[请教]VB+MO怎样用legend1的MouseDown事件来在Combo1控件中显示相应图层的字段

我在做毕业设计，我是MO 新手

本来我在我手头有一个同学在网上收来的源码

Private Sub legend1_LayerDblClick(Index As Integer) '图例 双击将图层的的字段名加到列表框list1中

Dim ofiled As MapObjects2.Field

Combo1.Clear

For Each ofiled In Map1.Layers(Index).Records.Fields

Combo1.AddItem ofiled.Name

Next

'begin with id num

Combo1.ListIndex = 0

End Sub

是双击事件，可我早已设定了双击legend1控件显示设计图层颜色对话框，就矛盾了！

我把上面得代码加入legend1_MouseDown事件中想碰碰运气，但开始还真管用，单击激活图层就在Combo1中显示了各层相应字段，但点击空白处就出现了错误！！！！！！！！有哪位高手能解决这个问题，能告诉我怎样改进，或把代码贴上来，先谢谢各位了！

双击进行图层编辑：

Private Sub legend1_LayerDblClick(Index As Integer)
 Set ActiveLayer = Map1.Layers(Index)
 If ActiveLayer.LayerType = moImageLayer Then
   MsgBox "不能为该类图层建立相应属性！"
   Exit Sub
 End If
 frmedit.Show

End Sub

以下是frmedit的代码：

Option Explicit

Dim strMarkerStyle(3) As String
Dim strLineStyle(4) As String
Dim strFillStyle(10) As String
Dim lyr As MapObjects2.MapLayer
Dim a As Integer

Private Sub cmdApply_Click()
Call ApplySymbol
lyr.Name = txtLayerName.text
Form1.legend1.LoadLegend
Form1.Map1.Refresh
End Sub

Private Sub cmdCancel_Click()
Unload Form5
End Sub

Private Sub cmdOk_Click()
Call cmdApply_Click
Unload Form5
End Sub

Private Sub Form_Load()
 Set lyr = Form1.ActiveLayer
 txtLayerName = lyr.Name
 strMarkerStyle(0) = "圆形"
 strMarkerStyle(1) = "正方形"
 strMarkerStyle(2) = "三角形"
 strMarkerStyle(3) = "十字"
 strLineStyle(0) = "长线"
 strLineStyle(1) = "短线"
 strLineStyle(2) = "点线"
 strLineStyle(3) = "点划线1"
 strLineStyle(4) = "点划线2"
 strFillStyle(0) = "充实"
 strFillStyle(1) = "透明"
 strFillStyle(2) = "横线"
 strFillStyle(3) = "竖线"
 strFillStyle(4) = "上斜线"
 strFillStyle(5) = "下斜线"
 strFillStyle(6) = "正十字"
 strFillStyle(7) = "斜十字"
 strFillStyle(8) = "亮格网"
 strFillStyle(9) = "格网"
 strFillStyle(10) = "暗格网"
 
Call LoadSingleSymbol
End Sub

Private Sub ApplySymbol()

 Dim sym As MapObjects2.Symbol
 Set sym = lyr.Symbol
 lyr.Name = txtLayerName.text
 Set lyr.Renderer = Nothing
 
 Select Case lyr.shapeType
   Case moShapeTypePoint
     sym.Color = picSSP(0).BackColor
     sym.Style = cboSSP.ListIndex
     
     If IsNumeric(txtSSP.text) Then
       sym.Size = txtSSP.text
      Else
       sym.Size = 5
     End If
   Case moShapeTypeMultipoint
     sym.Color = picSSP(0).BackColor
     sym.Style = cboSSP.ListIndex
     
