我們知道通過ADF是可以擷取地圖的圖例的,但如果使用ArcGIS Server API for JavaScript等非ADF方式的時候,如何擷取圖例呢?今天發現通過SOAP方式可以獲得圖例,以VS2005為例,實作方式如下:
1、首先在項目中添加Web引用,ArcGIS Server的Web Services引用位址一般是以下方式:http://<Web Server Hostname>/<ArcGIS Instance>/services/<ServiceName>/MapServer?wsdl,添加後,我們就可以像平常使用本地類一樣使用Web Services類了。
2、然後在web界面上放幾個顯示圖檔的Image控件,用于顯示圖例圖檔
3、然後我們可以使用以下代碼來實作擷取圖例的操作
wsmap.ESRI_Census_USA_MapServer mapservice = new ESRI_Census_USA_MapServer();
mapservice.Url = "http://sampleserver1.arcgisonline.com/ArcGIS/services/Demographics/ESRI_Census_USA/MapServer";
string mapname = mapservice.GetDefaultMapName();
MapServerInfo mapinfo = mapservice.GetServerInfo(mapname);
MapDescription mapdesc = mapinfo.DefaultMapDescription;
ImageType imgtype = new ImageType();
imgtype.ImageFormat = esriImageFormat.esriImagePNG;
imgtype.ImageReturnType = esriImageReturnType.esriImageReturnURL;
LayerDescription[] layerdescriptions = mapdesc.LayerDescriptions;
int[] layerids = new int[layerdescriptions.Length];
int i = 0;
foreach (LayerDescription layerdesc in layerdescriptions)
{
layerids.SetValue(layerdesc.LayerID, i++);
}
MapServerLegendPatch legendpatch = new MapServerLegendPatch();
legendpatch.ImageDPI = 96;
legendpatch.Height = 24;
legendpatch.Width = 24;
MapServerLegendInfo[] legendinfo = mapservice.GetLegendInfo(mapname, layerids, legendpatch, imgtype);
Image1.ImageUrl = legendinfo[0].LegendGroups[0].LegendClasses[0].SymbolImage.ImageURL;
Label1.Text = legendinfo[0].LegendGroups[0].LegendClasses[0].Label;
Image2.ImageUrl = legendinfo[0].LegendGroups[0].LegendClasses[1].SymbolImage.ImageURL;
Label2.Text = legendinfo[0].LegendGroups[0].LegendClasses[1].Label;
Image3.ImageUrl = legendinfo[0].LegendGroups[0].LegendClasses[2].SymbolImage.ImageURL;
Label3.Text = legendinfo[0].LegendGroups[0].LegendClasses[2].Label;
Label4.Text = legendinfo[0].LegendGroups[0].Heading;
以下是結果圖檔: