用多媒体学vb.net 用多媒体学sql server( 四 )


Select Case UCase$(Right$(sTheFile, 3))
Case "WAV"
sType = "Waveaudio"
Case "AVI"
sType = "AviVideo"
Case "MID"
sType = "Sequencer"
Case Else
' If the file extension is not known then exit the subroutine
Exit Sub
End Select
sAlias = Right$(sTheFile, 3)Minute(Now)
' At this point there is no file open, and we have determined the
' file type. Now would be a good time to open the new file.
' Note: if the name contains a space we have to enclose it in quotes
If InStr(sTheFile, " ") Then sTheFile = Chr(34)sTheFileChr(34)
nReturn = mciSendString("Open "sTheFile" ALIAS "sAlias _
" TYPE "sType" wait", "", 0, 0)
End Sub
Public Sub mmClose()
' Closes the currently opened multimedia file
' Declare a variable to hold the return value from the mciSendString
' command
Dim nReturn As Long
' If there is no file currently open then exit the subroutine
If sAlias = "" Then Exit Sub
nReturn = mciSendString("Close "sAlias, "", 0, 0)
sAlias = ""
sFilename = ""
End Sub
Public Sub mmPause()
' Pause playback of the file
' Declare a variable to hold the return value from the mciSendString
' command
Dim nReturn As Long
' If there is no file currently open then exit the subroutine
If sAlias = "" Then Exit Sub
nReturn = mciSendString("Pause "sAlias, "", 0, 0)
End Sub
Public Sub mmPlay()
' Plays the currently open file, from the current position
' Declare a variable to hold the return value from the mciSendString
' command
Dim nReturn As Long
' If there is no file currently open, then exit the routine
If sAlias = "" Then Exit Sub
' Now play the file
If bWait Then
nReturn = mciSendString("Play "sAlias" wait", "", 0, 0)
Else
nReturn = mciSendString("Play "sAlias, "", 0, 0)
End If
End Sub
Public Sub mmStop()
' Stop using a file totally, be it playing or whatever
' Declare a variable to hold the return value from mciSendString
Dim nReturn As Long
' If there is no file currently open then exit the subroutine
If sAlias = "" Then Exit Sub
nReturn = mciSendString("Stop "sAlias, "", 0, 0)
End Sub
Public Sub mmSeek(ByVal nPosition As Single)
' Seeks to a specific position within the file
' Declare a variable to hold the return value from the mciSendString
' function
Dim nReturn As Long
nReturn = mciSendString("Seek "sAlias" to "nPosition, "", 0, 0)
End Sub
Property Get Filename() As String
' Routine to return a value when the programmer asks the
' object for the value of its Filename property
Filename = sFilename
End Property
Property Let Filename(ByVal sTheFile As String)
' Routine to set the value of the filename property, should the programmer
' wish to do so. This implies that the programmer actually wants to open
' a file as well so control is passed to the mmOpen routine
mmOpen sTheFile
End Property
Property Get Wait() As Boolean
' Routine to return the value of the object's wait property.
Wait = bWait
End Property
Property Let Wait(bWaitValue As Boolean)
' Routine to set the value of the object's wait property
bWait = bWaitValue
End Property
Property Get Length() As Single
' Routine to return the length of the currently opened multimedia file
' Declare a variable to hold the return value from the mciSendString
Dim nReturn As Long, nLength As Integer
' Declare a string to hold the returned length from the mci Status call
Dim sLength As String * 255
' If there is no file open then return 0
If sAlias = "" Then
Length = 0
Exit Property
End If
nReturn = mciSendString("Status "sAlias" length", sLength, 255, 0)

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