vb.net 读取扫描枪USB接口数据的实例

USB比较难抓数据，建议是USB模拟串口，或者直接就是串口，这样数据比较好抓。

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USB上传模式是鼠标光标在哪数据就上传在哪，所以你抓USB的数据的很难！

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VB.NET怎样把USB摄像头在显示器上输出的实时画面（像素信息），引入到数据库.

用directshow获取帧缓存,转换为标准图像格式(比如jpg,png这些),存储到数据库的image字段里就行了.

VB.NET检测插入U盘时执行某段代码，并能获取U盘盘符

以下内容为网络提供,但我自己验证可行,供你参考.

Imports System.IO

Public Class Form1

Public Const WM_DEVICECHANGE = H219

Public Const DBT_DEVICEARRIVAL = H8000

Public Const DBT_CONFIGCHANGECANCELED = H19

Public Const DBT_CONFIGCHANGED = H18

Public Const DBT_CUSTOMEVENT = H8006

Public Const DBT_DEVICEQUERYREMOVE = H8001

Public Const DBT_DEVICEQUERYREMOVEFAILED = H8002

Public Const DBT_DEVICEREMOVECOMPLETE = H8004

Public Const DBT_DEVICEREMOVEPENDING = H8003

Public Const DBT_DEVICETYPESPECIFIC = H8005

Public Const DBT_DEVNODES_CHANGED = H7

Public Const DBT_QUERYCHANGECONFIG = H17

Public Const DBT_USERDEFINED = HFFFF

Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)

If m.Msg = WM_DEVICECHANGE Then

Select Case m.WParam

Case WM_DEVICECHANGE

Case DBT_DEVICEARRIVAL 'U盘插入

ComboBox1.Items.Clear()

Dim s() As DriveInfo = DriveInfo.GetDrives

For Each drive As DriveInfo In s

If drive.DriveType = DriveType.Removable Then

ListBox1.Items.Add("U盘已插入！盘符为:" + drive.Name.ToString())

ComboBox1.Items.Add(drive.Name)

End If

Next

BtnWrite.Enabled = True

BtnRead.Enabled = True

Case DBT_CONFIGCHANGECANCELED

Case DBT_CONFIGCHANGED

Case DBT_CUSTOMEVENT

Case DBT_DEVICEQUERYREMOVE

Case DBT_DEVICEQUERYREMOVEFAILED

Case DBT_DEVICEREMOVECOMPLETE 'U盘卸载

ListBox1.Items.Add("U盘卸载！")

BtnWrite.Enabled = False

BtnRead.Enabled = False

Case DBT_DEVICEREMOVEPENDING

Case DBT_DEVICETYPESPECIFIC

Case DBT_DEVNODES_CHANGED

Case DBT_QUERYCHANGECONFIG

Case DBT_USERDEFINED

End Select

End If

MyBase.WndProc(m)

End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

ListBox1.Items.Add("请您现在插入U盘至USB接口！")

End Sub

Private Sub BtnWrite_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnWrite.Click

If ComboBox1.Text = "" Then

MsgBox("请选择U盘盘符！", MsgBoxStyle.Exclamation, "Warn")

Else

Dim Writer As StreamWriter = Nothing

Try

Dim fileName As String = ComboBox1.Text + "Test.txt"

Writer = New StreamWriter(fileName)

Writer.WriteLine(InputBox("老四，请输入要保存的字符串", "输入信息", "Input then Test String! hehe!"))

MsgBox("Write to " + fileName + " Success!")

Catch ex As Exception

MsgBox(ex.Message, MsgBoxStyle.Critical, "Write 失败")

Finally

If Writer IsNot Nothing Then Writer.Close()

End Try

End If

End Sub

Private Sub BtnRead_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnRead.Click

If ComboBox1.Text = "" Then

MsgBox("请选择U盘盘符！", MsgBoxStyle.Exclamation, "Warn")

Else

Dim Reader As StreamReader = Nothing

Try

Dim fileName As String = ComboBox1.Text + "Test.txt"

Reader = New StreamReader(fileName)

MsgBox("Read from " + fileName + vbCrLf + Reader.ReadToEnd, MsgBoxStyle.Information, "Info")

Catch ex As Exception

MsgBox(ex.Message, MsgBoxStyle.Critical, "Read 失败")

Finally

If Reader IsNot Nothing Then Reader.Close()

End Try

End If

End Sub

End Class

怎样用VB读来自USB口的数据

VB可用MsComm控件读取来自USB转RS232接口的数据。或者使用Winsock 控件接收来自USB网卡的数据。

MSComm 控件通过串行端口传输和接收数据，为应用程序提供串行通讯功能。

利用 WinSock 控件可以与远程计算机建立连接，并通过用户数据文报协议 (UDP)或者传输控制协议

(TCP)进行数据交换。这两种协议都可以用来创建客户与服务器应用程序。

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