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标题:VB源代码
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kk205
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VB源代码
为什么不能获得USB设备句柄 我用VB写的应用程序,用的是68013芯片,驱动程序也已经安装好,并且操作系统已经能识别设备,可是应用程序用creatfile就是打不开设备,得不到设备句柄。代码如下: Private Sub Form_Load() 'Handle HidDevice Dim HidDevice As Long DevicePathName = "\\.\ezusb-0" HidDevice = CreateFile _           (DevicePathName, _           GENERIC_WRITE, _           FILE_SHARE_WRITE, _           0, _           OPEN_EXISTING, _           0, _           0)               'INVALID_HANDLE_VALUE = -1     If (HidDevice = INVALID_HANDLE_VALUE) Then       'OpenDevice = False                   'Form1.Shape6.Height = (MaxTemper - 0) * TemperScale            MsgBox " 未发现与之通信的USB设备!" + _        Chr(13) & Chr(10) + _        Chr(13) & Chr(10) + _        " 请确定其硬件设备是否已连接," + _        Chr(13) & Chr(10) + _        "并确定其驱动程序是否已加载。", _        17, "可恶"                Else     MsgBox " 发现与之通信的USB设备!" + _        Chr(13) & Chr(10) + _        Chr(13) & Chr(10) + _        " 请确定," + _        Chr(13) & Chr(10) + _        "!", _        1, "成功打开设备"             'OpenDevice = True     End If End Sub Public Declare Function CreateFile _    Lib "kernel32" _    Alias "CreateFileA" _     (ByVal lpFileName As String, _     ByVal dwDesiredAccess As Long, _     ByVal dwShareMode As Long, _     ByRef lpSecurityAttributes As Long, _     ByVal dwCreationDisposition As Long, _     ByVal dwFlagsAndAttributes As Long, _     ByVal hTemplateFile As Long) _ As Long '***************************************************************** 'API constants. '***************************************************************** 'IOCTL Code 'Public Const FILE_DEVICE_UNKNOWN = &H22 Public Const Cyusb_IOCTL_INDEX = &H800 Public Const METHOD_BUFFERED = &H0 Public Const FILE_ANY_ACCESS = &H0 'CreateFile Public Const GENERIC_READ = &H80000000 Public Const GENERIC_WRITE = &H40000000 Public Const FILE_SHARE_READ = &H1 Public Const FILE_SHARE_WRITE = &H2 Public Const OPEN_EXISTING = 3 'Public Const INVALID_HANDLE_VALUE = -1 Public Const INVALID_HANDLE_VALUE = -1
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2005-05-08 20:35
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