form08.frm

一个关于基于MO编程的参考资料希望对大家的交流和学习有帮助

VERSION 5.00
Object = "{9BD6A640-CE75-11D1-AF04-204C4F4F5020}#2.0#0"; "mo20.ocx"
Begin VB.Form Form08 
   Caption         =   "Form"
   ClientHeight    =   6195
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   6975
   LinkTopic       =   "Form1"
   ScaleHeight     =   6195
   ScaleWidth      =   6975
   StartUpPosition =   3  '窗口缺省
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   495
      Left            =   2760
      TabIndex        =   1
      Top             =   5520
      Width           =   1335
   End
   Begin MapObjects2.Map Map1 
      Height          =   4815
      Left            =   0
      TabIndex        =   0
      Top             =   0
      Width           =   6975
      _Version        =   131072
      _ExtentX        =   12303
      _ExtentY        =   8493
      _StockProps     =   225
      BackColor       =   16777215
      BorderStyle     =   1
      Contents        =   "Form08.frx":0000
   End
   Begin VB.Label Label1 
      Caption         =   "Label1"
      Height          =   375
      Left            =   1080
      TabIndex        =   2
      Top             =   4920
      Width           =   4815
   End
End
Attribute VB_Name = "Form08"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
'Xuewei,2003/6/14
'用Export方法产生prj文件；

Option Explicit
Dim dc As New DataConnection

Private Sub Command1_Click()
  Dim PCS As New MapObjects2.ProjCoordSys
  Dim Layer1 As MapObjects2.MapLayer
  Dim Str1 As String
  
  Set Layer1 = Map1.Layers("states1")
  PCS.Type = 54019
  With Layer1
    Str1 = dc.Database + "\states1.prj"
    .CoordinateSystem = PCS
    .CoordinateSystem.Export (Str1)
    Label1.Caption = DisplayCoords(Layer1)
  End With
  MsgBox "坐标系文件已经产生"
End Sub

Private Function DisplayCoords(myLayer As MapObjects2.MapLayer) As String
  Dim coordSys
  Dim PCS As New MapObjects2.ProjCoordSys
  Dim GCS As New MapObjects2.GeoCoordSys
  
  Set coordSys = myLayer.CoordinateSystem
  If coordSys.IsProjected Then
    Set PCS = myLayer.CoordinateSystem
    DisplayCoords = "图层为投影坐标系，Type＝" & PCS.Type & "，Unit＝" & PCS.Unit.name & _
    "，Projection＝" & PCS.Projection.name & "，GeoCoordSys＝" & PCS.GeoCoordSys.Type
  ElseIf Not coordSys.IsProjected Then
    Set GCS = myLayer.CoordinateSystem
    DisplayCoords = "图层为地理坐标系，Type＝" & GCS.Type & "，Unit＝" & GCS.Unit.name & _
    "，Datum＝" & GCS.Datum.name & "，PrimeMeridian＝" & GCS.PrimeMeridian.name
  End If
End Function

Private Sub Form_Load()
  DrawLayer
  Me.Caption = "坐标系文件产生"
  Command1.Caption = "开始"
End Sub

Private Sub DrawLayer()
  Dim Layer As MapLayer
     
  On Error GoTo Err1
  dc.Database = App.Path + "\..\" + "Mexico"
  Set Layer = New MapLayer
  Set Layer.GeoDataset = dc.FindGeoDataset("states")
  Label1.Caption = DisplayCoords(Layer)
  Map1.Layers.Add Layer
  
  Set Layer = New MapLayer
  Set Layer.GeoDataset = dc.FindGeoDataset("states1")
  Map1.Layers.Add Layer
  Exit Sub
  
Err1:
  If dc.ConnectError = 0 Then
    MsgBox "没找到图层", vbInformation, "MO示例"
  Else
    MsgBox ConnectErrorMsg(dc.ConnectError), vbInformation, "MO示例"
  End If
  End
End Sub