将vb6类型转换为VB.net或C#Struct

2023年6月2日 166次阅读

我正在将最初用vb6编写的应用程序转换为vb.net.这个应用程序的一个功能是它将一个“Type”对象发送到一个dll.我尝试将类型转换为结构并调用dll但它似乎不起作用.我被困了一个星期,任何帮助都会非常感激

这是类型的vb6代码

'Define WICS Communications Control Block (CCB).
Type WicsCCBType ' Create user-defined type.
    CCBNum As String * 1
    CCBVer As String * 1
    Resp1  As String * 4
    Resp2  As String * 4
    PLUA   As String * 8
    LLUA   As String * 8
    Mode   As String * 8
    ReqMax As String * 5
    ResMax As String * 5
End Type

以下是dll的调用方式

Private Declare Sub WICSRASP Lib "wicsrasp.dll" (MyWicsCCB As WicsCCBType)
WICSRASP MyWicsCCB

这是我尝试使用vb.net,但它无法正常工作

'Define WICS Communications Control Block (CCB).
    <System.Runtime.InteropServices.StructLayoutAttribute( _
            System.Runtime.InteropServices.LayoutKind.Sequential, _
            CharSet:=System.Runtime.InteropServices.CharSet.[Unicode])> _
    Structure WicsCCBType ' Create user-defined type.
        <MarshalAs(UnmanagedType.ByValTStr, sizeconst:=1)> Dim CCBNum As String
        <MarshalAs(UnmanagedType.ByValTStr, sizeconst:=1)> Dim CCBVer As String
        <MarshalAs(UnmanagedType.ByValTStr, sizeconst:=4)> Dim Resp1 As String
        <MarshalAs(UnmanagedType.ByValTStr, sizeconst:=4)> Dim Resp2 As String
        <MarshalAs(UnmanagedType.ByValTStr, sizeconst:=8)> Dim PLUA As String
        <MarshalAs(UnmanagedType.ByValTStr, sizeconst:=8)> Dim LLUA As String
        <MarshalAs(UnmanagedType.ByValTStr, sizeconst:=8)> Dim Mode As String
        <MarshalAs(UnmanagedType.ByValTStr, sizeconst:=5)> Dim ReqMax As String
        <MarshalAs(UnmanagedType.ByValTStr, sizeconst:=5)> Dim ResMax As String
    End Structure

这是我试图称之为的地方

<System.Runtime.InteropServices.DllImportAttribute("C:\windows\system32\wicsrasp.dll")> _
    Public Shared Sub WICSRASP(
                    ByRef CCB As WicsCCBType,
                    ByRef Request As DAWicsRequestType,
                    ByRef Response As DAWicsResponseType)
    End Sub

 Dim CCB As New modWICSDiary.WicsCCBType()
 CCB.CCBNum = "B"
            CCB.CCBVer = "2"
            CCB.LLUA = "        "
            CCB.Mode = "CICSMO2 "
            CCB.ReqMax = "2100 "
            CCB.ResMax = "2100 "
            CCB.Resp1 = "0   "
            CCB.Resp2 = "0   "
            CCB.PLUA = "WICSPLU "

  NativeMethods.WICSRASP(CCB)

对于值,相同的值适用于vb6类型

再次感谢你

最佳答案 我不知道OP是否已经解决了这个问题,但这是我的看法.

VB6中UDT内的固定长度字符串不作为指针编组,而是内联到结构中.此外,VB6在编组之前将Unicode转换为Ansi. VB6使用4字节对齐.

该类型将使用填充在内存中查看此内容,每个连续字段在图中命名为A到I,并且_由于对齐而是填充字节.

CCBNum As String * 1     
|
|+-CCBVer As String * 1     
||
||  Resp1  As String * 4
||  |
||  |   Resp2  As String * 4     
||  |   |
||  |   |   PLUA   As String * 8     
||  |   |   |
||  |   |   |       LLUA   As String * 8     
||  |   |   |       |
||  |   |   |       |       Mode   As String * 8     
||  |   |   |       |       |
||  |   |   |       |       |       ReqMax As String * 5     
||  |   |   |       |       |       |
||  |   |   |       |       |       |       ResMax As String * 5 
||  |   |   |       |       |       |       |
||  |   |   |       |       |       |       |
VV  V   V   V       V       V       V       V

AB__CCCCDDDDEEEEEEEEFFFFFFFFGGGGGGGGHHHHH___IIIII___

因此CharSet应该是Ansi,StructAlignment应该是4.使用ByValTString很好,就像使用SizeConst一样.

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