曲目跳转.frm

Windows API函数,希望大伙有用哦

VERSION 5.00
Begin VB.Form Form4 
   Caption         =   "Form4"
   ClientHeight    =   1140
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   5175
   LinkTopic       =   "Form3"
   ScaleHeight     =   1140
   ScaleWidth      =   5175
   StartUpPosition =   3  '窗口缺省
   Begin VB.TextBox Text1 
      Alignment       =   1  'Right Justify
      Height          =   305
      Left            =   2280
      Locked          =   -1  'True
      TabIndex        =   4
      Text            =   "Text1"
      Top             =   150
      Width           =   1365
   End
   Begin VB.CommandButton Command4 
      Caption         =   "停止播放"
      Height          =   315
      Left            =   3720
      TabIndex        =   3
      Top             =   690
      Width           =   1185
   End
   Begin VB.CommandButton Command3 
      Caption         =   "下一曲目>>"
      Height          =   315
      Left            =   2520
      TabIndex        =   2
      Top             =   690
      Width           =   1185
   End
   Begin VB.CommandButton Command2 
      Caption         =   "<<上一曲目"
      Height          =   315
      Left            =   1320
      TabIndex        =   1
      Top             =   690
      Width           =   1185
   End
   Begin VB.CommandButton Command1 
      Caption         =   "播    放"
      Height          =   315
      Left            =   120
      TabIndex        =   0
      Top             =   690
      Width           =   1185
   End
   Begin VB.Label Label1 
      AutoSize        =   -1  'True
      Caption         =   "当前曲目："
      Height          =   180
      Left            =   1290
      TabIndex        =   5
      Top             =   210
      Width           =   900
   End
End
Attribute VB_Name = "Form4"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit
Private Declare Function mciSendString Lib "winmm.dll" Alias "mciSendStringA" (ByVal lpstrCommand As String, ByVal lpstrReturnString As String, ByVal uReturnLength As Long, ByVal hwndCallback As Long) As Long
    Dim S As String, Tracks As Integer, CurTrack As Integer
Private Sub Form_Load()
' 打开 CD 设备
    mciSendString "Open cdaudio alias CDRom", vbNullString, 0, 0
    S = String(256, Chr(0))
    mciSendString "Status CDRom number of tracks", S, Len(S), 0
    Tracks = Val(S)
' 将播放曲目定位在第一首乐曲
    CurTrack = 1
    mciSendString "Status CDRom position track " & CurTrack, S, Len(S), 0
    Text1 = CurTrack
End Sub
Private Sub Command1_Click()
' 播放音乐
    mciSendString "Play CDRom", vbNullString, 0, 0
End Sub
Private Sub Command2_Click()
' 播放上一曲目
    If CurTrack > 1 Then
        CurTrack = CurTrack - 1
      Else
        CurTrack = Tracks
    End If
  Text1 = CurTrack
  mciSendString "Status CDRom position track " & CurTrack, S, Len(S), 0
  mciSendString "Play CDRom from " & Left(S, 8), vbNullString, 0, 0
End Sub
Private Sub Command3_Click()
' 播放下一曲目
    If CurTrack < Tracks Then
        CurTrack = CurTrack + 1
    Else
        CurTrack = 1
    End If
  Text1 = CurTrack
  mciSendString "Status CDRom position track " & CurTrack, S, Len(S), 0
  mciSendString "Play CDRom from " & Left(S, 8), vbNullString, 0, 0
End Sub
Private Sub Command4_Click()
' 停止播放
    mciSendString "Stop CDRom", vbNullString, 0, 0
End Sub