按鈕"Open MP3 File"是用來打開對話框選擇MP3文件，其他5個按鈕分別為Play(播放)、Pause(暫停)、Stopplay(停止播放)、Back(向后跳躍)、 下面就可以編寫代碼了。首先在窗體的"通用聲明"部分聲明函數 Private Declare Function mciSendString Lib "winmm.dll" Alias "mciSendStringA"(Byval lpstrCommand As String,ByVal lpstrRetumString As String,ByVal uReturnLength As long,ByVal hwndCallback as long) As long
Dim mfn As String
下面就是各個對象的代碼了： Private Sub Form_load() mfn="" play.Enabled=False pause.Enabled=False Stopplay.Enabled=False back.Enabled=False prew.Enabled=False Timer1.Enabled=False Timer1.Interval=500 End Sub
Private Sub open_Click() On Error Goto err With CommonDialog1 .CancelError=True .Filter="音樂文件*.mp3;*.wav;*.mid" .Flags=cdlOFNNoChangeDir And cdlOFNPathMustExist .Action=1 stopplay_Click '停止按鈕同時可以設備初始化 mfn=.FileName '這個程序中文件名一定不能帶空格 Form1.Caption=.FileName play.Enabled=True End With play_Click Exit Sub err: End Sub
Private Sub play_Click() On Error Resume Next Dim t As Long t=mciSendString("open " + mfn,0&,0,0) 'Open后邊的空格一定不能丟 Dim ret As String * 128 t=mciSendString("status " + mfn + " length",ret,128,0) '顯示歌曲總長 ret=Left(ret,8) If ret<>"" Then ProgressBar1.Min=0 ProgressBar1.Max=Val(ret) Label3.Caption=gettime(Val(ret)) End If play.Enabled=False pause.Enabled=True stopplay.Enabled=True back.Enabled=True prew.Enabled=True t=mciSendString("status " + mfn +" mode",ret,128,0) '得到設備的當前狀態，是播放還是暫停等等 ret=Left(ret,8) StatusBar1.Panels(1).text=ret '在狀態欄顯示播放狀態 t=mciSendString("play " + mfn + " form " + Str(ProgressBar1.Value),0&,0,0) '開始播放 Timer1.Enabled=True End Sub
Private Sub pause_Click() t%=mciSendString("pause " + mfn,0&,0,0) '發出暫停的命令 play.Enable=True pause.Enabled=False stopplay.Enabled=True back.Enabled=False prew.Enabled=False End Sub
Private Sub stopplay_Click() t%=mciSendString("stop " + mfn,0&,0,0) t%=mciSendString("close " + mfn,0&,0,0) '停止播放 play.Enabled=True pause.Enabled=False stopplay.Enabled=False back.Enabled=False prew.Enabled=False End Sub
Private Sub back_Click() t%=mciSendString("play " + mfn + " from " + Str(ProgressBar1.Value-(ProgressBar1.Max/10)),0&,0,0) '向后跳一小段再播放 End Sub
Private Sub prew_Click() t%=mciSendString("play " + mfn + " from " + Stri(ProgressBar1.Value+(ProgressBar1.Max/10)),0&,0,0) '向前跳一小段再播放 End Sub
Private Sub Timer1_Timer() Dim t As Long Dim ret As String * 128 t=mciSendString("status " + mfn + " position",ret,0,0) '得到當前播放位置 ret=left(ret,8) ProgressBar1.Value=Val(ret) Label1.Caption=gettime(Val(ret)) '顯示歌曲當前時間 If ProgressBar1.Value=ProgressBar1.Max Then stopplay_Click End If t=mciSendString("status " + mfn + " mode",ret,128,0) ret=Left(ret,8) StatusBar1.Panels(1).Text=ret End Sub
Private Sub Form_Unload(Cacel As Integer) t%=mciSendString("stop " + mfn,0&,0,0) t%=mciSendString("close " + mfn,0&,0,0) End Sub
Private Function Gettime(position As Long) As String '這個函數的功能是把以長整型表示的時間轉換為電子鐘式的"**:**" Dim min,sec min=position/1000 min=min/60 sec=min-Int(min) min=Int(min) sec=60 * sec / 100 sec=Int(sec * 100) gettime=Str(min) + ":" + Str(sec) End Function
