如何在c ++中返回两个不同的变量？ [英] How to return two different variable in c++?

问题描述

$ p $ d code code $ c

$ $ $ $ $ $ $ $ $ $ $ $ $
{
return x;
}
}

在C＃

  [DllImport（example.dll，CallingConvention = CallingConvention.Cdecl）] 
 public static extern int mainfun（）; 
  

我只知道如何从C ++返回并调用一个变量到C＃。我正在编写一个程序，我需要从C ++ dll
（ like return x，y;）中调用C＃中的两个不同的变量。请求我需要帮助。

EDIT1：

在C ++中

  struct Point 
 {
 int count_err; 
 int语句; 
} obj 
 externC
 {
 __declspec（dllexport）Point mainfun（）
 {
 return obj; 
} 
} 
  

在C＃

  [StructLayout（LayoutKind.Sequential）] 
 public struct Point 
 {
 public int errsize; 
 public int statmnt; 
} 
 [DllImport（example.dll，CallingConvention = CallingConvention.Cdecl）] 
 public static extern Point mainfun（）; 
 
 errsize = mainfun（）; 
 statmnt = mainFun（）; 
  

这里errsize发出错误 - errsize在当前上下文中不存在 .. 该怎么办？

EDIT2：

在C＃中

  total_errors.Text = p.errsize.ToString（）; 
  

给出相同的错误 - 当前的名称p不存在。上下文

解决方案

定义新的数据结构或数组，这样：

C ++：

  struct Point 
 {
 int count_err; 
 int语句; 
} obj; 
 externC
 {
 __declspec（dllexport）Point mainfun（）
 {
 return obj; 
} 
} 
  

C＃：

  [StructLayout（LayoutKind.Sequential）] 
 public struct Point 
 {
 public int errsize; 
 public int statmnt; 
 } 
 [DllImport（example.dll，CallingConvention = CallingConvention.Cdecl）] 
 public static extern Point mainfun（）; 
 
 Point p = mainfun（）; 
 var errsize = p.errsize; 
 var statmnt = p.statmnt; 
  

dll C++

extern "C"  
{
     __declspec(dllexport) int mainfun()
     {
         return x;
     }
}

In C#

[DllImport("example.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern int mainfun();

I only know how to return and call one variable from C++ to C#. I am writing a program where i need to call two different varables in C# from c++ dll (like return x,y;). Please i need help.

EDIT1:

In C++

struct Point
{
    int count_err;
    int statement;
} obj;
extern "C"  
{
     __declspec(dllexport) Point mainfun()
     {
         return obj;
     }
}

In C#

[StructLayout(LayoutKind.Sequential)] 
public struct Point 
{ 
   public int errsize; 
   public int statmnt; 
} 
[DllImport("example.dll", CallingConvention = CallingConvention.Cdecl)]    
public static extern Point mainfun();

errsize = mainfun();
statmnt = mainfun();

Here errsize is giving an error-"the name 'errsize' does not exist in the current context".. What to do?

EDIT2:

In C#

total_errors.Text = p.errsize.ToString();

giving same error-"the name 'p' does not exist in the current." context"

解决方案

Define new struct or array of data. Something like this:

C++:

struct Point
{
    int count_err;
    int statement;
} obj;
extern "C"  
{
     __declspec(dllexport) Point mainfun()
     {
         return obj;
     }
}

C#:

[StructLayout(LayoutKind.Sequential)] 
public struct Point 
{ 
   public int errsize; 
   public int statmnt; 
} 
[DllImport("example.dll", CallingConvention = CallingConvention.Cdecl)]    
public static extern Point mainfun();

Point p = mainfun();
var errsize = p.errsize;
var statmnt = p.statmnt;

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