用VB6.0打開和關閉光驅

在VB6.0的開發環境中，添加一個按鈕，編寫如下代碼：

Option Explicit
''說明：CDdoor函數是安裝Windows時所自帶的winmm.dll文件中包含的函數
Private Declare Function CDdoor Lib "winmm.dll" Alias "mciSendStringA" _
( ByVal lpstrCommand As String,ByVal lpstrReturnString As String, _
ByVal uReturnLength As Long, ByVal hwndCallback As Long ) As Long

Dim CDOpen As Boolean

Private Sub cmdControl_Click()
On Error Resume Next

''如果關閉則打開，並且按鈕做相應變化 
If CDOpen = False Then
Call CDdoor("打開", 0, 0, 0)
CDOpen = True
cmdControl.Caption = "點擊關閉光驅"
Else
''否則關閉
Call CDdoor("關閉", 0, 0, 0)
CDOpen = False
cmdControl.Caption = "點擊打開光驅"
End If
End Sub

Private Sub Form_Load()
CDOpen = False
Call CDdoor("關閉光驅", 0, 0, 0)
End Sub

//注：F5運行，就可以控制光驅了。本示例在Win2003,VB6.0環境下運行提通過。