使用网上比较普遍的vb中使用WindowsAPI实现打开文件对话框代码，

Declare  Function  GetOpenFileName Lib  " comdlg32.dll "  Alias _

         " GetOpenFileNameA "  (pOpenfilename  As  OPENFILENAME)  As   Long

 

Type OPENFILENAME

     lStructSize  As   Long

     hwndOwner  As   Long

     hInstance  As   Long

     lpstrFilter  As   String

     lpstrCustomFilter  As   String

     nMaxCustFilter  As   Long

     nFilterIndex  As   Long

     lpstrFile  As   String

     nMaxFile  As   Long

     lpstrFileTitle  As   String

     nMaxFileTitle  As   Long

     lpstrInitialDir  As   String

     lpstrTitle  As   String

     flags  As   Long

     nFileOffset  As   Integer

     nFileExtension  As   Integer

     lpstrDefExt  As   String

     lCustData  As   Long

     lpfnHook  As   Long

     lpTemplateName  As   String

End  Type 

调用代码

Sub  t()

     Dim  ofn  As  OPENFILENAME

     Dim  rtn  As   String

    ofn.lStructSize  =   Len (ofn)

    ofn.hwndOwner  =  Application.hWnd

     ' ofn.hInstance = Application.hInstance

    ofn.lpstrFilter  =   " XML Files (*.xml) "   &   Chr ( 0 )  &   " *.xml "   &   Chr ( 0 )

    ofn.lpstrFile  =   Space ( 254 )

    ofn.nMaxFile  =   255

    ofn.lpstrFileTitle  =   Space ( 254 )

    ofn.nMaxFileTitle  =   255

    ofn.lpstrInitialDir  =   " C: "

    ofn.lpstrTitle  =   " 打开文件 "

    ofn.flags  =   6148

    rtn  =  GetOpenFileName(ofn)

     If  rtn  >=   1   Then

         MsgBox  ofn.lpstrFile

     Else

         MsgBox   " Cancel Was Pressed "

     End   If

End Sub