将字符串数组从COM传递到C#

时间:2011-11-10 19:41:20

标签: c# c++ visual-c++ com-interop safearray

我需要通过类似COM的接口访问COM dll中的C#方法。其中一个方法需要将一个字符串数组作为输入传递。

创建SAFEARRAY并将其传递给COM Interop。但是,这似乎没有用,因为我在互操作层中看到了一个例外。 (System.Runtime.InteropServices.SafeArrayTypeMismatchException)。

显然,预计类型似乎存在差异。

在此处粘贴代码:

要调用的C#方法:

public long DoIt3(int nFiles, string[] fileNames);

调用C ++代码:

int _tmain()
{
TCHAR *fileNames[128] = { TEXT("C:\\Program Files\\IBM\\RTC.NET"),
                          TEXT("C:\\KIRAN\\Work\\RFT"), TEXT(".\\bin\\Debug") };

SAFEARRAY *pSA = CreateSafeStringArray(3, fileNames);

_tprintf(TEXT("%d"), pIManaged->DoIt3(3, pSA));

SafeArrayDestroy(pSA);
}

static SAFEARRAY *CreateSafeStringArray(long nElements, TCHAR *elements[])
{
SAFEARRAYBOUND saBound[1];

saBound[0].cElements = nElements;
saBound[0].lLbound = 0;

SAFEARRAY *pSA = SafeArrayCreate(VT_VARIANT, 1, saBound);

if (pSA == NULL)
{
    return NULL;
}

for (int ix = 0; ix < nElements; ix++)
{
    VARIANT v;

    VariantInit(&v);

    v.vt = VT_BSTR;
    v.bstrVal = elements[ix];

    long rgIndicies[1];

    rgIndicies[0] = ix + saBound[0].lLbound;

    HRESULT hr = SafeArrayPutElement(pSA, rgIndicies, &v);

    _tprintf(TEXT("%d"), hr);

    VariantClear(&v);
}

return pSA;
}

欢迎任何想法/建议。

2 个答案:

答案 0 :(得分:1)

对于BSTR字符串数组,您可以直接在数组上设置BSTR值,还可以you need to allocate memory for your BSTR elements,您可以使用ATL / MFC CString:

...
psa = SafeArrayCreate( VT_BSTR, 1, saBound);
HRESULT hr = SafeArrayLock( psa );
//TODO: test for hr success

if (pSA == NULL)
{
    return NULL;
}

for (int ix = 0; ix < nElements; ix++)
{
    long rgIndicies[1];
    rgIndicies[0] = ix + saBound[0].lLbound;
    CString tempstr(elements[ix]);

    ((BSTR*)psa->pvData)[ix] = tempstr.AllocSysString();
    _tprintf(TEXT("%d"), hr);
}

hr = SafeArrayUnlock( psa );
//TODO: test for hr success
...

答案 1 :(得分:1)

我明白了!以下代码有效:

static SAFEARRAY *CreateSafeStringArray(long nElements, TCHAR *elements[])
{
SAFEARRAYBOUND saBound[1];

saBound[0].cElements = nElements;
saBound[0].lLbound = 0;

SAFEARRAY *pSA = SafeArrayCreate(VT_BSTR, 1, saBound);

if (pSA == NULL)
{
    return NULL;
}

for (int ix = 0; ix < nElements; ix++)
{
    BSTR pData = SysAllocString(elements[ix]);

    long rgIndicies[1];

    rgIndicies[0] = saBound[0].lLbound + ix;

    HRESULT hr = SafeArrayPutElement(pSA, rgIndicies, pData);

    _tprintf(TEXT("%d"), hr);
}

return pSA;
}

感谢你的所有建议!