addlayer.cs

动态添加图层（arcgis server）

using System; 
using System.Data; 
using System.Configuration; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 
using ESRI.ArcGIS.Server; 
using ESRI.ArcGIS.Utility; 
using ESRI.ArcGIS.Carto; 
using ESRI.ArcGIS.Geodatabase; 
using ESRI.ArcGIS.Geometry; 
using ESRI.ArcGIS.Display;
public partial class _Default : System.Web.UI.Page 
{ 
//创建数据表，用于数据绑定 
DataTable layertable;
protected void Page_Init(object sender, EventArgs e) 
{ 
if (!Page.IsPostBack) 
{ 
layertable = new DataTable("layertable"); 
DataColumn dc1 = new DataColumn("layername"); 
DataColumn dc2 = new DataColumn("layerpath"); 
layertable.Columns.Add(dc1); 
layertable.Columns.Add(dc2); 
//读取文件（是一些基本功能） 
String rootPath = Server.MapPath("~");
System.IO.StreamReader sr = new System.IO.StreamReader(rootPath + "/layers.catalog"); 
string delimStr = "="; 
char[] delimiter = delimStr.ToCharArray(); 
string[] readparts = null; 
string readstring = null;
while (sr.Peek() != -1) 
{ 
readstring = sr.ReadLine(); 
if (!readstring.Contains("=")) 
break;
readparts = readstring.Split(delimiter); 
DataRow dr = layertable.NewRow(); 
dr[0] = readparts[0]; 
dr[1] = readparts[1]; 
layertable.Rows.Add(dr); 
} 
sr.Close(); 
} 
}
protected void Page_PreRender(object sender, EventArgs e) 
{ 
//数据绑定 
DropDownList1.DataSource = layertable; 
DropDownList1.DataTextField = "layername"; 
DropDownList1.DataValueField = "layerpath"; 
DropDownList1.DataBind();
if (!Page.IsPostBack) 
{ 
if (Session.IsNewSession) 
{ 
Session.Add("addedlayers", false); 
Session.Add("addedlayersid", null); 
//创建server上下文 
IServerContext mapContext = this.getServerContext(); 
//使用server上下文来定义地图服务 
IMapServer mapServer = mapContext.ServerObject as IMapServer; 
//获得地图服务信息 
IMapServerInfo mapInfo = mapServer.GetServerInfo(mapServer.DefaultMapName); 
//获得地图描述信息 
IMapDescription mapDesc = mapInfo.DefaultMapDescription; 
//放到session中去 
SetSessionMapDescription(mapContext, mapDesc); 
//创建地图 
CreateMapImage(mapContext, mapDesc); 
//释放调server上下文 
mapContext.ReleaseContext();
} 
else 
{ 
IServerContext mapContext = this.getServerContext(); 
mapContext = this.getServerContext();
IMapDescription mapDesc = GetSessionMapDescription(mapContext); 
UpdateDataLayers(mapContext);
CreateMapImage(mapContext, mapDesc);
RemoveLayers(mapContext); 
mapContext.ReleaseContext(); 
} 
} 
else 
{ 
//if a postback, do something here during load 
} 
}
//添加图层 
private void AddTheLayers(IServerContext in_mapcontext) 
{ 
IMapServer ms = (IMapServer)in_mapcontext.ServerObject;
IMapServerObjects2 mso = (IMapServerObjects2)ms; 
string mapname = ms.DefaultMapName; 
IMap map = mso.get_Map(mapname); 
//创建一个新的图层，和它想类似的还有IFeatureClass 
IFeatureLayer layer = (IFeatureLayer)in_mapcontext.CreateObject("esriCarto.FeatureLayer"); 
//IFeatureLayer layer = (IFeatureLayer)in_mapcontext.CreateObject("{E663A651-8AAD-11D0-BEC7-00805F7C4268}"); 
//创建一个用于打开和创建工作空间的一个工厂接口类 
//IFeatureLayer IFeatureClass IWorkspaceFactory 在AE中都有，他们用于打开和操作数据空间 
IWorkspaceFactory factory = (IWorkspaceFactory)in_mapcontext.CreateObject("esriDataSourcesFile.ShapefileWorkspaceFactory");
ListItem listitem = DropDownList1.SelectedItem; 
int lastslash = listitem.Value.LastIndexOf("/"); 
