将带有数组的VB6类型转换为VB.NET结构

Question

我尝试将这些VB6类型转换为VB.NET世界.

Type TRACK_DATA
   Dim reserved As Byte
   Dim Control As Byte
   Dim Tracknumber As Byte
   Dim reserved1 As Byte
   Dim address As Long
End Type

Type CDTOC
  Dim Length As Long
  Dim FirstTrack As Byte
  Dim LastTrack As Byte
  Dim Tracks(100) As TRACK_DATA
End Type

目前的尝试失败了

<System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, Size:=8)>
Structure TRACK_DATA
    Public reserved As Byte
    Public Control As Byte
    Public Tracknumber As Byte
    Public reserved1 As Byte
    Public address As UInteger
End Structure

<System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, Size:=806)>
Structure CDROM_TOC '4 + 1 + 1 + 800 = 806
    Public Length As UInteger
    Public FirstTrack As Byte
    Public LastTrack As Byte
    Public Tracks() As TRACK_DATA 
End Structure
...
Dim MyCD As CDTOC
ReDim MyCD.Tracks(100)

任何提示如何做到这一点？

它是传递参数并将它们返回到外部dll,所以我使用编组但Marshal.SizeOf(MyCD)返回错误的值(12)如果我不使用InterOp Size,并且,welp,所有使用StructureToPtr的尝试结束都是错误的.

以下代码,如果有任何用途可以理解:

    Toc_len = Marshal.SizeOf(MyCD)
    Dim Toc_ptr As IntPtr = Marshal.AllocHGlobal(CInt(Toc_len))

    'open the drive
    ...

    'access to the TOC
    DeviceIoControl(hFile, IOCTL_CDROM_READ_TOC, IntPtr.Zero, 0, Toc_ptr, Toc_len, BytesRead, IntPtr.Zero)

    'copy back the datas from unmanaged memory
    'fails here !
    MyCD = Marshal.PtrToStructure(Toc_ptr, CDTOC.GetType())

Answer 1

这里的链接看起来有一些相当广泛的讨论(包括示例代码):https: //social.msdn.microsoft.com/Forums/en-US/3df9e61d-440f-4bea-9556-b2531b30e5e6/problem-with- DeviceIoControl的功能？论坛= vblanguage

您的结构只是缺少Tracks成员上的属性,告诉编译器它是一个内联100个成员的数组.

从链接:

<StructLayout(LayoutKind.Sequential)> _
Structure CDROM_TOC
    Public Length As UShort
    Public FirstTrack As Byte
    Public LastTrack As Byte
    <MarshalAs(UnmanagedType.ByValArray, SizeConst:=100)> _
    Public TrackData() As TRACK_DATA
End Structure

(链接还包括结构中的一些便利功能,我在这里省略了.)