关于如何再mo中实现切图的功能

<P>用mo实现如下功能：</P>
<P>在有很多图层的图中，随意画一个区域，可以将这个区域的图（全部图层）单独提取出来或者能导出，这样再次导入就可以看到所切区域的图。</P>
<P>大家能否提供一些思路参考？有例子就更好了！多谢</P>

<P>用鼠标选择一个区域，然后输出到文件中，控件不写出了，自己看看吧，vb+mo2。1</P><P>Option Explicit
Private m_recsSelected As MapObjects2.Recordset
Private sym As MapObjects2.Symbol</P><P>Private Sub Command1_Click()</P><P>On Error GoTo LayerLoadError</P><P>Dim dc As New MapObjects2.DataConnection
Dim mlyr As New MapObjects2.MapLayer</P><P>'User loads shapefile into map using CommonDialog.ShowOpen
Map1.Layers.Clear
cd.Filter = "Shapefiles (*.shp)|*.shp"
cd.ShowOpen
dc.Database = CurDir
dc.Connect
Set mlyr.GeoDataset = dc.FindGeoDataset(cd.FileTitle)
mlyr.Symbol.Color = moPaleYellow
Map1.Layers.Add mlyr</P><P>LayerLoadError:
End Sub</P><P>Private Sub Command2_Click()</P><P>Dim dc As New MapObjects2.DataConnection
Dim mlyr As New MapObjects2.MapLayer</P><P>If Not m_recsSelected Is Nothing Then
  If Map1.Layers.Count > 1 Then Map1.Layers.Remove 0
  cd.ShowSave
  m_recsSelected.Export cd.FileName
  dc.Database = CurDir
  dc.Connect
  Set mlyr.GeoDataset = dc.FindGeoDataset(cd.FileTitle)
  mlyr.Symbol.Color = moRed
  Set m_recsSelected = Nothing
  Map1.Layers.Add mlyr
End If
  
End Sub</P><P>Private Sub Form_Load()</P><P>Set sym = New MapObjects2.Symbol
With sym
.SymbolType = moFillSymbol
.Color = moGreen
End With</P><P>End Sub</P><P>Private Sub Map1_AfterTrackingLayerDraw(ByVal hDC As stdole.OLE_HANDLE)</P><P>If Not m_recsSelected Is Nothing Then
  Map1.DrawShape m_recsSelected, sym
End If</P><P>End Sub</P><P>Private Sub Map1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)</P><P>Dim rect As MapObjects2.Rectangle</P><P>Set rect = Map1.TrackRectangle
Set m_recsSelected = Map1.Layers(Map1.Layers.Count - 1).SearchShape(rect, moAreaIntersect, "")
Map1.Refresh</P><P>End Sub
</P>

多谢斑竹！

<img src="images/post/smile/dvbbs/em01.gif" /><img src="images/post/smile/dvbbs/em01.gif" /><img src="images/post/smile/dvbbs/em01.gif" />

<img src="images/post/smile/dvbbs/em01.gif" /><img src="images/post/smile/dvbbs/em01.gif" />

<P>我建议用个对话框显示    用树控件显示查询结果，右键点击弹出菜单选择在列表框中显示当前记录的各属性值。</P>