P/Invoke Marshalling 帮助 - 嵌套结构 - VB.NET答案

【问题标题】：P/Invoke Marshalling Help - Nested Structures - VB.NETP/Invoke Marshalling 帮助 - 嵌套结构 - VB.NET
【发布时间】：2009-08-28 04:04:41
【问题描述】：

好吧，我到底做错了什么..

“System.TypeLoadException：无法编组类型为“MY_Struct1”的字段“s2”：此字段的类型定义具有布局信息，但托管/非托管类型组合无效或不可编组。”

'VENDORAPI short FunctionEx(Struct1* pstruct1);
 Declare Auto Function FunctionEx Lib "VENDORDLL.dll" (<MarshalAs(UnmanagedType.Struct)> ByRef pstruct1 As MY_Struct1) As Int16

Enum MY_ANEnum
    a
    b
    c
End Enum

Enum MY_ANEnum2
    x
    y
    z
End Enum

Const foo_size = 5
Const foo1_size = 15
Const foo2_size = 25
Const foo3_size = 35
Const superfoo_size = 10
Const superfoo_len = 20

<StructLayout(LayoutKind.Sequential)> _
Structure MY_Struct1
'typedef struct
'{
'short       Id;
'ANEnum      aEnum;
'Struct2     s2;
'} Struct1;
    <MarshalAs(UnmanagedType.I2)> Public Id As Int16
    <MarshalAs(UnmanagedType.I2)> Public aEnum As MY_ANEnum
    <MarshalAs(UnmanagedType.Struct)> Public s2 As MY_Struct2
End Structure

<StructLayout(LayoutKind.Sequential)> _
Structure MY_Struct2

'struct Struct2
'{
'Struct3   s3;
'Struct4   s4;
'Struct5   s5;
'Struct6   s6;
'};
    Public s3 As MY_Struct3
    Public s4 As MY_Struct4
    Public s5 As MY_Struct5
    Public s6 As MY_Struct6
End Structure

<StructLayout(LayoutKind.Sequential)> _
Structure MY_Struct3
'struct Struct3
'{
' short  Flag;
' long   Id;
' ANEnum2   aEnum2; 
' char   foo[foo_size];
'};
    <MarshalAs(UnmanagedType.I2)> Public Flag As Int16
    <MarshalAs(UnmanagedType.I4)> Public Id As Int32
    <MarshalAs(UnmanagedType.I2)> Public enum2 As MY_ANEnum2
    <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=foo_size)> Public foo As String
End Structure

<StructLayout(LayoutKind.Sequential)> _
Structure MY_Struct4
'struct Struct4
'{
'char       foo1[foo1_size];
'char       foo2[foo2_size];
'};
    <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=foo1_size)> Public foo1 As String
    <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=foo2_size)> Public foo2 As String
End Structure

<StructLayout(LayoutKind.Sequential)> _
Structure MY_Struct5
'typedef struct
'{
'char       szfoo31[foo3_size];
'char       szfoo32[foo3_size];
'char       szfoo33[foo3_size];
'char       szfoo34[foo3_size];
'} Struct5;
    <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=foo3_size)> Public szfoo31 As String
    <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=foo3_size)> Public szfoo32 As String
    <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=foo3_size)> Public szfoo33 As String
    <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=foo3_size)> Public szfoo34 As String
End Structure

<StructLayout(LayoutKind.Sequential)> _
Structure MY_Struct6
'struct Struct6
'{
'short Id;
'char     aaszSuperfoo[superfoo_len][superfoo_size];
'short siId[superfoo_len];
'short siId2[superfoo_len];     
'};
    <MarshalAs(UnmanagedType.I2)> Public Id As Int16
    <MarshalAs(UnmanagedType.ByValArray, ArraySubType:=UnmanagedType.ByValTStr, SizeConst:=superfoo_len)> Public aaszSuperFoo() As String
    <MarshalAs(UnmanagedType.ByValArray, ArraySubType:=UnmanagedType.I2, SizeConst:=superfoo_len)> Public siId() As Int16
    <MarshalAs(UnmanagedType.ByValArray, ArraySubType:=UnmanagedType.I2, SizeConst:=superfoo_len)> Public siId2() As Int16
End Structure

这里我猜测是和MY_Struct6中的多维数组有关。

我尝试了一个简单的构建和 Marshal.SizeOf() 直接做一个 Marshal.StructureToPtr() 作为测试，它给了我一个无法计算大小的错误。

所有你 P/Invoke 忍者，请在这里给我一个答案，而不是“用 C++ 编写代码”。..

提前致谢。

【问题讨论】：

感谢您的回复。事实证明它与 struct 6 中的部分无关。我在其他地方犯了另一个愚蠢的错误。我也在看看你的建议 Jared。

标签： vb.net pinvoke structure

【解决方案1】：

试试下面的定义。

Partial Public Class NativeConstants

    '''superfoo_size -> 10
    Public Const superfoo_size As Integer = 10

    '''superfoo_len -> 20
    Public Const superfoo_len As Integer = 20
End Class

<System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, CharSet:=System.Runtime.InteropServices.CharSet.[Ansi])>  _
Public Structure Struct6

    '''short
    Public Id As Short

    '''char[200]
    <System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValTStr, SizeConst:=200)>  _
    Public aaszSuperfoo As String

    '''short[20]
    <System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValArray, SizeConst:=20, ArraySubType:=System.Runtime.InteropServices.UnmanagedType.I2)>  _
    Public siId() As Short

    '''short[20]
    <System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValArray, SizeConst:=20, ArraySubType:=System.Runtime.InteropServices.UnmanagedType.I2)>  _
    Public siId2() As Short
End Structure

【讨论】：