画几何图形为什么只能画一个？有人知道吗？

谁能告诉我画几何图形的时候,只能画一个是为什么啊!画完第一个后,再画第二个,先画的就消失了,能告诉我详细原因吗?怎么解决啊!谢谢了!<BR> <img src="images/post/smile/dvbbs/em02.gif" />

<P>当然可以绘制多个;</P>
<P>你可能绘制的是临时图层上的,每次地图刷新后就不见了;</P>
<P>最好给出你的代码,大家比较好解释</P>

<P>按照以下方式绘制，并结合你自身的代码，应该可以解决你的问题</P>
<P>Private Sub Form_Load()</P>
<P> Dim sym As MapObjects2.TrackingLayer</P>
<P>Dim  symtext As New MapObjects2.TextSymbol<BR>  Set sym = Map1.TrackingLayer<BR>  With sym <BR>    .SymbolCount = 1500<BR>    .Symbol(0).SymbolType = moPointSymbol '点样式<BR>    .Symbol(0).style = moTriangleMarker '三角形<BR>    .Symbol(0).color = moRed<BR>    .Symbol(0).Size = 4<BR>    .Symbol(1).SymbolType = moLineSymbol'线样式<BR>    .Symbol(1).style = moSolidLine'实线<BR>    .Symbol(1).color = moRed<BR>    .Symbol(1).Size = 2<BR>    .Symbol(2).SymbolType = moFillSymbol'面样式<BR>    .Symbol(2).style = moTransparentFill'透明风格<BR>    .Symbol(2).OutlineColor = moRed<BR>    .Symbol(2).Size = 2<BR>  End With<BR>  symtext.color = moRed</P>
<P>End Sub</P>

<P>Private Sub Map1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)<BR>'Toolbar1工具条<BR>Select Case True<BR>      Case Toolbar1.Buttons("Add Text").Value = 1<BR>        Dim strText As String<BR>        Dim ptText As MapObjects2.Point<BR>        strText = InputBox("输入要添加文字")<BR>        Set ptText = Map1.ToMapPoint(X, Y)<BR>        Map1.Refresh<BR>      Case Toolbar1.Buttons("Add Point").Value = 1'点<BR>        Dim pt As MapObjects2.Point<BR>        Set pt = Map1.ToMapPoint(X, Y)<BR>        sym.AddEvent pt, 0<BR>      Case Toolbar1.Buttons("Add Line").Value = 1'线<BR>        Dim line As MapObjects2.Line<BR>        Set line = Map1.TrackLine<BR>        sym.AddEvent line, 1<BR>      Case Toolbar1.Buttons("Add Rectangle").Value = 1'多边形<BR>        Dim rect As MapObjects2.Rectangle<BR>        Set rect = Map1.TrackRectangle<BR>        sym.AddEvent rect, 2<BR>      Case Toolbar1.Buttons("Add Polygon").Value = 1'矩形<BR>         Dim poly As MapObjects2.Polygon<BR>         Set poly = Map1.TrackPolygon<BR>        sym.AddEvent poly, 2<BR>      Case Toolbar1.Buttons("Add Ellipse").Value = 1'圆形<BR>         Dim cirG As MapObjects2.Ellipse<BR>        Set cir = Map1.TrackCircle<BR>         sym.AddEvent cir, 2<BR>    End Select<BR>End Sub<BR></P>
<img src="images/post/smile/dvbbs/em07.gif" />

感谢楼上的两位！问题解决！正如总统所说！我画在了临时图层上了！<img src="images/post/smile/dvbbs/em02.gif" />

<P>动态跟踪层上画后，只有程序退出后才会消失，和你刷新无关</P>
<P>如果你想把所绘制的要素保存需要执行edit功能，具体操作请看帮助或M我哈</P><img src="images/post/smile/dvbbs/em08.gif" /><img src="images/post/smile/dvbbs/em08.gif" /><img src="images/post/smile/dvbbs/em08.gif" /><img src="images/post/smile/dvbbs/em08.gif" /><img src="images/post/smile/dvbbs/em08.gif" />