string filepath = listitem.Value.Substring(0, lastslash); 
string filename = listitem.Value.Substring(lastslash + 1);
IWorkspace ws = factory.OpenFromFile(filepath, 0); 
IFeatureWorkspace fws = (IFeatureWorkspace)ws; 
layer.FeatureClass = fws.OpenFeatureClass(filename); 
layer.Name = listitem.Text; 
//IGeoFeatureLayer是由IFeatureLayer继承而来，IFeatureLayer是由ILayer继承而来，IGeoFeatureLayer比IFeatureLayer多了标注方面的东西 
IGeoFeatureLayer iglayer = (IGeoFeatureLayer)layer; 
//IFeatureRenderer中定义了一个叫做Draw的方法，其实ArcObjects中各种各样的渲染效果就是通过这个Draw方法画出来的，因为各个渲染效果都实现了IFeatureRenderer接口。所以要实现"GroupRenderer"效果，只要实现了IFeatureRenderer接口就可以了。 
IFeatureRenderer renderer = iglayer.Renderer; 
//创建简单渲染 
ISimpleRenderer isr = (ISimpleRenderer)renderer; 
IRgbColor irgbc = (IRgbColor)in_mapcontext.CreateObject("esriDisplay.RgbColor"); 
irgbc.Red = 0; 
irgbc.Green = 0; 
irgbc.Blue = 210; 
//获得类别，各自进行设置。这里比较奇怪的是创建的ifs并没有被添加到图层中去，不是很明白，请教各位。 
ESRI.ArcGIS.Geometry.esriGeometryType featype = layer.FeatureClass.ShapeType; 
if (featype == ESRI.ArcGIS.Geometry.esriGeometryType.esriGeometryPoint) 
{ 
ISimpleMarkerSymbol ifs = (ISimpleMarkerSymbol)isr.Symbol; 
ifs.Color = (IColor)irgbc; 
} 
else if (featype == ESRI.ArcGIS.Geometry.esriGeometryType.esriGeometryPolyline) 
{ 
ISimpleLineSymbol ifs = (ISimpleLineSymbol)isr.Symbol; 
ifs.Color = (IColor)irgbc; 
} 
else if (featype == ESRI.ArcGIS.Geometry.esriGeometryType.esriGeometryPolygon) 
{ 
ISimpleFillSymbol ifs = (ISimpleFillSymbol)isr.Symbol; 
ifs.Color = (IColor)irgbc; 
} 
else 
{ 
throw new Exception("No renderer or symbol selected. Shape type undetermined."); 
} 
//增加图层 
map.AddLayer(layer); 
mso.RefreshServerObjects();
Session["addedlayersid"] = mso.get_LayerID(mapname, layer); 
}
private void CreateMapImage(IServerContext mapContext, IMapDescription md) 
{ 
//分别创建图像类别 图像描述 图像显示 
IImageType imageType; 
IImageDescription imageDesc; 
IImageDisplay imageDisp;
imageType = mapContext.CreateObject("esriCarto.ImageType") as IImageType; 
imageDesc = mapContext.CreateObject("esriCarto.ImageDescription") as ImageDescription; 
imageDisp = mapContext.CreateObject("esriCarto.ImageDisplay") as ImageDisplay; 

imageType.Format = esriImageFormat.esriImageJPG; 
imageType.ReturnType = esriImageReturnType.esriImageReturnURL;
imageDisp.Height = (int)imgOutput.Height.Value; 
imageDisp.Width = (int)imgOutput.Width.Value; 
imageDisp.DeviceResolution = 96;
imageDesc.Display = imageDisp; 
imageDesc.Type = imageType; 
//创建地图服务 
IMapServer mapServer = (IMapServer)mapContext.ServerObject;
IImageResult mapImage = mapServer.ExportMapImage(md, imageDesc); 
imgOutput.ImageUrl = mapImage.URL; 
imgOutput.Visible = true;
} 
//创建session 
private void SetSessionMapDescription(IServerContext in_mapcontext, IMapDescription in_mapdesc) 
{ 
string md = in_mapcontext.SaveObject(in_mapdesc); 
Session.Add("md", md); 
} 
//获得session 
private IMapDescription GetSessionMapDescription(IServerContext in_mapcontext) 
{ 
string stringDesc = Session["md"] as string; 
IMapDescription mapDesc = null;
if (stringDesc == null) 
{ 
IMapServer mapServer = in_mapcontext.ServerObject as IMapServer; 
IMapServerInfo mapInfo = mapServer.GetServerInfo(mapServer.DefaultMapName); 
mapDesc = mapInfo.DefaultMapDescription; 
} 
else 
{ 
