MapXtreme2004代码 在地图上新增加点图元

private void Button1_Click(object sender, System.EventArgs e)
{
//在当前地图中心的X和Y坐标的二分之一处画点
Map map1=MapControl1.Map;
double x=map1.Center.x/2;
double y=map1.Center.y/2;
showPointOnSearchTableMap(x,y);
}

private void showPointOnSearchTableMap(double x, double y)
{
Map map=MapControl1.Map;
MapInfo.Data.Table table=MapInfo.Engine.Session.Current.Catalog.GetTable("temp");
CoordSys coordSys=map.GetDisplayCoordSys();

if (table==null)
{
TableInfoMemTable tableInfo=new TableInfoMemTable("temp");
tableInfo.Temporary =true;

Column column;
column=new GeometryColumn(coordSys);
column.Alias="MI_Geometry";
column.DataType =MIDbType.FeatureGeometry;
tableInfo.Columns.Add(column);

column=new Column();
column.Alias="MI_Style";
column.DataType =MIDbType.Style;
tableInfo.Columns.Add(column);

table = MapInfo.Engine.Session.Current.Catalog.CreateTable(tableInfo);
}
else
{
MIConnection conn=new MIConnection();
MICommand tempcmd=conn.CreateCommand();
tempcmd.CommandText ="delete from temp";
conn.Open();
tempcmd.ExecuteNonQuery();
conn.Close();
tempcmd.Dispose();
}

//创建点及其样式
FeatureGeometry geometry=new MapInfo.Geometry.Point (coordSys,x,y);
SimpleVectorPointStyle vStyle=new SimpleVectorPointStyle(40,System.Drawing.Color.Green,14);
//创建的点的样式、颜色和大小都在上条语句中修改
CompositeStyle cStyle=new MapInfo.Styles.CompositeStyle(vStyle);

MIConnection connection=new MIConnection();
MICommand cmd=connection.CreateCommand();
cmd.Parameters.Add("geometry",MIDbType.FeatureGeometry);
cmd.Parameters.Add("style",MIDbType.Style);
cmd.CommandText ="Insert Into temp(MI_Geometry,MI_Style) values (geometry,style)";

connection.Open();
cmd.Parameters[0].Value =geometry;
cmd.Parameters[1].Value =cStyle;
int nchanged=cmd.ExecuteNonQuery();
cmd.Dispose();

//创建图层并将其插入到当前地图的最上层
FeatureLayer fl = new FeatureLayer(table);
map.Layers.Insert(0,fl);

map.Center = new MapInfo.Geometry.DPoint(x,y);
}