form01.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 Form01 
   Caption         =   "世界地图"
   ClientHeight    =   4260
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   6465
   LinkTopic       =   "Form1"
   ScaleHeight     =   4260
   ScaleWidth      =   6465
   StartUpPosition =   2  '屏幕中心
   Begin VB.ListBox List1 
      Height          =   2040
      Left            =   4680
      TabIndex        =   3
      Top             =   360
      Width           =   1575
   End
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   495
      Left            =   4800
      TabIndex        =   2
      Top             =   2760
      Width           =   1335
   End
   Begin MapObjects2.Map Map1 
      Height          =   3375
      Left            =   120
      TabIndex        =   0
      Top             =   120
      Width           =   4335
      _Version        =   131072
      _ExtentX        =   7646
      _ExtentY        =   5953
      _StockProps     =   225
      BackColor       =   16777215
      BorderStyle     =   1
      Contents        =   "Form01.frx":0000
   End
   Begin VB.Label Label1 
      Caption         =   "Label1"
      Height          =   255
      Left            =   1560
      TabIndex        =   1
      Top             =   3720
      Width           =   3735
   End
End
Attribute VB_Name = "Form01"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
'Xue Wei,2003/6/10
'设置Unit演示；

Option Explicit
Dim theUnit As New MapObjects2.Unit

Private Sub Command1_Click()
  Label1.Caption = "图层的单位：" & theUnit.Name
End Sub

Private Sub Form_Load()
  Dim unitObjs As New MapObjects2.Strings
  Dim i As Integer
    
  '加载世界地图中的Country图层；
  DrawLayer
  
  '得到所有Unit常数名的集合；
  unitObjs.PopulateWithUnits
  
  '找到单位变量
  With Map1.Layers(0).CoordinateSystem
    If .IsProjected Then
      Set theUnit = .GeoCoordSys.Unit
    Else
      Set theUnit = .Unit
    End If
  End With
    
  '给List1赋值；
  For i = 0 To unitObjs.Count - 1
    List1.AddItem unitObjs(i) 'theUnit.Name
  Next i
  Command1.Caption = "显示"
  Label1.Caption = "点击“显示”显示单位。"
End Sub

Private Sub List1_Click()
  Dim Str1 As String
  Str1 = List1.List(List1.ListIndex)
  theUnit.Type = Int(stripProjection(Str1))
End Sub

Private Function stripProjection(theProjection As String) As Double
  Dim openB As Integer
  openB = InStr(theProjection, "[")
  stripProjection = CDbl(Left(Right(theProjection, Len(theProjection) - openB) _
  , Len(theProjection) - openB - 1))
End Function

Sub DrawLayer()
  Dim dc As New DataConnection
  Dim layer As MapLayer
  
  dc.Database = App.Path + "\..\" + "world"
  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("country")
  layer.Symbol.Color = moLimeGreen
  Map1.Layers.Add layer
End Sub