Arcgis silverlight-5 layers总结

layers总结

   

    arcserver silverlight中，一个map由不同地图服务叠加组成，第一次加载的服务地图在最下方，最后加载的服务地图在最上方。每个地图服务又包含不同的地图图层。

    arcserver silverlight layer主要为分两种

    1）layer，指一个地图服务，相当于一个mxd文件，有ArcGISTiledMapServiceLayer，ArcGISDynamicMapServiceLayer，ArcGISImageServiceLayer三种类型，分别代表cached map service（已经生成地图缓存的map service）、non-cached map service（动态图层）和map imagery layer（影像图层）。

    2）Sublayer，指代广义上的图层（lyr），相当于每个服务（mxd文件）中的一个图层

 

以下分别进行介绍，设定当前网页map名称为mymap：

 

1、layer操作

1）控制不同layer的显示和透明度（例子参见Arcgis silverlight-3 ）

方法：一般情况下用控件绑定mymap的layers，控制layer显示就拿控件绑定layer的visible属性，控制透明度就绑定layer的opacity

例如以下例子，用ListBox控件绑定mymap的layers属性，里面包含一个CheckBox和Slider，分别绑定layer的visible和opacity属性

 eg：

 

代码

   < ListBox x:Name = " MyList "  ItemsSource = " {Binding ElementName=MyMap, Path=Layers} " >
                 < ListBox.ItemTemplate >
                     < DataTemplate >
                         < StackPanel Orientation = " Horizontal " >
                             <!-- Layer visibility checkbox -->
                             < CheckBox IsChecked = " {Binding Visible, Mode=TwoWay} "   />
                             <!-- Opacity slider -->
                             < Slider Margin = " -5,0,0,0 "  Minimum = " 0 "  Maximum = " 1 "  Width = " 30 "  
                                Value = " {Binding Opacity, Mode=TwoWay} "  Height = " 18 "   />
                             <!-- Layer name -->
                             < TextBlock Text = " {Binding ID, Mode=OneWay} "  Margin = " 5,0,0,0 "   >  
                             <!--  Tooltip on hover -->
                                 < ToolTipService.ToolTip >
                                     < StackPanel MaxWidth = " 400 " >
                                         < TextBlock FontWeight = " Bold "  Text = " {Binding CopyrightText} "  TextWrapping = " Wrap "   />
                                         < TextBlock Text = " {Binding Description} "  TextWrapping = " Wrap "   />
                                     </ StackPanel >
                                 </ ToolTipService.ToolTip >
                             </ TextBlock >
                         </ StackPanel >
                     </ DataTemplate >
                 </ ListBox.ItemTemplate >
             </ ListBox >

 

2）不同layer之间的切换，每次只显示一个layer（一个地图服务）（例子参见http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#SwitchMap）

方法：一般情况下用选择型控件（RadioButton），当这个控件触发时，调用一个函数，切换当前地图服务的url

eg：

 

代码

private   void  RadioButton_Click( object  sender, RoutedEventArgs e)
        {
             //  Get the Tag from the selected radio button.  The Tag value
             //  cooresponds to the index value of a layer in the map.  
             int  index  =  Convert.ToInt32(((RadioButton)sender).Tag);

            ArcGISTiledMapServiceLayer arcgisLayer  =  MyMap.Layers[ " AGOLayer " ]  as  ArcGISTiledMapServiceLayer; // 视情况决定layer类型，TiledMapServiceLayer or dynamicLayer等

             switch  (index)
            {
                 case   0 :
                    arcgisLayer.Url  =   " http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer " ;
                     break ;
                 case   1 :
                    arcgisLayer.Url  =   " http://server.arcgisonline.com/ArcGIS/rest/services/NGS_Topo_US_2D/MapServer " ;
                     break ;
                 case   2 :
                    arcgisLayer.Url  =   " http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_Imagery_World_2D/MapServer " ;
                     break ;
            }
        }

 

 

3）动态加载layer（地图服务）（例子参见http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#AddLayerDynamically）

方法：在MyMap.Layers中添加地图服务的url

eg：

 

代码

private   void  AddLayerButton_Click( object  sender, RoutedEventArgs e)
        {
             // MyMap.Layers.Clear();  // 首先清空MyMap的所有Layers，如果希望地图只包含新添加的图层，可以添加这一句

            ESRI.ArcGIS.Client.ArcGISTiledMapServiceLayer NewTiledLayer  =   new  ESRI.ArcGIS.Client.ArcGISTiledMapServiceLayer(); // 添加的新图层类型，即是哪种地图服务

            MyMap.Layers.LayersInitialized  +=  (evtsender, args)  => // 以下4行将地图显示范围调整到新添加图层的范围，这个必须后添加的图层空间参考和当前map的空间参考相同，可删掉
            {
                MyMap.ZoomTo(NewTiledLayer.InitialExtent);             

            };

            NewTiledLayer.Url  =  UrlTextBox.Text; // 新添加的图层服务url
            MyMap.Layers.Add(NewTiledLayer); // 将图层添加到mymap的layers中

        }

 

2、Sublayer操作

1）控制不同Sublayer的显示（例子参见Arcgis silverlight-4 Sublayerlist ）

 

