VB2010开发USB接口时遇枚举设备问题

Public Declare Function HidD_GetHidGuid Lib "hid.dll" (ByRef HidGuid As GUID) As Long

Public Structure GUID
  Dim data1 As Long
  Dim data2 As Integer
  Dim data3 As Integer
  Dim data4() As Byte
  End Structure

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
  Dim HidGuid As GUID
  Dim DeviceInfoSet As Long
  Dim vbNullString As String = Nothing

  Result = HidD_GetHidGuid(HidGuid) 这里HidGuid出现NULL引用异常
  End Sub

估计GUID这个结构体初始化不正确，望有经验的高手指点一二……

看看这本书，也许对你有帮助：
http://download.csdn.net/source/1673828