传递C＃数据类型参数，DLL用C ++编写？ [英] Passing C# data type parameters to dll written in C++?

问题描述

上还是从这里开始的一个问题工作
的调用C ++ DLL函数从C＃：。结构，字符串和wchar_t的阵列，但用不同的方法

Still working on a problem that started from here Calling C++ dll function from C#: Of structs, strings and wchar_t arrays., but with a different approach.

继这个例子中调用从非托管代码托管代码，反之亦然我写了一个托管包装在C ++访问取消管理类的非托管C ++的dll

Following the example Calling Managed Code from Unmanaged Code and vice-versa I wrote a managed wrapper in C++ to access the unmanages class in the unmanaged C++ dll.

它看起来是这样的：

//in header file
public __gc class TSSLDllWrapper
{
public:
TSSLDllWrapper();
     //this is the unmanaged class
CcnOCRsdk * _sdk;

bool convertHKID_Name(char *code, RECO_DATA *o_data);
};

//in .cpp file
TSSLDllWrapper::TSSLDllWrapper(void)
{
  _sdk = new CcnOCRsdk();
}

bool TSSLDllWrapper::convertHKID_Name(char *code, RECO_DATA *o_data)
{
return _sdk->convertHKID_Name(code, o_data);
}

//C++ RECO_DATA structure definition:
struct RECO_DATA{
wchar_t FirstName[200];
wchar_t Surname[200];
};

现在我有一个dll，我可以导入到我的C＃项目。

Now I have a dll that I can import into my C# project.

下面然而问题：
当我想从dll文件调用方法，就像这样：

Here is the problem however: When I want to call the method from the dll file, like this:

TSSLDllWrapper wrapper = new TSSLDllWrapper();
bool res = wrapper.convertHKID_NameSimple( //need to pass parameters here );

据预计，C ++参数 - 指向char和RECO_DATA

It expects the C++ parameters - pointers to char and RECO_DATA.

我怎样才能解决这个问题，并从C＃代码通过C ++类型？

How can I fix this and pass C++ types from C# code?

推荐答案

对于大多数C转换的一种方法数据类型是使用的PInvoke互操作Assitant 。它将创建适当的C＃/ VB.Net类型最C结构。这里是输出RECO_DATA

One way to convert most C data types is to use the PInvoke Interop Assitant. It will create proper C# / VB.Net types for most C structures. Here is the output for RECO_DATA

[System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential, CharSet=System.Runtime.InteropServices.CharSet.Unicode)]
public struct RECO_DATA {

    /// wchar_t[200]
    [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValTStr, SizeConst=200)]
    public string FirstName;

    /// wchar_t[200]
    [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.ByValTStr, SizeConst=200)]
    public string Surname;
}

有关的字符*参数，你可以传递IntPtr.Zero或使用元帅。 StringToCoTaskMemAnsi来完成这项工作。

For the char* parameter, you can pass IntPtr.Zero or use Marshal.StringToCoTaskMemAnsi to get the job done.

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