form05.frm

VB＋M0开发GIS代码

VERSION 5.00
Object = "{9BD6A640-CE75-11D1-AF04-204C4F4F5020}#2.0#0"; "Mo20.ocx"
Begin VB.Form Form05 
   Caption         =   "查找指定范围内的特征"
   ClientHeight    =   6735
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   7710
   LinkTopic       =   "Form1"
   ScaleHeight     =   6735
   ScaleWidth      =   7710
   StartUpPosition =   2  'CenterScreen
   Begin VB.ComboBox Combo1 
      Height          =   300
      Left            =   4560
      TabIndex        =   2
      Text            =   "Combo1"
      Top             =   5760
      Width           =   1335
   End
   Begin MapObjects2.Map Map1 
      Height          =   5415
      Left            =   120
      TabIndex        =   0
      Top             =   120
      Width           =   7455
      _Version        =   131072
      _ExtentX        =   13150
      _ExtentY        =   9551
      _StockProps     =   225
      BackColor       =   16777215
      BorderStyle     =   1
      Contents        =   "Form05.frx":0000
   End
   Begin VB.Label Label1 
      Caption         =   "Label1"
      Height          =   375
      Left            =   960
      TabIndex        =   1
      Top             =   5880
      Width           =   2415
   End
End
Attribute VB_Name = "Form05"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
'Xue Wei,2003/5/17
'SearchByDistance练习；

Option Explicit
Dim rect As New MapObjects2.Rectangle

Private Sub Map1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
  If Button = 1 Then
    Set rect = Map1.TrackRectangle
    Map1.Refresh
  End If
End Sub

Private Sub Map1_AfterLayerDraw(ByVal index As Integer, ByVal canceled As Boolean, ByVal hDC As stdole.OLE_HANDLE)
  Dim Radius As Double
  Dim recset As MapObjects2.Recordset
  Dim sym As New MapObjects2.Symbol
  Dim iLayer As Integer
  
  Select Case Combo1.Text
    Case "州": iLayer = 2
    Case "河流": iLayer = 1
    Case "城市": iLayer = 0
  End Select
  
  If Not rect Is Nothing Then
    Radius = rect.Width * 0.5
    Set recset = Map1.Layers(iLayer).SearchByDistance(rect.Center, Radius, "")
    
    sym.SymbolType = moFillSymbol
    sym.Style = moSolidFill
    sym.color = moLightYellow

    If Not recset.EOF Then
      Map1.DrawShape recset, sym
    End If

    sym.color = moRed
    sym.SymbolType = moFillSymbol
    sym.Style = moLightGrayFill
    Map1.DrawShape rect, sym
  End If
  
  If Not recset.EOF Then
    Label1.Caption = "一共找到" & recset.Count & "个对象。"
  Else
    Label1.Caption = "在地图上画矩形"
  End If
End Sub

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 = moLimeGreen
  Map1.Layers.Add layer
  
  Set layer = New MapLayer
  Set layer.GeoDataset = dc.FindGeoDataset("Rivers")
  layer.Symbol.color = moRed
  Map1.Layers.Add layer
  
  Set layer = New MapLayer
  Set layer.GeoDataset = dc.FindGeoDataset("Cities")
  layer.Symbol.color = moBlue
  Map1.Layers.Add layer
End Sub

Private Sub Form_Load()
  DrawLayer
  Combo1.AddItem "城市"
  Combo1.AddItem "河流"
  Combo1.AddItem "州"
  Combo1.ListIndex = 0
  'Label1.Caption = "在地图上画矩形"
End Sub