In MXT, geometry & style are object model.
在mxt中,几何实体和样式都是对象模型。
The follow example code demonstrate how to create a geometry , add it to map to display it:
下面的代码演示了怎样生成一个几何对象(Point),然后+到地图控件上去显示。
The code is not difficult, but I put is here only because it covers many concepts like CoordSys(&CoordSysFactory:Design Patter Concepte), TableInfo(TableInfoMemTable), Table(Column,GeometryColumn,MI Ado.net data provider MIConnection, MICommand), Feature(FeatureGeometry)
代码本身并不难,我在这里放置这段代码的原因是因为它涉及到很多概念:坐标系(坐标系工厂:设计模式概念),表格元数据:表格信息(内存表格),表格(列,集合列,MapInfo数据提供者,数据连接,命令)图元(几何图元)
I hope u can have a deeper understanting about i
希望你能有一个深刻的理解。
The code is without any comment, I think u r more clever than me.
代码没有注释,因为我认为你比我更聪明,
1
private void button1_Click(object sender, System.EventArgs e)
2
{
3
4
CoordSysFactory csf = new CoordSysFactory();
5
CoordSys coordsys = csf.CreateCoordSys("mapinfo:coordsys 1,104");
6
double x = 10,y=20;
7
8
TableInfoMemTable timt = new MapInfo.Data.TableInfoMemTable("mem");
9
10
11
12
GeometryColumn gc = new MapInfo.Data.GeometryColumn(coordsys);
13
gc.Alias = "Obj";
14
gc.DataType = MIDbType.FeatureGeometry;
15
timt.Columns.Add(gc);
16
17
Column c = new Column();
18
c.Alias = "MI_Style";
19
c.DataType = MIDbType.Style;
20
timt.Columns.Add(c);
21
Table table = MapInfo.Engine.Session.Current.Catalog.CreateTable(timt);
22
23
Geometry g = new MapInfo.Geometry.Point(coordsys,x,y);
24
FeatureGeometry fg = (FeatureGeometry)g;
25
26
SimpleVectorPointStyle svps = new SimpleVectorPointStyle(34,Color.Red,50);
27
CompositeStyle cs = new CompositeStyle(svps);
28
29
MIConnection micon = new MIConnection();
30
31
micon.Open();
32
MICommand micom = micon.CreateCommand();
33
micom.CommandText = "insert into mem values(@obj,@style)";
34
micom.Parameters.Add("@obj",MIDbType.FeatureGeometry);
35
micom.Parameters.Add("@style",MIDbType.Style);
36
micom.Parameters["@obj"].Value = g;
37
micom.Parameters["@style"].Value = cs;
38
39
micom.Prepare();
40
int n = micom.ExecuteNonQuery();
41
42
micom.Cancel();
43
micom.Dispose();
44
45
FeatureLayer fl = new FeatureLayer(table);
46
this.mapControl1.Map.Layers.Add(fl);
47
48
49
50
} Because all geometry is a object , u can create any FeatureGeometry to & add it to the map;the code is all the same except the constructor to create the geometry.
因为几何实体都是对象,所以你可以创建自己的几何实体,并+到地图上去显示它;所有的代码都是很相似,仅仅是不同类型,其构造方法不同而已。