[原创]MapXtreme实用技巧与源码10例
1 设置图层可选状态
/// <summary>
/// 改变层的可选择状态/// </summary>/// <param name="selectableStatus"></param>
/// <returns></returns>
public bool LayerSelectableStatusUpdate(string tableAlias,bool selectableStatus){
if(mapControl1.Map.Layers[tableAlias]==null) return false; MapInfo.Mapping.LayerHelper.SetSelectable(mapControl1.Map.Layers[tableAlias],selectableStatus); return true;} 2 设置层的可用状态
/// <summary>/// 改变层的可用状态为status/// </summary>/// <param name="layerName"></param>/// <param name="status"></param>public void LayerEnableStatusUpdate(string layerName,bool status){ if(mapControl1.Map.Layers[layerName]!=null && mapControl1.Map.Layers[layerName].Enabled!=status)
{
mapControl1.Map.Layers[layerName].Enabled=status;
}} 3 层居中，看全图
/// <summary>/// 使指定层全部呈现在地图的可见范围中/// </summary>/// <param name="tableAlias">层别名</param>public void LayerCenter(string layerName){ MapInfo.Data.Table[] tables=new MapInfo.Data.Table[1]; tables[0] = MapInfo.Engine.Session.Current.Catalog.GetTable(layerName); if(tables[0]==null) return; if(mapControl1.Map.Layers[layerName]==null) return; if(mapControl1.Map.Layers[layerName].Enabled == false) mapControl1.Map.Layers[layerName].Enabled = true; MapInfo.Mapping.IMapLayerFilter iMapLayerFilter = MapInfo.Mapping.MapLayerFilterFactory.FilterByTable(tables); MapInfo.Mapping.MapLayerEnumerator mapLayerEnumerator = mapControl1.Map.Layers.GetMapLayerEnumerator(iMapLayerFilter); mapControl1.Map.SetView(mapLayerEnumerator); OnFeatureUnclick();}
4 放大缩小地图
/// <summary>/// 放大地图/// </summary>/// <param name="times">放大倍数，有效值1－10</param>public void ZoomIn(uint times){ if(times<1 || times>10) return; MapInfo.Geometry.Distance previousZoom=this.mapControl1.Map.Zoom; mapControl1.Map.Zoom=new MapInfo.Geometry.Distance(previousZoom.Value/(2*times),previousZoom.Unit);}/// <summary>/// 缩小地图/// </summary>/// <param name="times">缩小倍数,有效值1－10</param>public void ZoomOut(uint times){ if(times<1 || times>10) return; MapInfo.Geometry.Distance previousZoom=this.mapControl1.Map.Zoom; mapControl1.Map.Zoom=new MapInfo.Geometry.Distance(previousZoom.Value*(2*times),previousZoom.Unit);}
5 移动层的顺序
mapControl1.Map.Layers.Move(index1,index2);
6 图元/图层透明
/// <summary>/// 设置层的透明与否/// </summary>/// <param name="layerName">层名</param>/// <param name="opaqueType">不透明类型 ALL 全部不透明 BORDER 只有边界不透明（内部透明） NONE 全部透明</param>/// <param name="borderColor">如果是边界不透明，此处设置边界颜色</param>public void LayerTransparent(string layerName,OpaqueType opaqueType,System.Drawing.Color borderColor){ MapInfo.Styles.CompositeStyle compositeStyle = GetOpaqueStyle(opaqueType,borderColor); //创建连接和命令来更新table中的数据 MapInfo.Data.MIConnection connection=new MapInfo.Data.MIConnection(); connection.Open(); MapInfo.Data.MICommand command=connection.CreateCommand(); command.CommandText = "update " + layerName + " set obj=obj,MI_Style=@style"; command.Parameters.Add("@style",compositeStyle); command.Prepare(); command.ExecuteNonQuery(); //关闭连接 command.Cancel(); command.Dispose(); connection.Close(); connection.Dispose();}/// <summary>/// 创建style/// </summary>/// <param name="opaqueType">不透明类型：ALL全部不透明（白色实心）；BORDER边界不透明（填充部分透明）；NONE全透明</param>/// <param name="borderColor">如果opaqueType=BORDER，此处设定边界颜色</param>/// <returns>组合style</returns>private MapInfo.Styles.CompositeStyle GetOpaqueStyle(OpaqueType opaqueType,System.Drawing.Color borderColor){ MapInfo.Styles.SimpleInterior simpleInterior; if(opaqueType==OpaqueType.ALL) simpleInterior= new MapInfo.Styles.SimpleInterior(); //缺省构造函数是白色实心 else simpleInterior= new MapInfo.Styles.SimpleInterior(1); //0是线透明，1是面透明 MapInfo.Styles.LineWidth lineWidth = new