抄了某老师的程序学习，建了窗口，2个命令按钮，运行程序，出现错误，频率参数如何读取、？请教诸
位如何能让这段程序运行出效果。
picWidth = picFrequency.ScaleWidth
该行错误提示“无效限定符”，不知道如何解决。
Option Explicit
Private Const WHDR_DONE = &H1
Private Const GMEM_ZEROINIT = &H40
Private Const DEVICEID = -1
Private Type WAVEHDR
lpData As Long
' 指向波形数据缓存的指针，即波形数据缓存的地址
dwBufferLength As Long
' 缓存的长度，缓存的字节数
dwBytesRecorded As Long ' 记录波形数据缓存中有多少字节的数据
dwUser As Long
' User data.
dwFlags As Long
' Flags supplying information about the buffer. Set equal to
zero.
dwLoops As Long
' Number of times to play the loop. Set equal to zero.
lpNext As Long
' Not used
reserved As Long
' Not used
End Type
Private Type WAVEFORMAT
wFormatTag As Integer
nChannels As Integer
nSamplesPerSec As Long
nAvgBytesPerSec As Long
nBlockAlign As Integer
wBitsPerSample As Integer
cbSize As Integer
End Type
Private Declare Function waveInGetNumDevs Lib "winmm" () As Long
Private Declare Function waveInGetDevCaps Lib "winmm" Alias "waveInGetDevCapsA" (ByVal
uDeviceID As Long, ByVal WaveInCapsPointer As Long, ByVal WaveInCapsStructSize As Long) As
Long
Private Declare Function waveInGetErrorText Lib "winmm.dll" Alias "waveInGetErrorTextA"
(ByVal err As Long, ByVal lpText As String, ByVal uSize As Long) As Long
Private Declare Function waveInOpen Lib "winmm.dll" (lphWaveIn As Long, ByVal uDeviceID As
Long, lpFormat As WAVEFORMAT, ByVal dwCallback As Long, ByVal dwInstance As Long, ByVal
dwFlags As Long) As Long
Private Declare Function waveInPrepareHeader Lib "winmm.dll" (ByVal hWaveIn As Long,
lpWaveInHdr As WAVEHDR, ByVal uSize As Long) As Long
Private Declare Function waveInReset Lib "winmm.dll" (ByVal hWaveIn As Long) As Long
Private Declare Function waveInStart Lib "winmm.dll" (ByVal hWaveIn As Long) As Long
Private Declare Function waveInStop Lib "winmm.dll" (ByVal hWaveIn As Long) As Long
Private Declare Function waveInUnprepareHeader Lib "winmm.dll" (ByVal hWaveIn As Long,
lpWaveInHdr As WAVEHDR, ByVal uSize As Long) As Long
Private Declare Function waveInClose Lib "winmm.dll" (ByVal hWaveIn As Long) As Long
Private Declare Function waveInAddBuffer Lib "winmm.dll" (ByVal hWaveIn As Long, lpWaveInHdr
As WAVEHDR, ByVal uSize As Long) As Long
Private Declare Function waveInAddBuff Lib "winmm.dll" Alias "waveInAddBuffer" (ByVal
InputDeviceHandle As Long, ByVal WaveHdrPointer As Long, ByVal WaveHdrStructSize As Long) As
Long
Private Declare Function GlobalAlloc Lib "kernel32" (ByVal wFlags As Long, ByVal dwBytes As
Long) As Long
Private Declare Function GlobalFree Lib "kernel32" (ByVal hmem As Long) As Long
Private Declare Function GlobalLock Lib "kernel32" (ByVal hmem As Long) As Long
Private Declare Function GlobalUnlock Lib "kernel32" (ByVal hmem As Long) As Long
Private Declare Function timeKillEvent Lib "winmm.dll" (ByVal uID As Long) As Long
Private Declare Function timeSetEvent Lib "winmm.dll" (ByVal uDelay As Long, ByVal
uResolution As Long, ByVal lpFunction As Long, ByVal dwUser As Long, ByVal uFlags As Long)
As Long
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any,
Source As Any, ByVal Length As Long)
Private Declare Sub CopyStringFromStruct Lib "kernel32" Alias "RtlMoveMemory" (ByVal a As
String, P As Any, ByVal cb As Long)
Private Declare Sub CopyStructFromPtr Lib "kernel32" Alias "RtlMoveMemory" (struct As Any,
ByVal ptr As Long, ByVal cb As Long)
Private Declare Sub CopyPtrFromStruct Lib "kernel32" Alias "RtlMoveMemory" (ByVal ptr As
Long, struct As Any, ByVal cb As Long)
Private Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal
lpPrevWndFunc As Long, ByVal hwnd As Long, ByVal msg As Long, ByVal wParam As Long, ByRef
lParam As WAVEHDR) As Long
Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As
Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private m_sErrMsg As String * 256
'// 保存错误消息
Private m_hWaveIn As Long
'// 波形输出设备句柄
Private m_wFormat As WAVEFORMAT
'//
Private m_inHdr As WAVEHDR
'//
Private m_hMem As Long
'// 指向分配的内存块的指针
Private m_lBuffersize As Long
'// 存放波形数据的缓存大小
Private m_InData() As Byte
'// 波形数据
Private m_lngRetVal As Long
Private m_CellSpace As Long
Private m_CellWidth As Long
Private m_BarCounts As Long
Private m_ForeColor As Long
Private m_BackColor As Long
'//
'// 接收来自波形输入设备的数据
'//
Private Sub StartInput()
' 设置波形头格式
m_wFormat.wFormatTag = 1
m_wFormat.nChannels = 1 '2
m_wFormat.wBitsPerSample = 16
m_wFormat.nSamplesPerSec = 44100
m_wFormat.nBlockAlign = m_wFormat.nChannels * m_wFormat.wBitsPerSample / 8
m_wFormat.nAvgBytesPerSec = m_wFormat.nSamplesPerSec * m_wFormat.nBlockAlign
m_wFormat.cbSize = Len(m_wFormat)
' 设置波形数据缓存大小
m_lBuffersize = (m_wFormat.nSamplesPerSec * m_wFormat.nBlockAlign * m_wFormat.nChannels
* 0.1) - _
((m_wFormat.nSamplesPerSec * m_wFormat.nBlockAlign * m_wFormat.nChannels
* 0.1) Mod _
(m_wFormat.nBlockAlign))
' 从堆上分配m_lBuffersize大小的内存,用来保存录入的波形数据
m_hMem = GlobalAlloc(GMEM_ZEROINIT, m_lBuffersize)
' 填充波形数据结构
m_inHdr.lpData = GlobalLock(m_hMem)
m_inHdr.dwBufferLength = m_lBuffersize
m_inHdr.dwFlags = 0
m_inHdr.dwLoops = 0
' 现在打开波形输入设备
m_lngRetVal = waveInOpen(m_hWaveIn, DEVICEID, m_wFormat, 0, 0, 0)
If m_lngRetVal <> 0 Then
waveInGetErrorText m_lngRetVal, m_sErrMsg, Len(m_sErrMsg)
MsgBox m_sErrMsg
Exit Sub
End If
' 生成信息头
m_lngRetVal = waveInPrepareHeader(m_hWaveIn, m_inHdr, Len(m_inHdr))
If (m_lngRetVal <> 0) Then
waveInGetErrorText m_lngRetVal, m_sErrMsg, Len(m_sErrMsg)
MsgBox m_sErrMsg
Exit Sub
End If
' 开始记录波形数据
m_lngRetVal = waveInAddBuffer(m_hWaveIn, m_inHdr, Len(m_inHdr))
m_lngRetVal = waveInStart(m_hWaveIn)
tmrRecord.Enabled = True
End Sub
'//
'// 停止接收来自波形输入设备的波形数据
'//
Private Sub StopInput()
tmrRecord.Enabled = False
m_lngRetVal = waveInReset(m_hWaveIn)
m_lngRetVal = waveInStop(m_hWaveIn)
waveInUnprepareHeader m_hWaveIn, m_inHdr, Len(m_inHdr)
GlobalFree m_hMem
m_lngRetVal = waveInClose(m_hWaveIn)
End Sub
'//
'//
获得波形数据
'//
Private Sub CaptureWaveOutput()
Dim lngPtr As Long
' 波形数据缓存中已经填满波形数据
If m_inHdr.dwFlags And WHDR_DONE Then
m_lngRetVal = waveInAddBuffer(m_hWaveIn, m_inHdr, Len(m_inHdr))
If m_lngRetVal <> 0 Then
' 波形数据记录失败"
Exit Sub
End If
' 获得左右声道的波形采样数据
lngPtr = m_inHdr.lpData
ReDim Preserve m_InData(m_inHdr.dwBytesRecorded)
CopyStructFromPtr m_InData(0), lngPtr, m_inHdr.dwBytesRecorded
' 画左右声道波形
DrawWaveform
End If
End Sub
'//
'// 画左右声道波形
'//
Private Sub DrawWaveform()
On Error Resume Next
Dim lOffset As Long
Dim lUsage As Long
Dim lIndex As Long
Dim lPos As Long
Dim picWidth As Long
Dim picHeight As Long
Dim perHeight As Long
picWidth = picFrequency.ScaleWidth
picHeight = picFrequency.ScaleHeight
perHeight = ((picHeight - (m_CellSpace + 1)) / 3)
lOffset = m_CellSpace
For lIndex = 0 To m_BarCounts
lUsage = (m_InData(lIndex) / 255) * picHeight
For lPos = 0 To perHeight
picFrequency.Line (lOffset, lPos * 3)-(lOffset + m_CellWidth, lPos * 3 + 1), _
IIf(lUsage >= 255 * (1 - lPos / perHeight), m_ForeColor, m_BackColor), BF
Next
lOffset = lOffset + m_CellWidth + m_CellSpace
Next
picFrequency.Refresh
End Sub
Private Sub Form_Load()
m_CellSpace = 2
m_CellWidth = 8
m_BarCounts = 32
m_ForeColor = &HC000&
m_BackColor = &H6000&
Me.AutoRedraw = True
Me.ScaleMode = vbPixels
picFrequency.AutoRedraw = True
picFrequency.ScaleMode = vbPixels
picFrequency.DrawWidth = 1
tmrRecord.Interval = 100
End Sub
Private Sub Command1_Click()
StartInput
End Sub
Private Sub Command2_Click()
StopInput
End Sub
Private Sub Form_Unload(Cancel As Integer)
StopInput
End Sub
Private Sub tmrRecord_Timer()
CaptureWaveOutput
End Sub
