vb.net读取u盘文件 vb读写文件

关于 VB.NET 2008中U盘的插拔

一下代码将自动完成检测vb.net读取u盘文件：

Imports System.IO

Public Class Form1

Public Const WM_DEVICECHANGE = H219

Public Const DBT_DEVICEARRIVAL = H8000

Public Const DBT_DEVICEREMOVECOMPLETE = H8004

Dim DriveLetter As String

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

If m.Msg = WM_DEVICECHANGE Then

Select Case m.WParam

Case DBT_DEVICEARRIVAL

Dim s() As DriveInfo = DriveInfo.GetDrives

For Each drive As DriveInfo In s

If drive.DriveType = DriveType.Removable Then

DriveLetter = drive.Name.ToString()

Debug.WriteLine("U盘 :" DriveLetter "已插入.")

End If

Next

Case DBT_DEVICEREMOVECOMPLETE

Dim s() As DriveInfo = DriveInfo.GetDrives

For Each drive As DriveInfo In s

If drive.ToString = DriveLetter Then Exit Sub

Next

Debug.WriteLine("U盘:" DriveLetter "已卸载vb.net读取u盘文件！")

End Select

End If

MyBase.WndProc(m)

End Sub

End Class

相关问答

Q1: vb.net读取文件流

dim filename as string = "文件名" Using myfilestream As New FileStream(FileName, FileMode.Open, FileAccess.Read)

Dim data() As Byte

ReDim data(myfilestream.Length - 1)

myfilestream.Read(data, 0, myfilestream.Length)

myfilestream.Close()

' data是你要的结果，为byte()， End Using

Q2: vb.net编程接受U盘准备卸载用的windows消息 DBT_DEVICEQUERYREMOVE总是没反应，据说是因为默认注册的消息里

在我的XP+VB2010环境下，测试U盘插入拔出，没有问题：

Private WM_DEVICECHANGE As Integer = H219

Public Enum WM_DEVICECHANGE_WPPARAMS As Integer

DBT_CONFIGCHANGECANCELED = H19

DBT_CONFIGCHANGED = H18

DBT_CUSTOMEVENT = H8006

DBT_DEVICEARRIVAL = H8000

DBT_DEVICEQUERYREMOVE = H8001

DBT_DEVICEQUERYREMOVEFAILED = H8002

DBT_DEVICEREMOVECOMPLETE = H8004

DBT_DEVICEREMOVEPENDING = H8003

DBT_DEVICETYPESPECIFIC = H8005

DBT_DEVNODES_CHANGED = H7

DBT_QUERYCHANGECONFIG = H17

DBT_USERDEFINED = HFFFF

End Enum

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

If m.Msg = WM_DEVICECHANGE Then

Select Case m.WParam

Case WM_DEVICECHANGE_WPPARAMS.DBT_DEVICEARRIVAL

MsgBox("USB device is just plugged in!")

Case WM_DEVICECHANGE_WPPARAMS.DBT_DEVICEREMOVECOMPLETE

MsgBox("USB device is just taken out")

End Select

End If

MyBase.WndProc(m)

End Sub

Q3: VB中怎样将文件复制到检测到的U盘中去

FileCopy "d:\123\新建文件夹\hlyy.xls", "fbhy.txt"

改为

FileCopy "d:\123\新建文件夹\hlyy.xls", fb "hy.txt"

Q4: vb.net 读取扫描枪USB接口数据的实例

USB比较难抓数据vb.net读取u盘文件，建议是USB模拟串口，或者直接就是串口，这样数据比较好抓。

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vb.net读取u盘文件！

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