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“如何播放Avi、Wave、midi文件”、：
“谁知道用api播放avi,mpg的详细方法？要可以设定将图像放置到设定的窗体中”、
“如何同时播放两个Wav文件”
的问题，其实用一个类模块就一切搞定，不需要什么控件之类的东西，下面这个类模块(不知从哪里找来的)，我研究后将它修改得更好用了，将下面这个类模块存为Mmedia.cls
注释：----------------------------------------------------
Option EXPlicit
注释：--------------TrueZq 最新更新2001-01-12---------------------
注释：文件名： MMedia.cls
注释：说明： : 一个多媒体类,能播放Avi、Wave、Midi文件
注释：用法：
注释：Dim Multimedia As New Mmedia
注释：Multimedia.mmOpen "c: est.wav"
注释：Multimedia.mmPlay
注释：！记住：在程序结束时，一定要用Set Multimedia=nothing释放资源！！！
注释：-----------------------------------------------------
注释： -=-=-=- 属性 -=-=-=-
注释： sFilename 当前的文件名
注释： nLength 文件长度（只读）
注释： nPosition 当前位置
注释： sStatus 当前状态（只读）
注释： bWait True/False.决定是否等待播放完
注释： -=-=-=- 方法 -=-=-=-=-
注释： mmOpen <Filename> 打开要播放的文件
注释： mmClose 关闭当前文件
注释： mmPause 暂停
注释： mmStop 停止 停止后可以跳到开始再次播放
注释： mmSeek <Position> Seeks to a position in the file
注释： mmPlay 播放
注释：--------------------------------------------------------------
Private sAlias As String 注释：别名
注释：Private hWnd As Long
Private sFilename As String 注释： 当前的文件名
Private nLength As Single 注释： 文件长度
Private nPosition As Single 注释： 当前位置
Private sStatus As String 注释： 当前状态
Private bWait As Boolean 注释： 决定是否等待播放完
Const WS_CHILD = &H40000000
注释：------------ API 声明 -------------
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
注释：Private Declare Function GetActiveWindow Lib "USER32" () As Integer
注释：当sTheFile是一个Avi文件时，参数hWnd指定动画在哪里播放
注释：若hWnd=0，则新开一个窗口播放动画。
注释：如果听不到Midi音乐，请在Windows下用媒体播放器测试一下。
注释：文件名不能带空格
Public Sub mmOpen(ByVal sTheFile As String, Optional hWnd As Long = 0)
Dim nReturn As Long
Dim sType As String 注释：文件类型
Static nNum As Integer
If sAlias <> "" Then 注释：关闭开始打开的文件
mmClose
End If
If (Dir(sTheFile) = "") Then 注释：判断是否是一个存在的文件
sFilename = "文件" & sTheFile & " 不存在！"
Exit Sub
Else
sFilename = sTheFile
注释： nNum = nNum + 1
End If
注释： Stop
sAlias = sFilename 注释：用文件名作别名，避免别名冲突！
注释： 判断文件类型
Select Case UCase$(Right$(sTheFile, 3))
Case "WAV"
sType = "Waveaudio"
Case "AVI"
sType = "AviVideo"
Case "MID"
sType = "Sequencer"
Case Else
注释： 未知文件格式，退出。
Exit Sub
End Select
If sType = "AviVideo" And hWnd > 0 Then
nReturn = mciSendString("open " & sTheFile & " ALIAS " & sAlias _
& " TYPE AVIVideo parent " & hWnd & " style " & LTrim$(Str$(WS_CHILD)), 0&, 0, 0)
Else
nReturn = mciSendString("Open " & sTheFile & " ALIAS " & sAlias _
& " TYPE " & sType, "", 0, 0)
End If
End Sub
注释：关闭当前打开的多媒体文件
Public Sub mmClose()
Dim nReturn As Long
注释：如果没有文件打开，则退出
If sAlias = "" Then Exit Sub
nReturn = mciSendString("Close " & sAlias, "", 0, 0)
sAlias = ""
sFilename = ""
End Sub
注释：暂停
Public Sub mmPause()
Dim nReturn As Long
If sAlias = "" Then
Exit Sub
ElseIf Status = "paused" Then 注释：如果先前已经暂停了，则解除暂停
mmPlay
Else
nReturn = mciSendString("Pause " & sAlias, "", 0, 0)
End If
注释：nPosition = Position
End Sub
注释：播放
Public Sub mmPlay()
Dim nReturn As Long
If sAlias = "" Then
Exit Sub
ElseIf Position = Length Then 注释：如果已经到末尾
mmSeek 0 注释：跳到开始处
End If
If bWait Then
nReturn = mciSendString("Play " & sAlias & " wait", "", 0, 0)
Else
nReturn = mciSendString("Play " & sAlias, "", 0, 0)
End If
End Sub
注释：停止
