form04.frm

给出了详细的vb环境下mo基本功能的代码 如图层的加载

VERSION 5.00
Object = "{9BD6A640-CE75-11D1-AF04-204C4F4F5020}#2.0#0"; "mo20.ocx"
Begin VB.Form Form04 
   Caption         =   "墨西哥地图"
   ClientHeight    =   5355
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   6765
   LinkTopic       =   "Form1"
   ScaleHeight     =   5355
   ScaleWidth      =   6765
   StartUpPosition =   2  '屏幕中心
   Begin VB.CommandButton Command1 
      Caption         =   "显示"
      Height          =   495
      Left            =   2760
      TabIndex        =   1
      Top             =   4800
      Width           =   1335
   End
   Begin MapObjects2.Map Map1 
      Height          =   4575
      Left            =   0
      TabIndex        =   0
      Top             =   0
      Width           =   6735
      _Version        =   131072
      _ExtentX        =   11880
      _ExtentY        =   8070
      _StockProps     =   225
      BackColor       =   16777215
      BorderStyle     =   1
      Contents        =   "Form04.frx":0000
   End
End
Attribute VB_Name = "Form04"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
'Xue Wei,2003/6/6
'使用ValueRenderer；

Option Explicit

Dim moRecset As MapObjects2.Recordset
Dim oRenderer As New MapObjects2.ValueMapRenderer

Private Sub Command1_Click()
  Dim strs As New MapObjects2.Strings
  Dim sFldname As String
  Dim oSym As New MapObjects2.Symbol
  Dim i As Integer
  
  '初始化
  Set moRecset = Map1.Layers(0).Records
  sFldname = "AREA"
  Do While Not moRecset.EOF
    strs.Add moRecset(sFldname).ValueAsString
    moRecset.MoveNext
  Loop
  
  '设置渲染参数；
  Set Map1.Layers(0).Renderer = oRenderer
  oRenderer.Field = sFldname
  oRenderer.ValueCount = strs.Count '- 3
  
  '设置缺省值
  oRenderer.UseDefault = True
  Set oSym = oRenderer.DefaultSymbol
  oSym.Color = moPaleYellow
  
  '开始渲染；
  For i = 0 To oRenderer.ValueCount - 1
    oRenderer.Value(i) = strs(i)
  Next i
  Map1.Refresh
  
  '清除对象，为下次点击准备；
  Set oRenderer = Nothing
  Set strs = Nothing
  Set moRecset = Nothing
End Sub

Private Sub Form_Load()
  DrawLayer   '添加一个States图层；
End Sub

Private Sub DrawLayer()
  Dim dc As New DataConnection
  Dim layer As MapLayer
  dc.Database = App.Path + "\..\" + "Mexico"
  If Not dc.Connect Then
    MsgBox "在指定的文件夹下没找到图层数据文件！"
    End
  End If
    
  Set layer = New MapLayer
  Set layer.GeoDataset = dc.FindGeoDataset("States")
  layer.Symbol.Color = moOrange
  layer.Symbol.Size = 1
  layer.Symbol.Style = 2
  layer.Symbol.OutlineColor = moBrown
  Map1.Layers.Add layer
  Map1.Refresh
End Sub