clsdirbrowser.cls

实现了基本地图的查询 漫游 放大 缩小等等功能

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
  Persistable = 0  'NotPersistable
  DataBindingBehavior = 0  'vbNone
  DataSourceBehavior  = 0  'vbNone
  MTSTransactionMode  = 0  'NotAnMTSObject
END
Attribute VB_Name = "clsDirBrowser"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False

'使用 WIN95 的选择目录对话框
'声明:
Private Type BrowseInfo
  hWndOwner As Long
  pIDLRoot As Long
  pszDisplayName As Long
  lpszTitle As Long
  ulFlags As Long
  lpfnCallback As Long
  lParam As Long
  iImage As Long
End Type

Private Const BIF_RETURNONLYFSDIRS = 1
Private Const MAX_PATH = 260

Private Declare Sub CoTaskMemFree Lib "ole32.dll" (ByVal hMem As Long)
Private Declare Function lstrcat Lib "kernel32" Alias "lstrcatA" (ByVal lpString1 As String, ByVal lpString2 As String) As Long
Private Declare Function SHBrowseForFolder Lib "shell32" (lpbi As BrowseInfo) As Long
Private Declare Function SHGetPathFromIDList Lib "shell32" (ByVal pidList As Long, ByVal lpBuffer As String) As Long

'函数:
Public Function BrowseForFolder(hWndOwner As Long, sPrompt As String) As String
Dim iNull As Integer
Dim lpIDList As Long
Dim lResult As Long
Dim sPath As String
Dim udtBI As BrowseInfo
  With udtBI
    .hWndOwner = hWndOwner
    .lpszTitle = lstrcat(sPrompt, "")
    .ulFlags = BIF_RETURNONLYFSDIRS
  End With
  lpIDList = SHBrowseForFolder(udtBI)
  If lpIDList Then
    sPath = String$(MAX_PATH, 0)
    lResult = SHGetPathFromIDList(lpIDList, sPath)
    Call CoTaskMemFree(lpIDList)
    iNull = InStr(sPath, vbNullChar)
    If iNull Then
      sPath = Left$(sPath, iNull - 1)
    End If
  End If
  BrowseForFolder = sPath
End Function