding IsInScaleRange}" >
</CheckBox>
</DataTemplate>
</esri:Legend.LayerTemplate>
</esri:Legend>

这样一个普通的图层控制工具就有了。

4.LayerAction

API提供了很多LayerAction，下面说说常用的几个LayerAction

距离测量，能够测出要素之间的距离，也称多段线测量，需要地图有空间参考

 

<Button Style="{StaticResource ResourceKey=MenuItem}" Content="MeasurePolyline">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">

//定义距离测量
<esri:MeasureAction MeasureMode="Polyline" MapUnits="Meters"
DistanceUnit="Meters" DisplayTotals="True"
TargetName="MyMap">

</esri:MeasureAction>
</i:EventTrigger>
</i:Interaction.Triggers>
</Button>

面积测量，能够进行面积的测量。需要地图有空间参考，同时需要设置测量的方式，显示的单位，面积单位等。

<Button Style="{StaticResource ResourceKey=MenuItem}" Content="MeasurePolygon">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<esri:MeasureAction MeasureMode="Polygon" MapUnits="Meters"
DistanceUnit="Meters" AreaUnit="SquareMeters"
TargetName="MyMap" DisplayTotals="True"
FillSymbol="{StaticResource DefaultFillSymbol}">

</esri:MeasureAction>
</i:EventTrigger>
</i:Interaction.Triggers>

</Button>

返回全局地图的行为，能够快速返回全局地图

<Button Style="{StaticResource ResourceKey=MenuItem}" Content="ZoomToFullExtent">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<esri:ZoomToFullExtentAction TargetName="MyMap"></esri:ZoomToFullExtentAction>
</i:EventTrigger>
</i:Interaction.Triggers>
</Button>

ZoomToLayer。快速定位到指定的图层

<Button Style="{StaticResource ResourceKey=MenuItem}" Content="Zoom To Layer">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<esri:ZoomToLayerAction LayerID="MyFeatureLayer"
TargetName="MyMap"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</Button>

图层控制Toggle行为，能够控制图层的显示，隐藏指定的图层

<Button Style="{StaticResource MenuItem}" Content="Toogle">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<esri:ToggleLayerAction LayerID="MyDynamicLayer" TargetName="MyMap">
</esri:ToggleLayerAction>
</i:EventTrigger>
</i:Interaction.Triggers>
</Button>

同时API还能够了显示地图坐标的行为，一般不建议采用。可以自己写代码实现类似的功能。

5.地图坐标的显示

先看前台Xaml代码

<Border BorderBrush="Black" BorderThickness="1" CornerRadius="5"
Background="#DD919191" Width="220" Height="100"
HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,200,0,0">
<Border.Effect>
<DropShadowEffect ShadowDepth="2"></DropShadowEffect>
</Border.Effect>
<StackPanel Orientation="Vertical" Margin="5" Background="White">
<TextBlock Text="屏幕坐标"></TextBlock>
<StackPanel Orientation="Horizontal">
<TextBlock Text="X:"></TextBlock>
<TextBlock x:Name="txtX"></TextBlock>
<TextBlock Text="Y:" Margin="3,0,0,0"></TextBlock>
<TextBlock x:Name="txtY"></TextBlock>
</StackPanel>
<StackPanel>
<TextBlock Text="地图坐标"></TextBlock>
</StackPanel>
<StackPanel Orientation="Horizontal">
<TextBlock Text="X:"></TextBlock>
<TextBlock x:Name="MapX"></TextBlock>
<TextBlock Margin="3,0,0,0" Text="Y:"></TextBlock>
<TextBlock x:Name="MapY"></TextBlock>
</StackPanel>
</StackPanel>
</Border>

前台设计坐标的显示，用Textblock显示

后台代码

private void MyMap_MouseMove(object sender, MouseEventArgs e)
{
if (MyMap.Extent != null)
{
System.Windows.Point point = e.GetPosition(MyMap);
txtX.Text = e.GetPosition(MyMap).X.ToString();
txtY.Text = e.GetPosition(MyMap).Y.ToString();
ESRI.ArcGIS.Client.Geometry.MapPoint mapPoint = new ESRI.ArcGIS.Client.Geometry.MapPoint();
mapPoint = MyMap.ScreenToMap(point);
if (MyMap.WrapAroundIsActive)
{
mapPoint = ESRI.ArcGIS.Client.Geometry.Geometry.NormalizeCentralMeridian(mapPoint) as ESRI.ArcGIS.Client.Geometry.MapPoint;
}
if (mapPoint != null)
{

MapX.Text = string.Format("{0}", Math.Round(mapPoint.X, 4));
MapY.Text = string.Format("{0}", Math.Round(mapPoint.Y, 4));
}
}
}