注释：停止后跳到开始,以便再次播放
Public Sub mmStop()
Dim nReturn As Long
If sAlias = "" Then Exit Sub
nReturn = mciSendString("Stop " & sAlias, "", 0, 0)
mmSeek 0 注释：跳到开始位置
End Sub
注释：跳到指定的位置,并且处于暂停状态
注释：当nPosition的值>Length 或者nPosition<0时，将忽略这次操作
Public Sub mmSeek(ByVal nPosition As Single)
Dim nReturn As Long
nReturn = mciSendString("Seek " & sAlias & " to " & nPosition, "", 0, 0)
End Sub
注释：方法Filename返回当前打开的文件名
Property Get filename() As String
filename = sFilename
End Property
注释：指定要播放的文件名，然后将它打开
注释：对于需要指定容器的Avi文件，不要以这种方式打开。
Property Let filename(ByVal sTheFile As String)
mmOpen sTheFile
End Property
注释：读取属性Wait的值
注释：Msgbox Multimedia.Wait
Property Get Wait() As Boolean
Wait = bWait
End Property
注释：设置等待属性
注释：用法：Multimedia.Wait=True
Property Let Wait(bWaitValue As Boolean)
bWait = bWaitValue
End Property
注释：获得长度值
Property Get Length() As Single
Dim nReturn As Long, nLength As Integer
Dim sLength As String * 255
If sAlias = "" Then
Length = 0
Exit Property
End If
nReturn = mciSendString("Status " & sAlias & " length", sLength, 255, 0)
nLength = InStr(sLength, Chr$(0))
Length = Val(Left$(sLength, nLength - 1))
End Property
Property Let Position(ByVal nPosition As Single)
mmSeek nPosition
End Property
注释：获取当前位置
Property Get Position() As Single
Dim nReturn As Integer, nLength As Integer
Dim sPosition As String * 255
If sAlias = "" Then Exit Property
nReturn = mciSendString("Status " & sAlias & " position", sPosition, 255, 0)
nLength = InStr(sPosition, Chr$(0))
Position = Val(Left$(sPosition, nLength - 1))
End Property
注释：当前打开文件的状态
注释：有以下几种：playing paused stopped
Property Get Status() As String
Dim nReturn As Integer, nLength As Integer
Dim sStatus As String * 255
If sAlias = "" Then Exit Property
nReturn = mciSendString("Status " & sAlias & " mode", sStatus, 255, 0)
nLength = InStr(sStatus, Chr$(0))
Status = Left$(sStatus, nLength - 1)
End Property
注释：从头开始播放
Public Sub mmRestart()
Dim nReturn As Long
If sAlias = "" Then Exit Sub
mmSeek 0
mmPlay
End Sub
注释：类的初始化
Private Sub Class_Initialize()
注释： sAlias = "" 注释：别名初值为空
End Sub
注释：关闭打开的多媒体设备
注释：当该类的对象所在的窗体（或模块）卸载时，自动调用该过程
Private Sub Class_Terminate()
mmClose
End Sub
注释：----------------------------------------------------
[用法]
1、
比如要在窗体上播放一个动画,只需3个语句就搞定。
Dim MmAvi As New Mmedia
MmAvi.mmOpen "G: esourceAviTest.avi", Me.hWnd
MmAvi.mmPlay
2、循环播放
Private Sub Timer1_Timer()
Dim S As String
S = "当前文件：" & MmAvi.filename & vbCrLf & "当前位置：" & MmAvi.Position _
& "总长度：" & MmAvi.Length & "当前状态：" & MmAvi.Status
Label1.Caption = S
If MmAvi.Status = "stopped" Then MmAvi.mmRestart
End sub
3、同时播放几个文件（类型可以相同、可以不同）
在Form1中加入Private MmWave(1) As New Mmedia
在需要播放的地方加上：
MmWave(0).mmOpen "G: esourcewavem16.wav"
MmWave(1).mmOpen "G: esourcewaveWelcom98.wav"
MmWave(0).mmPlay
MmWave(1).mmPlay
4、将动画放入一个圆形区域播放
Dim hr As Long
Dim usew&, useh&
Dim MmAvi As New Mmedia
usew& = Frame1.Width / Screen.TwipsPerPixelX
useh& = Frame1.Height / Screen.TwipsPerPixelY
usew = useh
hr& = CreateEllipticRgn(0, 0, usew, useh)
Call SetWindowRgn(Frame1.hWnd, hr, True)
MmAvi.mmOpen "G: esourceAVistart.avi", Frame1.hWnd
MmAvi.mmPlay
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