封送结构包含结构指针 [英] Marshaling Structure contained structure pointer

问题描述

我有一个问题是将包含从VB.net到C ++ dll的结构指针的结构传递给它。

当我尝试以下代码时，会引发此异常：

'System.Runtime.InteropServices.COMException



在VB.net方面我做：

Hi,

I have a problem to pass a structure contained a structure pointer from VB.net to a C++ dll.
When i try the following code, this exception is raised :
'System.Runtime.InteropServices.COMException

In VB.net side i do :

Private Declare Function Cpp_NOR Lib "XLSTATLINK.dll" (<MarshalAs(UnmanagedType.Struct)> ByRef iData As ST_DataSet) As Double

    <StructLayout(LayoutKind.Sequential, Pack:=8)>
    Structure ST_DataSet
        'doubles1 data
        Public doubles1Loaded As Boolean
        Public doubles1 As ST_MVectDbl
    End Structure 

    <StructLayout(LayoutKind.Sequential, Pack:=8)>
    Structure ST_MVectDbl
        Public nbcols As Long 
        Public nbcolsreserved As Long 
        Public samenbrows As Boolean 
        Public nbrowsmax As Long 
        Public nbrows() As Long 
        Public vectors() As ST_VectDbl 
        Public cLabels() As String 
    End Structure

    <StructLayout(LayoutKind.Sequential, Pack:=8)>
    Structure ST_VectDbl
        Public count As Long 
        Public label As String 
        Public vect() As Double 
    End Structure

在C ++代码中：

And in C++ code :

struct ST_DataSet
{
	//doubles1 data
	VARIANT_BOOL Doubles1Loaded;
	ST_MVectDbl Doubles1;
}

struct ST_MVectDbl
{
	int nbcols; 
	int nbcolsreserved; 
	VARIANT_BOOL samenbrows; 
	int nbrowsmax; 
	SAFEARRAY *nbrows; 
	ST_VectDbl *Vectors; 
	SAFEARRAY *CLabels; 
};

struct ST_VectDbl
{
	int Count; 
	BSTR Label; 
	SAFEARRAY *Vect;
};

XLSTATLINK_API double __stdcall Cpp_NOR(ST_DataSet *iData)
{

}

任何人都可以帮助我吗？

提前致谢

Anyone please can help me ?
Thanks in advance.

推荐答案

当你不需要成为数据封送专家时，不要自杀。



创建一个新的VB.NET程序集（比如Types）并将所有数据结构放在那里。



添加对这个程序集的引用原生和现有的VB.NET项目。



启用托管例如。本机项目中的C ++ / CLI。



而不是......

Don't kill yourself trying to become an expert at data marshaling when you don't need to be one.

Create a new VB.NET assembly (say "Types") and put all your data structures there.

Add a reference to this assembly in both the native and existing VB.NET projects.

Enable managed eg. C++/CLI in the native project.

Instead of ...

XLSTATLINK_API double __stdcall Cpp_NOR(ST_DataSet *iData)
{
 
}

...你可以写点类似......

... you can write something like ...

ref class CPP 
{
public:
static double NOR(Types::ST_DataSet^ iData)
{
    if (iData->Doubles1Loaded) { ... }

    return 0.0;
};

从VB.NET中你可以使用...来调用上面的函数。

From VB.NET you can call the above function using ...

dim iData as ST_DataSet

CPP.NOR(iData)

我不是VB.NET编码器所以我不能保证VB.NET语法是100％。

I'm not a VB.NET coder so I can't promise the VB.NET syntax is 100%.

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