使用COM传递数组？ [英] Passing an array using COM?

问题描述

我是一个用ATL编写的COM对象，可用于C ++应用程序，并且我想在两者之间传递一个BYTE数组。到目前为止，我对COM / IDL的经验仅限于传递简单类型（BSTR，LONG等）。

I am a COM object written in ATL that is used from a C++ application, and I want to pass an array of BYTEs between the two. My experience of COM/IDL so far is limited to passing simple types (BSTRs, LONGs, etc.).

是否有一种比较简单的方法来传递COM对象调用方数组？例如，我想传递原始图像（TIFF），而不是弄乱临时文件。

Is there a relatively easy way to have the COM object pass an array to the caller? For example, I want to pass a raw image (TIFF) instead of messing with temporary files.

推荐答案

尝试传递safearray变体到COM对象。像这样将BYTE数组放到safearray变量中....

Try passing a safearray variant to the COM Object. Something like this to put a BYTE array inside a safearray variant....

bool ArrayToVariant(CArray<BYTE, BYTE>& array, VARIANT& vtResult)
{
SAFEARRAY FAR*  psarray;
SAFEARRAYBOUND sabounds[1]; 

sabounds[0].lLbound=0;
sabounds[0].cElements = (ULONG)array.GetSize();

long nLbound;

psarray = SafeArrayCreate(VT_UI1, 1, sabounds);
if(psarray == NULL)
    return false;

for(nLbound = 0; nLbound < (long)sabounds[0].cElements ; nLbound++){
    if(FAILED(SafeArrayPutElement(psarray, &nLbound, &array[nLbound]))){
        SafeArrayDestroy(psarray);
        return false;
    }
}

VariantFree(vtResult);
vtResult.vt = VT_ARRAY|VT_UI1;
vtResult.parray = psarray;
return true;
}

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