     If IsNumeric(txtSSP.text) Then
       sym.Size = txtSSP.text
      Else
       sym.Size = 5
     End If
   Case moLine
     sym.Color = picSSP(0).BackColor
     sym.Style = cboSSP.ListIndex
     If IsNumeric(txtSSP.text) Then
       sym.Size = txtSSP.text
      Else
       sym.Size = 1
     End If
   Case moPolygon
     sym.Color = picSSP(0).BackColor
     sym.OutlineColor = picSSP(1).BackColor
     sym.Style = cboSSP.ListIndex
     If IsNumeric(txtSSP.text) Then
       sym.Size = txtSSP.text
      Else
       sym.Size = 1
     End If
     Select Case chkSSP.Value
       Case 1
         lyr.Symbol.Outline = True
       Case 0
         lyr.Symbol.OutlineColor = lyr.Symbol.Color
         lyr.Symbol.Outline = False
     End Select
 End Select
End Sub

Private Sub LoadSingleSymbol()

 Dim i As Integer
 Dim fnt As New StdFont
 
 cboSSP.Clear
 Select Case lyr.shapeType
   Case moShapeTypePoint
     chkSSP.Visible = False
     picSSP(1).Visible = False
     lblSSP(2).Visible = False
     
     txtSSP.text = lyr.Symbol.Size
     lblSSP(3).Caption = "颜色："
     lblSSP(1).Caption = "大小："
     For i = 0 To 3
       cboSSP.AddItem strMarkerStyle(i)
     Next
     picSSP(0).BackColor = lyr.Symbol.Color
     cboSSP.text = strMarkerStyle(lyr.Symbol.Style)
     cboSSP.ListIndex = lyr.Symbol.Style
    Case moShapeTypeMultipoint
     chkSSP.Visible = False
     picSSP(1).Visible = False
     lblSSP(2).Visible = False
     
     txtSSP.text = lyr.Symbol.Size
     lblSSP(1).Caption = "大小："
     For i = 0 To 4
       cboSSP.AddItem strMarkerStyle(i)
     Next
     picSSP(0).BackColor = lyr.Symbol.Color
     cboSSP.text = strMarkerStyle(lyr.Symbol.Style)
     cboSSP.ListIndex = lyr.Symbol.Style
   Case moShapeTypeLine
     chkSSP.Visible = False
     picSSP(1).Visible = False
     lblSSP(2).Visible = False
     
     txtSSP.text = lyr.Symbol.Size
     lblSSP(1).Caption = "线宽："
     For i = 0 To 4
       cboSSP.AddItem strLineStyle(i)
     Next
     picSSP(0).BackColor = lyr.Symbol.Color
     cboSSP.text = strLineStyle(lyr.Symbol.Style)
     cboSSP.ListIndex = lyr.Symbol.Style
   Case moShapeTypePolygon
     chkSSP.Visible = True
     picSSP(1).Visible = True
     lblSSP(2).Visible = True
     
      If lyr.Symbol.Size = 0 Then
       txtSSP.text = 1
      Else
       txtSSP.text = lyr.Symbol.Size
     End If
     For i = 0 To 10
       cboSSP.AddItem strFillStyle(i)
     Next
     picSSP(0).BackColor = lyr.Symbol.Color
     picSSP(1).BackColor = lyr.Symbol.OutlineColor
     cboSSP.text = strFillStyle(lyr.Symbol.Style)
     cboSSP.ListIndex = lyr.Symbol.Style
     Select Case lyr.Symbol.Outline
       Case True: chkSSP.Value = 1
       Case False: chkSSP.Value = 0
     End Select
 End Select

End Sub

Private Sub picSSP_Click(Index As Integer)
 dlgColor.ShowColor
 picSSP(Index).BackColor = dlgColor.Color
End Sub

太谢谢楼上！你的代码对我来说绝对是意外的惊喜，本来我以用CommonDialog1做出了双击Legend1弹出颜色对话框的功能但我也不太满意，你的代码我会试试的！谢谢了！但我想要能单击激活图层在Combo1中显示相应激活图层字段的功能！如果有谁能解决这个问题的话我同样感激不尽！