VB API学习（四）——打开和关闭光驱

Eddy 发布于2010-1-21 18:44:13 分类: 程序设计已浏览loading次网友评论1条 我要评论

用到的API函数：CDdoor

声明：

Private Declare Function CDdoor Lib "winmm.dll" Alias "mciSendStringA" _
　　　 ( _
　　　 ByVal lpstrCommand As String, _ 　　　　　　String，这是控制命令参数
　　　 ByVal lpstrReturnString As String, _　　　　String，这是返回值
　　　 ByVal uReturnLength As Long, _　　　　　　　Long，返回值长度参数
　　　 ByVal hwndCallback As Long _
　　　 ) As Long

使用：

Call CDdoor("set CDAudio door closed", 0, 0, 0)　　用以关闭光驱门
Call CDdoor("set CDAudio door open", 0, 0, 0)　　　用以打开光驱门

实例代码：

Option Explicit
'说明：CDdoor函数是安装WINDOWS时所自带的winmm.dll文件中包含的函数
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

'CDOpen用来标示光驱开与关的状态
Dim CDOpen As Boolean

Private Sub Command1_Click()
On Error Resume Next

'如果关闭则打开，并且按钮做相应变化
If CDOpen = False Then
Call CDdoor("set CDAudio door open", 0, 0, 0)
CDOpen = True
Command1.Caption = "点击关闭光驱"
Else
'否则关闭
Call CDdoor("set CDAudio door closed", 0, 0, 0)
CDOpen = False
Command1.Caption = "点击打开光驱"
End If
End Sub

Private Sub Form_Load()
CDOpen = False
Call CDdoor("set CDAudio door closed", 0, 0, 0)
End Sub