• arcgis for silverlight 控制图层显示级别


      在GIS项目中,如果加载两个图层,一个为切片图层(做为底图),另一个为动态图层,动态图层一般没有设置能够缩放到的比例,就会出现底图空白的情况,那么,是什么原因出现底图为空白的呢?

      切片图层早已规定好能够达到的最大比例尺以及最小比例尺,级别已经是固定的了。所以在动态底图里面放大或缩小时就会出现空白。

      解决方式:

      根据切片图层来控制整个地图能够进行放大或缩小的范围:重载ArcGISTiledMapServiceLayer类

      后台代码:

    public class ControlArcGiSTitleLayerLevel : ArcGISTiledMapServiceLayer
        {
            //最小Level
            private int MinLevel = 0;
            //最大Level
            private int MaxLevel = 1;
    
            //目前使用的rest服务共有11个级别 MaxLevel 最大可到10
    
            public override void Initialize()
            {
                base.Initialize();
    
                //实际使用中可以不注册此事件 ,只是看Level数值
                this.TileLoading -= new EventHandler<TileLoadEventArgs>(ControlArcGiSTitleLayerLevel_TileLoading);
                this.TileLoading += new EventHandler<TileLoadEventArgs>(ControlArcGiSTitleLayerLevel_TileLoading);
    
                this.Map.Loaded -= new RoutedEventHandler(Map_Loaded);
                this.Map.Loaded += new RoutedEventHandler(Map_Loaded);
            }
    
            void Map_Loaded(object sender, RoutedEventArgs e)
            {
                //this.TileInfo.Lods 代表有多少个Level级别
                //控制
                Lod[] lod = this.TileInfo.Lods.Clone() as Lod[];
                Lod[] newlod = new Lod[MaxLevel + 1];
                //Resolution 随着比例尺的逐渐变大而更小
                for (int i = 0; i < newlod.Length; i++)
                {
                    newlod[i] = lod[i];
                    if (i == MinLevel) //Resolution 随着Level的逐渐变大而更小 所以Level越小 Resolution 越大
                        this.Map.MaximumResolution = lod[i].Resolution;
                    if (i == MaxLevel) //Resolution 随着Level的逐渐变大而更小 所以Level越大 Resolution 越小
                        this.Map.MinimumResolution = lod[i].Resolution;
                }
                this.TileInfo.Lods = newlod;
            }
    
            void ControlArcGiSTitleLayerLevel_TileLoading(object sender, TiledLayer.TileLoadEventArgs e)
            {
                string message = string.Concat("Level:", e.Level, ",Scale:", this.Map.Scale, ",Resolution:", this.Map.Resolution);
                System.Diagnostics.Debug.WriteLine(message);
            }
        }

    Xaml:

    <UserControl x:Class="ControlMapLevel.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="clr-namespace:ESRI.ArcGIS.Client;assembly=ESRI.ArcGIS.Client"
        xmlns:local="clr-namespace:ControlMapLevel"
        d:DesignHeight="300" d:DesignWidth="400">
        <Grid x:Name="LayoutRoot" Background="White">
            <esri:Map x:Name="mapctl">
                <esri:Map.Layers>
                    <local:ControlArcGiSTitleLayerLevel Url="http://localhost/arcgis/rest/services/ScSummaryService/MapServer"></local:ControlArcGiSTitleLayerLevel>
                    <esri:ArcGISDynamicMapServiceLayer Url="http://localhost/arcgis/rest/services/testdymic/MapServer"></esri:ArcGISDynamicMapServiceLayer>
                </esri:Map.Layers>
            </esri:Map>
        </Grid>
    </UserControl>
  • 相关阅读:
    hdu2988:Dark roads(最小生成树)
    hdu1596:find the safest road(最短路)
    hdu1596:find the safest road(最短路)
    CultureInfo中重要的InvariantCulture
    c#通过反射获取类上的自定义特性
    分享我们项目中基于EF事务机制的架构 【转载】
    ASP.NET MVC3中的路由系统(Routes) .
    为ASP.NET MVC应用添加自定义路由
    Mvc生成页面之t4模板相关
    LINQ to SQL语句对应SQL的实现
  • 原文地址:https://www.cnblogs.com/zhangbingCoder/p/3386626.html
Copyright © 2020-2023  润新知