如何创建和初始化C ++双打SAFEARRAY传递给C＃ [英] How to create and initialize SAFEARRAY of doubles in C++ to pass to C#

问题描述

我的C＃方法必须从C调用++

本来我的C＃方法接受类型的参数双重[]，但是从C调用++时就变成了SAFEARRAY

在C ++中我需要从双打的数组获取数据，并填充一个SAFEARRAY。我还没有发现任何样本代码来做到这一点。

任何帮助表示赞赏。

解决方案

以下是创建C ++中的SAFEARRAY代码

 ＃包括< OAIDL.H> 
 
无效CreateSafeArray（SAFEARRAY ** saData）
 {
双数据[10]; //写进去绑定创建SAFEARRAY 
 SAFEARRAYBOUND一些样本数据; 
 Bound.lLbound = 0; 
 Bound.cElements = 10; 
 
 * saData = SafeArrayCreate（VT_R8，1，&安培;行）; 
 
双HUGEP * pdFreq; 
 HRESULT HR = SafeArrayAccessData（* saData，（无效HUGEP * FAR *）及pdFreq）; 
如果（成功（小时））
 {
 //从数据[]复制采样值到这个SAFEARRAY 
表示（DWORD I = 0; I&小于10;我+ +） 
 {
 * pdFreq ++ =数据[I] 
} 
 SafeArrayUnaccessData（* saData）; 
} 
} 
  

释放指针，当你完成类似下面的代码 -

  SAFEARRAY * saData; 
 CreateSafeArray（安培; saData）; //创建安全数组
 //使用SAFEARRAY 
 ... 
 ... 
 
 //调用SafeArrayDestroy摧毁SAFEARRAY 
 SafeArrayDestroy（saData）; 
 saData = NULL; //设置指针为NULL 
  

如果您使用ATL为C ++中声明则更好地利用CComSafeArray atlsafe.h。这是为SAFEARRAY包装。 链接文本

My C# method needs to be invoked from C++

Originally my C# method takes a parameter of type double[], but when calling from C++ it becomes a SAFEARRAY

In C++ I need to take data from an array of doubles, and populate a SAFEARRAY. I have not found any sample code to do this.

Any help is appreciated

解决方案

Following is the code to create a safearray in C++.

#include<oaidl.h>

void CreateSafeArray(SAFEARRAY** saData)        
{
    double data[10]; // some sample data to write into the created safearray
    SAFEARRAYBOUND  Bound;
    Bound.lLbound   = 0;
    Bound.cElements = 10;

    *saData = SafeArrayCreate(VT_R8, 1, &Bound);

    double HUGEP *pdFreq;
    HRESULT hr = SafeArrayAccessData(*saData, (void HUGEP* FAR*)&pdFreq);
    if (SUCCEEDED(hr))
    {
            // copy sample values from data[] to this safearray
        for (DWORD i = 0; i < 10; i++)
        {
            *pdFreq++ = data[i];
        }
        SafeArrayUnaccessData(*saData);
    }
}

Free the pointer when you are finished like the following code-

  SAFEARRAY* saData;
  CreateSafeArray(&saData); // Create the safe array
  // use the safearray
  ...
  ...

  // Call the SafeArrayDestroy to destroy the safearray 
  SafeArrayDestroy(saData);
  saData = NULL; // set the pointer to NULL

If you use ATL for C++, then better use CComSafeArray declared in "atlsafe.h". This is wrapper for SAFEARRAY. link text

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