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！
X猫-思刊办公专营店
如果是usb扫描枪，是焦点在哪它就输入在哪，不能自动对应到相应的文本框
如果是串口扫描枪可以实现你的功能，在代码里判断相应的串口对应文本框
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.
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
