ArcGis Server开发Web GIS新手体验（四）
接（三）
这一节主要贴代码算了，通过代码看一下一些简单功能的实现。偶快要放假了，静不下心来写了，写得也不好。说不定贴代码效果更好。
１、获取所有图层
ESRI.ArcGIS.Server.WebControls.WebMap webmap= Map1.CreateWebMap();
try
{
ESRI.ArcGIS.Carto.IMapDescription descr = webmap.MapDescription;
ddlLayers.Items.Clear();
int id;
for (int i=0;i<= descr.LayerDescriptions.Count-1;i++)
{
id = descr.LayerDescriptions.get_Element(i).ID;
ddlLayers.Items.Add(id.ToString() + "," + webmap.LayerNameFromID(id)); //ddlLayers是一个DropDownList控件
}
if (ddlLayers.Items.Count>0)
{
ddlLayers.SelectedIndex=0;
}
}
finally
{
webmap.Dispose();
}
try
{
ESRI.ArcGIS.Carto.IMapDescription descr = webmap.MapDescription;
ddlLayers.Items.Clear();
int id;
for (int i=0;i<= descr.LayerDescriptions.Count-1;i++)
{
id = descr.LayerDescriptions.get_Element(i).ID;
ddlLayers.Items.Add(id.ToString() + "," + webmap.LayerNameFromID(id)); //ddlLayers是一个DropDownList控件
}
if (ddlLayers.Items.Count>0)
{
ddlLayers.SelectedIndex=0;
}
}
finally
{
webmap.Dispose();
}
２、通过图层的ID获取图层对象
private IFeatureLayer GetFeatureLayer(int lyid)
{
WebMap webmap = Map1.CreateWebMap();
try
{
ILayer layer = (webmap.MapServer as IMapServerObjects).get_Layer(webmap.DataFrame,lyid);
if (layer==null)
return null;
else
{
return (layer as IFeatureLayer);
}
}
finally
{
webmap.Dispose();
}
}
{
WebMap webmap = Map1.CreateWebMap();
try
{
ILayer layer = (webmap.MapServer as IMapServerObjects).get_Layer(webmap.DataFrame,lyid);
if (layer==null)
return null;
else
{
return (layer as IFeatureLayer);
}
}
finally
{
webmap.Dispose();
}
}
３、新建一个多边形
private void Map1_Polygon(object sender, ESRI.ArcGIS.Server.WebControls.PolygonEventArgs args)
{
if (args.ToolName == "newpolygon")
{
IFeatureLayer flayer = GetCurFeatureLayer(); //获取当前活动图层了函数，这里就不贴了，就是调用GetFeatureLayer(int lyid)函数 if (flayer == null) return; if (flayer.FeatureClass.ShapeType != ESRI.ArcGIS.Geometry.esriGeometryType.esriGeometryPolygon) { string sc; sc = "<script language=javascript>alert('当前图层何类型不对！')</script>"; Page.RegisterClientScriptBlock("ShapeTypeError",sc); return;
} //生成多边形 ESRI.ArcGIS.Server.IServerContext context; ESRI.ArcGIS.Server.WebControls.WebMap webmap = Map1.CreateWebMap(); webmap.ManageLifetime(flayer); context = webmap.ServerContext; ESRI.ArcGIS.Geometry.IPolygon poly = context.CreateObject("esriGeometry.Polygon") as ESRI.ArcGIS.Geometry.IPolygon; //'new ag.PolygonClass(); webmap.ManageLifetime(poly); ESRI.ArcGIS.Geometry.IPoint pt; ESRI.ArcGIS.Geometry.IGeometryCollection ringcol = context.CreateObject("esriGeometry.Polygon") as ESRI.ArcGIS.Geometry.IGeometryCollection;// new PolygonClass(); webmap.ManageLifetime(ringcol); ESRI.ArcGIS.Geometry.IPointCollection ptcol =context.CreateObject("esriGeometry.Ring") as ESRI.ArcGIS.Geometry.IPointCollection;// new RingClass(); webmap.ManageLifetime(ptcol); object obj=Type.Missing; for (int i=0;i<=args.Vectors.Length-1;i++) { pt = webmap.ToMapPoint(args.Vectors[i].X,args.Vectors[i].Y); ptcol.AddPoint(pt,ref obj,ref obj); } ringcol.AddGeometry(ptcol as IGeometry,ref obj,ref obj); poly = ringcol as IPolygon; //将多边形写入到图层中 ESRI.ArcGIS.Geodatabase.IFeature feature = flayer.FeatureClass.CreateFeature(); feature.Shape = poly as IGeometry; feature.Store(); webmap.Refresh(); webmap.Dispose(); }
}
４、矩形选择，获得选择集，并在地图上显示选中的对象。（这个功能花费了偶一天多的时间。）