代码

// 控制地图图层显示，获取CheckBox对应的图层ID，判断是否显示，存储到visibleLayerList，并将结果返回到dynamicServiceLayer.VisibleLayers，即可控制图层显示/不显示
         private   void  CheckBox_Click( object  sender, RoutedEventArgs e) 
        {
            CheckBox tickedCheckBox  =  sender  as  CheckBox;

             string  serviceName  =  tickedCheckBox.Name;
             bool  visible  =  ( bool )tickedCheckBox.IsChecked;

             int  layerIndex  =  ( int )tickedCheckBox.Tag;

            ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer dynamicServiceLayer  =  MyMap.Layers[serviceName]  as
                ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer;

            List < int >  visibleLayerList  =
                dynamicServiceLayer.VisibleLayers  !=   null
                 ?  dynamicServiceLayer.VisibleLayers.ToList() :  new  List < int > ();

             if  (visible)
            {
                 if  ( ! visibleLayerList.Contains(layerIndex))
                    visibleLayerList.Add(layerIndex);
            }
             else
            {
                 if  (visibleLayerList.Contains(layerIndex))
                    visibleLayerList.Remove(layerIndex);
            }

            dynamicServiceLayer.VisibleLayers  =  visibleLayerList.ToArray();
        }
         // 获取ArcGISDynamicMapServiceLayer地图服务初始化时，设定地图的dynamicServiceLayer.VisibleLayers 

         private   void  ArcGISDynamicMapServiceLayer_Initialized( object  sender, EventArgs e)
        {
            ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer dynamicServiceLayer  =
                sender  as  ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer;
             if  (dynamicServiceLayer.VisibleLayers  ==   null )
               dynamicServiceLayer.VisibleLayers  =  GetDefaultVisibleLayers(dynamicServiceLayer);
        }
         // 获取ArcGISDynamicMapServiceLayer服务提供的地图中的可视图层，返回一个可视图层的ID队列
         private   int [] GetDefaultVisibleLayers(ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer dynamicService)
        {
            List < int >  visibleLayerIDList  =   new  List < int > ();
            ESRI.ArcGIS.Client.LayerInfo[] layerInfoArray  =  dynamicService.Layers;
             for  ( int  index  =   0 ; index  <  layerInfoArray.Length; index ++ )
            {
                 if  (layerInfoArray[index].DefaultVisibility)
                    visibleLayerIDList.Add(index);
            }
             return  visibleLayerIDList.ToArray();
        }   

 

 3、element layer

    element layer用来显示一些地图元素，例如在地图上一个点用一个五角星来表示。 element layer也可以调用meida文件，具体在下一节中详细描述。

eg：

 

代码

< esri:Map x:Name = " MyMap " >
     < esri:ArcGISTiledMapServiceLayer ID = " StreetMapLayer "  
                    Url = " http://services.arcgisonline.com/ArcGIS/rest/services/NPS_Physical_World_2D/MapServer " />

     < esri:ElementLayer >     //定义一个element layer
         < esri:ElementLayer.Children >
             <!-- Clickable button -->    //定义一个按钮
             < Button x:Name = " RedlandsButton "  Width = " 20 "  Height = " 20 "  Content = " X "  
                        esri:ElementLayer.Envelope = " -117,34,-117,34 "
                        VerticalAlignment = " Center "  HorizontalAlignment = " Center "
                        Click = " RedlandsButton_Click "   /> //按钮触发一个操作

             <!-- Arrow pointing at Copenhagen from the right -->  //定义一个箭头

             < TextBlock Text = " &lt;= "  HorizontalAlignment = " Right "  
                           FontSize = " 15 "  Foreground = " Blue "  FontWeight = " Bold "
                           esri:ElementLayer.Envelope = " 12.5698,55.6765,12.5698,55.6765 "   />
             <!-- Arrow pointing at Copenhagen from the left -->  //定义一个箭头
             < TextBlock Text = " =&gt; "  HorizontalAlignment = " Left "  
                           FontSize = " 15 "  Foreground = " Blue "  FontWeight = " Bold "
                           esri:ElementLayer.Envelope = " 12.5698,55.6765,12.5698,55.6765 "   />

             <!--  Red box  -  No size specified. Envelope guides the size  -->  //定义一个红色矩形
             < Rectangle Fill = " Red "  esri:ElementLayer.Envelope = " 0,0,10,10 "   />

             <!-- Editable textbox -->   //定义一个可编辑的textbox

             < TextBox Width = " 100 "  Height = " 20 "  esri:ElementLayer.Envelope = " 40,0,40,0 "
                         Text = " Editable text "  HorizontalAlignment = " Right "  VerticalAlignment = " Bottom "   />
         </ esri:ElementLayer.Children >
     </ esri:ElementLayer >

</ esri:Map >

 

 

 

总结

    arcserver silverlight中，layer和Sublayer 处于上下级关系，layer操作调用Mymap.Layers，Sublayer操作调用mapservice.Layers

eg：        

   图层名称                   控制图层显示                   

   layer             Mymap.Layers visible属性

   Sublayer       mapservice.Layers visible图层id序列

 

  element layer用来显示一个地图元素，给定元素位置和元素类型，就可以显示这个元素，地图元素同样也可以触发操作。