在mouseover事件获取地图的屏幕坐标，通过ScreenToMap 获取地图的坐标。期间需要借助MapPoint实现坐标的从Point转换。使用的时候，需要谨记对象的初始化。

7.获取地图初始化的坐标

有时需要获取地图加载过程中的地图显示范围。通过地图的ExtentChanged事件。

private void MyMap_ExtentChanged(object sender, ExtentEventArgs e)
{
txtExtent.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);
}

8.地图缩放和地图移动的时间设置

通过Api 我们可以设置地图的缩放的时间和地图移动的时间，有时候会有更好的效果。通过Silder控件来实现事件ValueChanged。

private void ZoomAnimation_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
int seconds = Convert.ToInt32(e.NewValue);
MyMap.ZoomDuration = new TimeSpan(0,0,seconds);
lalZoom.Text = string.Format("value:{0}",seconds);
}

private void PanAnimation_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
int sendcons = Convert.ToInt32(e.NewValue);
MyMap.PanDuration = new TimeSpan(0, 0, sendcons);
lalPan.Text = string.Format("Value:{0}",sendcons);
}

前台代码如下：

<Border BorderBrush="Black" BorderThickness="1" Background="DarkGray" HorizontalAlignment="Right" Margin="0,500,0,0" Height="200">
<Border.Effect>
<DropShadowEffect></DropShadowEffect>
</Border.Effect>
<StackPanel Orientation="Vertical" Background="White" Margin="5">
<StackPanel>
<TextBlock Text="设置地图缩放的速度"></TextBlock>
<TextBlock Text="Value:0" x:Name="lalZoom"></TextBlock>
<Slider x:Name="ZoomAnimation" Minimum="0" Maximum="20" SmallChange="1" LargeChange="5"
Width="200" Cursor="Hand" ValueChanged="ZoomAnimation_ValueChanged"></Slider>
</StackPanel>
<StackPanel>
<TextBlock Text="设置地图移动速度"></TextBlock>
<TextBlock Text="Value:0" x:Name="lalPan"></TextBlock>
<Slider x:Name="PanAnimation" Minimum="0" Maximum="20" SmallChange="1" LargeChange="5"
Width="200" Cursor="Hand" ValueChanged="PanAnimation_ValueChanged"></Slider>
</StackPanel>
</StackPanel>
</Border>

8.地图加载的进度条

当我们需要加载海量的地理信息数据时，地图加载的速度会变慢许多，这时候就需要地图进度条来实时显示地图加载的过程。API为我们提供了MapProcess，

为该控件绑定地图对象即可

 <!--<esri:MapProgressBar Width="150" Map="{Binding ElementName=MyMap}" Height="30"></esri:MapProgressBar>-->

也可以使用silverlight的ProcessBar控件来实现。这时需要借助map的process事件。

前台代码

<ProgressBar Minimum="0" Maximum="100" Width="150" Height="30" x:Name="MyProcess"></ProgressBar>
<TextBlock x:Name="txtProcess" Text="100%" HorizontalAlignment="Center" VerticalAlignment="Center"></TextBlock>

后台代码

private void MyMap_Progress(object sender, ProgressEventArgs e)
{
if (e.Progress < 100)
{
processGrid.Visibility = Visibility.Visible;

//获取处理的进程
MyProcess.Value = e.Progress;
txtProcess.Text = string.Format("正在加载地图：{0}%", e.Progress);
}
else
{
processGrid.Visibility = Visibility.Collapsed;
}
}

10.图层切换

图层切换其实和图层控制是一个道理，有时候，我们需要切换图层，比如从影像图切换到TitleLayer等。一般通过图层地 Visiable来设置。

前台代码

<StackPanel Margin="5" Background="White" Orientation="Horizontal">

//通过radiobutton进行图层切换
<RadioButton x:Name="radImage" Content="卫星影像" Click="radImage_Click"></RadioButton>
<RadioButton x:Name="radTitle" Content="矢量地图" Click="radImage_Click"></RadioButton>
</StackPanel>

后代代码

private void radImage_Click(object sender, RoutedEventArgs e)
{

//实例化radiobutton控件
RadioButton radioButton = sender as RadioButton;

//radiobutton的name判断
switch (radioButton.Name)
{
case"radImage":
MyMap.Layers["MyBaseLayer"].Visible = false;
MyMap.Layers["Imagery"].Visible = true;
break;
case"radTitle":

//图层显示
MyMap.Layers["MyBaseLayer"].Visible = true;
MyMap.Layers["Imagery"].Visible = false;
break;
}
}