module1.vb

这是一本用Visual Studio.NET进行多媒体编程的读物

Option Strict Off
Option Explicit On
Module Module1
	Public Declare Function mciExecute Lib "winmm.dll" (ByVal lpstrCommand As String) As Integer
	
	Public Const RIFF_ID As Integer = 1179011410
	Public Const RIFF_WAVE As Integer = 1163280727
	Public Const RIFF_FMT As Integer = 544501094
	'Typical header of a simple RIFF WAVE file
	
	Public WavInformation As WAVInfo
	Public GetIt As Boolean
	
	Public Structure WAVInfo
		Dim Riff_Format As Integer
		Dim chunk_size As Integer
		Dim ChunkID As Integer
		Dim fmt As Integer
		Dim Wave_Format As Short
		Dim Channels As Short
		Dim SamplesPerSecond As Integer
		Dim AverageBytesPerSecond As Integer
		Dim BlockAlign As Short
	End Structure
	
	Public Function GetWaveInfo(ByVal FileName As String, ByRef w As WAVInfo) As Boolean
		
		Dim ff As Short
		ff = FreeFile
		
		On Error GoTo ehandler
		FileOpen(ff, FileName, OpenMode.Binary, OpenAccess.Read)
		
		On Error GoTo ehandler_fo
		FileGet(ff, w)
		FileClose(ff)
		
		On Error GoTo ehandler
		
		If w.Riff_Format = RIFF_ID And w.ChunkID = RIFF_WAVE And w.fmt = RIFF_FMT Then
			
			GetWaveInfo = True
		Else
			GetWaveInfo = False
		End If
		
		Exit Function
		
ehandler_fo: 
		FileClose(ff)
ehandler: 
		GetWaveInfo = False
	End Function
End Module