知道文件名，怎样调用关联应用程序打开此文件（VB解析）

'首先声明一个API函数，是什么意思自己去查API手册吧！

Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long
'然后写一个函数

'********************************************************
Private Sub OpenFile(ByVal fName As String)
    ShellExecute hwnd, "open", fName, "", "", 1
End Sub
'********************************************************

'在窗体上放两个控件 Command1 ， CommonDialog1

'然后写如下过程

Private Sub Command1_Click()
On Error GoTo SelErr
    CommonDialog1.DialogTitle = "选择要打开的文件"
    CommonDialog1.CancelError = True
    CommonDialog1.ShowOpen
    OpenFile CommonDialog1.FileName
SelErr:
    Dim Errmsg As String
    Errmsg = Error
    If Errmsg = "选定“取消”。" Then
        MsgBox "没有选定的文件"
    Else
        MsgBox Error
    End If
End Sub

'完事儿了，快试试吧！！！