mapDesc = in_mapcontext.LoadObject(stringDesc) as IMapDescription; 
}
return mapDesc; 
} 
//创建server上下文，在这个上下文中，运用IServerObjectManager对象管理其生命周期 
private IServerContext getServerContext() 
{ 
string servername = "localhost"; 
string mapserverobject = "USA_data"; 
IServerObjectManager serverManager;
if (Session["SOM"] == null) 
{ 
// *** Using Web ADF Common API 
ESRI.ArcGIS.ADF.Connection.AGS.AGSServerConnection gisconnection = new ESRI.ArcGIS.ADF.Connection.AGS.AGSServerConnection(); 
gisconnection.Host = servername; 
gisconnection.Connect();
serverManager = gisconnection.ServerObjectManager; 
Session.Add("SOM", serverManager);
} 
else 
{ 
serverManager = Session["SOM"] as IServerObjectManager; 
}
// *** Change the map server object name as needed 
IServerContext mapContext = serverManager.CreateServerContext(mapserverobject, "MapServer");
return mapContext;
}
private void RemoveLayers(IServerContext in_mapcontext) 
{ 
//判断是否添加了图层 
bool tf = (bool)Session["addedlayers"];
if (tf) 
{ 
IMapServer ms = (IMapServer)in_mapcontext.ServerObject;
IMapServerObjects mso = (IMapServerObjects)ms;
IMap map = mso.get_Map(ms.DefaultMapName); 
//通过地图服务获得图层 
ILayer layer = map.get_Layer(0);
map.DeleteLayer(layer); 
mso.RefreshServerObjects(); 
} 
}
private void UpdateDataLayers(IServerContext mapContext) 
{ 
bool tf = (bool)Session["addedlayers"];
if (tf) 
{ 
AddTheLayers(mapContext);
// Update dynamic data id, after initial addition of dynamic layer 
IMapDescription mapDesc = GetSessionMapDescription(mapContext); 
ILayerDescription newLayerDesc = mapDesc.LayerDescriptions.get_Element(0); 
newLayerDesc.ID = (int)Session["addedlayersid"]; 
SetSessionMapDescription(mapContext, mapDesc); 
} 
}
protected void btnAddLayer_Click(object sender, EventArgs e) 
{ 
Session.Add("addedlayers", true);
IServerContext mapContext = this.getServerContext();
UpdateDataLayers(mapContext);
IMapServer ms = (IMapServer)mapContext.ServerObject;
IMapServerInfo mapInfo = ms.GetServerInfo(ms.DefaultMapName);
IMapDescription NEWmapDesc = mapInfo.DefaultMapDescription;
CreateMapImage(mapContext, NEWmapDesc);
SetSessionMapDescription(mapContext, NEWmapDesc);
RemoveLayers(mapContext);
mapContext.ReleaseContext();
}
protected void btnRefresh_Click(object sender, EventArgs e) 
{
IServerContext mapContext = this.getServerContext(); 
UpdateDataLayers(mapContext);
/* Test to see actual id of dynamic layer, compare with MapDescription stored in session (also used to generate map image). 
* 
IMapServer ms = (IMapServer)mapContext.ServerObject; 
IMapServerInfo mapInfo = ms.GetServerInfo(ms.DefaultMapName); 
IMapDescription NEWmapDesc = mapInfo.DefaultMapDescription; 
ILayerDescription NEWLayerDesc = NEWmapDesc.LayerDescriptions.get_Element(0); 
*/
IMapDescription mapDesc = GetSessionMapDescription(mapContext); 
IMapArea mapArea = mapDesc.MapArea; 
//创建IMapExtent 用于描述地图的范围.放大缩小地图 
IMapExtent mapExtent = mapArea as IMapExtent; 
//创建IEnvelope，用来确定一个空间范围，可以做空间查询 
IEnvelope env = (IEnvelope)mapContext.CreateObject("esriGeometry.Envelope"); 
env.PutCoords(-120, 30, -50, 50);
mapExtent.Extent = env;
CreateMapImage(mapContext, mapDesc);
SetSessionMapDescription(mapContext, mapDesc);
RemoveLayers(mapContext);
mapContext.ReleaseContext(); 
} 
}