如何在 VB.NET 中挂载软盘 - VBA

简介

在 VB.NET 中，挂载软盘的方法比较简单，可以通过调用 Win32 API 来实现。以下是具体的代码实现过程。

代码实现

导入 Win32 API

首先需要导入 Win32 API，用于实现对虚拟软盘的访问和操作。

Imports System.Runtime.InteropServices

Public Class Form1
    Private Declare Function _lopen Lib "kernel32.dll" (ByVal lpPathName As String, ByVal iReadWrite As Integer) As Integer
    Private Declare Function CloseHandle Lib "kernel32.dll" (ByVal hObject As Integer) As Integer
    Private Declare Function DeviceIoControl Lib "kernel32.dll" (ByVal hDevice As Integer, ByVal dwIoControlCode As Integer, ByVal lpInBuffer As Integer, ByVal nInBufferSize As Integer, ByVal lpOutBuffer As IntPtr, ByVal nOutBufferSize As Integer, ByRef lpBytesReturned As Integer, ByVal lpOverlapped As IntPtr) As Integer
    Private Declare Function CreateFile Lib "kernel32.dll" Alias "CreateFileA" (ByVal lpFileName As String, ByVal dwDesiredAccess As Integer, ByVal dwShareMode As Integer, ByVal lpSecurityAttributes As Integer, ByVal dwCreationDisposition As Integer, ByVal dwFlagsAndAttributes As Integer, ByVal hTemplateFile As Integer) As Integer
    Private Declare Function DefineDosDevice Lib "kernel32.dll" Alias "DefineDosDeviceA" (ByVal dwFlags As Integer, ByVal lpDeviceName As String, ByVal lpTargetPath As String) As Integer

    Const GENERIC_READ = &H80000000
    Const GENERIC_WRITE = &H40000000
    Const OPEN_EXISTING = 3
    Const CREATE_NEW = 1
    Const FILE_ATTRIBUTE_NORMAL = &H80
    Const IOCTL_FDC_GET_VERSION = &H840020
    Const IOCTL_FDC_LOCK_FDC = &H840024
    Const IOCTL_FDC_UNLOCK_FDC = &H840028
    Const IOCTL_FDC_EJECT_MEDIA = &H840032
    Const IOCTL_FDC_INSERT_MEDIA = &H840036
End Class

挂载软盘

然后，可以调用以下代码挂载软盘。注意，这里将软盘映像文件的路径作为参数传入。

Public Sub MountFloppy(ByVal path As String)
    Dim handle As Integer
    Dim lpBytesReturned As Integer
    Dim targetPath As String
    Dim driveLetter As String
    targetPath = path.Replace("\", "\\")
    driveLetter = GetAvailableDriveLetter()
    DefineDosDevice(0, driveLetter & ":", "\\.\Floppy" & CStr(1))
    handle = CreateFile("\\.\A:", GENERIC_READ Or GENERIC_WRITE, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0)
    DeviceIoControl(handle, IOCTL_FDC_LOCK_FDC, 0, 0, IntPtr.Zero, 0, lpBytesReturned, IntPtr.Zero)
    DeviceIoControl(handle, IOCTL_FDC_EJECT_MEDIA, 0, 0, IntPtr.Zero, 0, lpBytesReturned, IntPtr.Zero)
    DeviceIoControl(handle, IOCTL_FDC_INSERT_MEDIA, Marshal.StringToHGlobalAnsi(targetPath).ToInt32, targetPath.Length, IntPtr.Zero, 0, lpBytesReturned, IntPtr.Zero)
    DeviceIoControl(handle, IOCTL_FDC_UNLOCK_FDC, 0, 0, IntPtr.Zero, 0, lpBytesReturned, IntPtr.Zero)
    CloseHandle(handle)
End Sub

获取可用的驱动器号

这里还需要一个函数来获取当前可用的驱动器号。

Public Function GetAvailableDriveLetter() As String
    Dim driveLetter As Char
    For i As Integer = Asc("A") To Asc("Z")
        driveLetter = Chr(i)
        If Not My.Computer.FileSystem.DirectoryExists(driveLetter & ":\") Then
            Return driveLetter
        End If
    Next
    Throw New Exception("No available drive letters.")
End Function

总结

通过调用 Win32 API，可以在 VB.NET 中挂载软盘。这样就可以方便地读取软盘映像文件中的数据了。