MapInfo.Styles.LineWidth(1,MapInfo.Styles.LineWidthUnit.Point); MapInfo.Styles.SimpleLineStyle simpleLineStyle; if(opaqueType==OpaqueType.ALL) simpleLineStyle = new MapInfo.Styles.SimpleLineStyle(lineWidth); else if(opaqueType==OpaqueType.BORDER) simpleLineStyle = new MapInfo.Styles.SimpleLineStyle(lineWidth,2,borderColor); //2表示填充透明，即能够显示轮廓 else simpleLineStyle = new MapInfo.Styles.SimpleLineStyle(lineWidth,0); //0表示全部透明，即连轮廓都看不到 MapInfo.Styles.AreaStyle areaStyle = new MapInfo.Styles.AreaStyle(simpleLineStyle,simpleInterior); MapInfo.Styles.CompositeStyle compositeStyle = new MapInfo.Styles.CompositeStyle(areaStyle,null,null,null); return compositeStyle;}
7 选择全部图元
MapInfo.Engine.Session.Current.Catalog.Search( table, MapInfo.Data.SearchInfoFactory.SearchAll(), MapInfo.Engine.Session.Current.Selections.DefaultSelection, MapInfo.Data.ResultSetCombineMode.Replace);
8 设置坐标系
缺省情况下，MapXtreme使用的CoordSys是经纬度投影（LongLat）和WGS84基准面。我想修改投影类型为 CoordSysType.TransverseMercator ，基准面为DatumID.Pulkovo1942
MapInfo.Geometry.CoordSysFactory coordSysFactory=MapInfo.Engine.Session.Current.CoordSysFactory;
mapControl1.Map.SetDisplayCoordSys(coordSysFactory.CreateCoordSys("mapinfo:coordsys 8,1001,7,117,0,1,20500000,0"));
coordSysFactory.CreateCoordSys("mapinfo:coordsys 8,1001,7,117,0,1,20500000,0") 默认的原点是（B=0,L=117）,如果要把原点设在(23,117)应该怎么写这个字符串呢？
coordSysFactory.CreateCoordSys("mapinfo:coordsys 8,1001,7,114,23,1,20500000,25000000")
9 保存新画的层为tab文件
下面的源码是新建一个永久表，然后在表中添加feature，然后保存为硬盘上的tab文件。
private MapInfo.Data.Table CreateNewMapDataTable(string tableName) { //以下代码是建立永久表 MapInfo.Data.TableInfoNative tableInfoNative=newMapInfo.Data.TableInfoNative(tableName); tableInfoNative.TablePath=@"D:\DATA\"+tableName+".TAB"; tableInfoNative.Columns.Add(MapInfo.Data.ColumnFactory.CreateIntColumn("ID")); tableInfoNative.Columns.Add(MapInfo.Data.ColumnFactory.CreateStyleColumn()); MapInfo.Geometry.CoordSys coordSys =mapControl1.Map.GetDisplayCoordSys(); tableInfoNative.Columns.Add(MapInfo.Data.ColumnFactory.CreateFeatureGeometryColumn(coordSys)); MapInfo.Data.Table table =MapInfo.Engine.Session.Current.Catalog.CreateTable(tableInfoNative); //以下代码是建立临时表// MapInfo.Data.TableInfo tableInfo =MapInfo.Data.TableInfoFactory.CreateTemp(tableName); // tableInfo.Columns.Add(MapInfo.Data.ColumnFactory.CreateIntColumn("ID"));// MapInfo.Data.Table table =MapInfo.Engine.Session.Current.Catalog.CreateTable(tableInfo); MapInfo.Mapping.FeatureLayer featureLayer = newMapInfo.Mapping.FeatureLayer(table); this.mapControl1.Map.Layers.Add(featureLayer); return table; } private void AddFeaturesAndSave() { MapInfo.Styles.SimpleLineStyle simpleLineStyle = newMapInfo.Styles.SimpleLineStyle(new MapInfo.Styles.LineWidth(1,MapInfo.Styles.LineWidthUnit.Point)); MapInfo.Styles.CompositeStyle compositeStyle = newMapInfo.Styles.CompositeStyle(null,simpleLineStyle, null, null); MapInfo.Geometry.CoordSys coordSys =mapControl1.Map.GetDisplayCoordSys(); MapInfo.Data.Table table = CreateNewMapDataTable("NewTable"); MapInfo.Data.TableInfo tableInfo = table.TableInfo; while(……) { MapInfo.Data.Feature feature = newMapInfo.Data.Feature(tableInfo.Columns); feature.Geometry = …… feature.Style = …… feature["ID"] = …… table.InsertFeature(feature); } tableInfo.WriteTabFile(); //保存为.tab文件 mapControl1.Refresh(); }10 计算缩放比例
/// <summary>/// 重画控件时计算缩放比例/// </summary>/// <param name="sender"></param>/// <param name="e"></param>protected void mapControl1_Paint(object sender,PaintEventArgs e){ MapInfo.Geometry.Distance zoomDistance=this.mapControl1.Map.Zoom; double zoom=Convert.ToDouble(Convert.ToInt32(zoomDistance.Value*16.09))/10; this.statusBar1.Text="缩放比例："+zoom.ToString()+" 千米";}
