求助。。。在Asp.net(C#)+Mapxtreme2005中怎么样增加x,y点图层

<P>我是这样写的，可是显示不出来</P>
<P>大家帮帮忙，谢谢！</P>
<P>//建立XY空间方案<BR>   MapInfo.Data.SpatialSchemaXY xy = new MapInfo.Data.SpatialSchemaXY();<BR>   xy.XColumn = "X";<BR>   xy.YColumn = "Y";<BR>   xy.NullPoint = "0.0, 0.0";<BR>   xy.StyleType = MapInfo.Data.StyleType.None;<BR>   xy.DefaultStyle = new MapInfo.Styles.CompositeStyle();<BR>   xy.CoordSys = MapInfo.Engine.Session.Current.CoordSysFactory.CreateLongLat(MapInfo.Geometry.DatumID.WGS84);</P>
<P>   //建立TableInfo   <BR>   MapInfo.Data.TableInfoServer ti=new  TableInfoServer("sourcetable");<BR>   ti.ConnectString ="Driver={SQL Server};Server=xiewei;database=MapSamples; Uid=sa;Pwd=123;QuotedID=Yes;Trusted_Connection=No;Network=DBMSSOCN;Address=PALADIN,1433;DLG=SQL_DRIVER_NOPROMPT";<BR>   ti.Query="select * from Sheet1";<BR>   ti.Toolkit=MapInfo.Data.ServerToolkit.Odbc;  <BR>   ti.CacheSettings.CacheType = CacheOption.Off;</P>
<P>   ti.SpatialSchema = xy;<BR>   MapInfo.Data.Table miCustomers = MapInfo.Engine.Session.Current.Catalog.OpenTable (ti);<BR>   bool ismap = miCustomers.IsMappable;<BR>   MapInfo.Mapping.FeatureLayer featureLayer = new MapInfo.Mapping.FeatureLayer(miCustomers,"Database","Database"); </P>
<P>   MapInfo.Mapping.Map myMap = GetMapObj();</P>
<P>   for(int i=myMap.Layers.Count-1;i>=0 ;i--)<BR>   {<BR>    myMap.Layers.RemoveAt(i);<BR>   }<BR>   <BR>   myMap.Layers.Add (featureLayer);</P>