MapGIS 10 Objcet开发入门(4-6) MapGIS 10 Objects开发常见问题之显示部分动态注记

答：这个问题涉及到两个方面：动态注记与部分显示。

在 GeoMap 提供的图层对象（VectorLayer）里面都有相应的功能接口与之对应，动态注记由图层的属性 Label 提供；而实现部分显示则通过图层设置显示过滤条件，由函数 SetDispCondition 提供。示例代码如下：

//地图显示控件
MapControl mapControl1 = null;
//数据库服务器
Server srv = null;
//数据库
DataBase db = null;
//数据
SFeatureCls SFeature = null;
Map map = null;
VectorLayer layer = null;
//初始化控件
this.mapControl1 = new MapControl();
this.splitContainer1.Panel2.Controls.Add(this.mapControl1);
//打开数据源
srv = new Server();
srv.Connect("mapgislocal", "", "");
db = srv.OpenGDB("world");
//打开用于显示的简单要素类
SFeature = (SFeatureCls)db.GetXClass(XClsType.SFCls);
SFeature.Open("行政区.WP", 0);
layer = new VectorLayer(VectorLayerType.SFclsLayer);
if (SFeature != null)
layer.AttachData(SFeature);
//添加图层
map = new Map();
map.Append(layer);
//显示图层
this.mapControl1.ActiveMap = map;
SimpleLabel splbl = null;
//注记信息
LabelInfo labelInfo = null;
//注记图形信息
AnnInfo annInfo = null;
//区标注分布信息
RegionPlaceInfo regPlaceInfo = null;
splbl = new SimpleLabel();
labelInfo = new LabelInfo();
TextAnnInfo txtAnninfo = new TextAnnInfo();
regPlaceInfo = new RegionPlaceInfo();
#region 设置注记图形信息
txtAnninfo.Color = 5;
txtAnninfo.Height = 10;
txtAnninfo.Width = 10;
//间隔
txtAnninfo.Space = 2;
//压盖
txtAnninfo.Ovprnt = true;
#endregion
#region 设置注记显示参数信息
labelInfo.AnnInfo = txtAnninfo;
labelInfo.Caption = "名称";
labelInfo.IsVisible = true;
labelInfo.MaxScale = 0;
labelInfo.MinScale = 0;
#endregion
#region 区标注分布信息
//每个要素一个标注
regPlaceInfo.DuplicateType = DuplicateType.OneLabelPreFeature;
//自适应
regPlaceInfo.LimitLabelSmallRegion = true;
//最大面积
regPlaceInfo.SmallRegionMaxArea = 500;
//可标注在区外
regPlaceInfo.TryLabelOutside = true;
//区方位-水平标注
regPlaceInfo.Type = RegPlaceType.HorizationPlace;
#endregion
#region 设置简单注记
//设置属性字段*
splbl.LabelExpression = "名称";
splbl.HighlightClr = 6;
splbl.LabelGeomType = LabelGeomType.RegionGeom;
//设置区标注分布
splbl.RegPlaceInfo = regPlaceInfo;
//高亮显示未能标注的注记
splbl.HighlightLabelUnPlaced = true;
splbl.LabelUnPlaced = true;
splbl.Priority = 1;
//显示动态注记
splbl.Visible = true;
splbl.SetInfo(labelInfo);
#endregion
//初始化条件显示条件
MapGIS.GeoDataBase.QueryDef disCondition = new QueryDef();
disCondition.Filter="ID>5";
disCondition.CursorType = SetCursorType.ForwardBackward;
//设置条件显示
layer.SetDispCondition(disCondition);
//设置动态注记
layer.Label = splbl;
this.mapControl1.Refresh();

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