private void Map1_DragRectangle(object sender, ESRI.ArcGIS.Server.WebControls.ToolEventArgs args) { string strTool = args.ToolName.ToLower(); if (strTool=="rectsel") { //取得当前层 if (ddlLayers.SelectedValue=="") return; IFeatureLayer flayer = GetCurFeatureLayer(); if (flayer == null) return; //获得选择集 int t1=Environment.TickCount; ESRI.ArcGIS.Server.WebControls.WebMap webmap = Map1.CreateWebMap(); ESRI.ArcGIS.Server.IServerContext ctx = webmap.ServerContext; webmap.ManageLifetime(ctx); ESRI.ArcGIS.Geodatabase.IWorkspace ws = (flayer.FeatureClass as ESRI.ArcGIS.Geodatabase.IDataset).Workspace; ESRI.ArcGIS.Geometry.IEnvelope env = ctx.CreateObject("esriGeometry.Envelope") as ESRI.ArcGIS.Geometry.IEnvelope; webmap.ManageLifetime(ws); webmap.ManageLifetime(env); IPoint pt = webmap.ToMapPoint(Convert.ToInt32(Request.Params.Get("maxx")),Convert.ToInt32(Request.Params.Get("maxy"))); env.XMax = pt.X; env.YMin = pt.Y; pt = webmap.ToMapPoint(Convert.ToInt32(Request.Params.Get("minx")),Convert.ToInt32(Request.Params.Get("miny"))); env.XMin= pt.X; env.YMax = pt.Y; ESRI.ArcGIS.Geodatabase.ISpatialFilter filter = ctx.CreateObject("esriGeodatabase.SpatialFilter") as ESRI.ArcGIS.Geodatabase.ISpatialFilter; webmap.ManageLifetime(filter); filter.SpatialRel = ESRI.ArcGIS.Geodatabase.esriSpatialRelEnum.esriSpatialRelIntersects; filter.Geometry = env as ESRI.ArcGIS.Geometry.IGeometry; filter.GeometryField = flayer.FeatureClass.ShapeFieldName; ESRI.ArcGIS.Geodatabase.ISelectionSet sset = flayer.FeatureClass.Select(filter,ESRI.ArcGIS.Geodatabase.esriSelectionType.esriSelectionTypeSnapshot,ESRI.ArcGIS.Geodatabase.esriSelectionOption.esriSelectionOptionNormal,ws); int t2=Environment.TickCount; int t3=t2-t1; //t3是查询响应的时间，可以用来测试一下性能，呵呵 //显示选择集 int id; ESRI.ArcGIS.Geodatabase.IEnumIDs ids; ids = sset.IDs; webmap.ManageLifetime(ids); ids.Reset(); ESRI.ArcGIS.Geodatabase.IFIDSet fidset = ctx.CreateObject("esriGeodatabase.FIDSet") as ESRI.ArcGIS.Geodatabase.IFIDSet; id = ids.Next(); while (id>=0) { fidset.Add(id); id =ids.Next(); } IMapDescription desc = webmap.MapDescription as IMapDescription; webmap.ManageLifetime(desc); ILayerDescription ldesc = desc.LayerDescriptions.get_Element(flyid); webmap.ManageLifetime(ldesc); ldesc.SelectionFeatures = fidset; //将选择信息保存在session中 Session["selection"] = sset; Session["layerid"] = flyid; webmap.Refresh(); webmap.Dispose(); } }
５、删除选中的对象
private void DeleteSel() { if (Session["layerid"]==null) return; if (Session["selection"] == null) return; int layerid = (int)Session["layerid"]; if (layerid == -1) return; ESRI.ArcGIS.Geodatabase.ISelectionSet sset = Session["selection"] as ESRI.ArcGIS.Geodatabase.ISelectionSet; if (sset == null) return; WebMap webmap = Map1.CreateWebMap(); IFeatureLayer layer = GetFeatureLayer(layerid); if (layer==null) return; webmap.ManageLifetime(layer); webmap.ManageLifetime(sset); ESRI.ArcGIS.Geodatabase.IEnumIDs ids = sset.IDs; webmap.ManageLifetime(ids); ids.Reset(); int id; id = ids.Next(); ESRI.ArcGIS.Geodatabase.IFeature feature; ESRI.ArcGIS.Server.IServerContext ctx = webmap.ServerContext; webmap.ManageLifetime(ctx); //将selectionset转化为featurecursor对象 ESRI.ArcGIS.Geodatabase.IFeatureCursor fcursor; ESRI.ArcGIS.Geodatabase.ICursor cursor; sset.Search(null,false,out cursor); fcursor = cursor as ESRI.ArcGIS.Geodatabase.IFeatureCursor; ESRI.ArcGIS.esriSystem.ISet pDeleteSet = ctx.CreateObject("esriSystem.Set") as ESRI.ArcGIS.esriSystem.Set; webmap.ManageLifetime(pDeleteSet); //设置ISet对象 feature = fcursor.NextFeature(); while (feature != null) { pDeleteSet.Add(feature); feature = fcursor.NextFeature(); } ESRI.ArcGIS.Geodatabase.IFeatureEdit fedit; pDeleteSet.Reset(); fedit = pDeleteSet.Next() as ESRI.ArcGIS.Geodatabase.IFeatureEdit; while (fedit != null) { fedit.DeleteSet(pDeleteSet); fedit = pDeleteSet.Next() as ESRI.ArcGIS.Geodatabase.IFeatureEdit; } Session.Remove("layerid"); Session.Remove("selection"); webmap.Refresh(); webmap.Dispose(); }
