[原创]将MO的Ellipse对象转化为Polygon对象！

<P>代码如下（直接复制到一个地图窗口下即可运行）：</P>
<P>Option Explicit</P>
<P>'//圆周率"派"值<br>Const PI As Single = 3.1415926</P>
<P>Private Sub Map1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)</P>
<P>    '//鼠标绘制圆形<br>    Dim crl As New MapObjects2.Ellipse<br>    Set crl = Map1.TrackCircle<br>    <br>    '//将圆形转化为多边形<br>    Dim pgn As New MapObjects2.Polygon<br>    Set pgn = ChangeCircleToPolygon(crl)<br>    <br>    '//闪烁多边形<br>    Map1.FlashShape pgn, 2<br>End Sub</P>
<P>'*******************************************************************************<br>'【名  称】：ChangeCircleToPolygon()<br>'【功  能】：将圆形对象转化为多边形对象<br>'【参  数】：crl  ： 圆形对象<br>'            Sect ： 转化后的多边形边数<br>'【返回值】：新的MO多边形对象<br>'******************************************************************************<br>Public Function ChangeCircleToPolygon(crl As MapObjects2.Ellipse, Optional Sect As Integer = 40) As MapObjects2.Polygon<br>    '//获得圆心<br>    Dim CPt As New MapObjects2.Point<br>    Set CPt = crl.Center<br>    <br>    '//获得圆心坐标<br>    Dim Cx As Double: Dim Cy As Double<br>    Cx = CPt.X: Cy = CPt.Y<br>    <br>    '//获得半径<br>    Dim rds As Double<br>    rds = crl.Width / 2<br>    <br>    '//获得等边多边形每一边所对应的夹角<br>    Dim cnr As Double<br>    cnr = PI * 2 / Sect<br>    <br>    '//生成新的多边形对象<br>    Dim pnt As New MapObjects2.Point: Dim pnts As New MapObjects2.Points<br>    Dim X As Double: Dim Y As Double<br>    Dim pgn As New MapObjects2.Polygon<br>    <br>    Dim i As Integer<br>    For i = 1 To Sect<br>        X = Cx + Cos(i * cnr) * rds<br>        Y = Cy + Sin(i * cnr) * rds<br>        pnt.Set X, Y<br>        pnts.Add pnt<br>    Next<br>    pgn.Parts.Add pnts<br>    <br>    Set ChangeCircleToPolygon = pgn<br>End Function<br></P>

<P>仅供参考吧，最好的办法是直接利用Buffer属性</P>
<P>dim pgn as new mapobjects2.polygon</P>
<P>set pgn = Ellipse.Buffer(0,map1.extent)</P>

<P>高啊。简单。mo对园和矩形以0为缓冲距离。将返回一个多边形对象。而且仅是原数据的拷贝</P>