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我正在使用 COM 库“Microsoft Scripting Runtime”（c:\windows\System32\scrrun.dll）中的 Scripting.Dictionary。我正在使用 import 来获取我的包装器，这些都在工作。添加一些项目后，我试图获取键列表，但我被卡住了。

我有办法。我可以从SAFEARRAYDictionary 中获取 of 键，但我想使用CComSafeArray定义的类，<atlsafe.h>但我无法找到一个好的结构。目前，构造函数抛出一个ATL抱怨vartype不匹配的断言。诚然，新构建的 CComSafeArray 有vartype52428 个十六进制的 CCCC，这看起来可能像未初始化的内存。但是推断的类型看起来也不正确，我希望安全数组的 vartype 是字符串，但断言代码给出了 vartype 12，即 UI2。很奇怪。

无论如何，这对于熟悉这一点的人来说可能很容易。这是一个符合 SO 标准的控制台程序 Minimal, Complete, Verifiable, Example (MCVE)。

#include "stdafx.h"
#include <atlbase.h>
#include <atlsafe.h>

#import "c:\windows\System32\scrrun.dll" raw_interfaces_only,raw_native_types, named_guids, rename("DeleteFile", "_DeleteFile"), rename("MoveFile","_MoveFile"), rename("CopyFile", "_CopyFile"), rename("GetFreeSpace", "_GetFreeSpace")

int main()
{
    HRESULT hr = S_OK;

    CoInitialize(0);

    CComQIPtr<Scripting::IDictionary> dictColours;
    hr = dictColours.CoCreateInstance(__uuidof(Scripting::Dictionary));
    if (!SUCCEEDED(hr)) { return hr; }

    CComVariant varZero(0); //dummy value, only interested in keys

    hr = dictColours->Add(&variant_t(L"red"), &varZero);
    if (!SUCCEEDED(hr)) { return hr; }

    hr = dictColours->Add(&variant_t(L"green"), &varZero);
    if (!SUCCEEDED(hr)) { return hr; }

    hr = dictColours->Add(&variant_t(L"blue"), &varZero);
    if (!SUCCEEDED(hr)) { return hr; }

    long lColourCount(0);
    hr = dictColours->get_Count(&lColourCount);
    if (!SUCCEEDED(hr)) { return hr; }

    CComVariant varColoursKeys;
    hr = dictColours->Keys(&varColoursKeys);
    if (!SUCCEEDED(hr)) { return hr; }

    SAFEARRAY keys(*(varColoursKeys.parray));

    //fine up to this point

    CComSafeArray<VARIANT> varColours;

    /* The following code throws an error for the next (line) live, vt=52428 or hex CCCC which looks like uninitialised memory
       whilst GetType() returns 12 which is UI2 (and somehow I expected string type 8!) 
    VARTYPE vt;
    HRESULT hRes = ::ATL::AtlSafeArrayGetActualVartype(const_cast<LPSAFEARRAY>(psaSrc), &vt);
    ATLENSURE_SUCCEEDED(hRes);
    ATLENSURE_THROW(vt == GetType(), E_INVALIDARG);
    */

    varColours = (keys);

    CoUninitialize();
    return 0;
}
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1 回答 1

2

改变这个：

SAFEARRAY keys(*(varColoursKeys.parray));

对此：

SAFEARRAY* keys = varColoursKeys.parray;

（可选，首先确保varColoursKeys.vt有VT_ARRAY标志）

然后你可以查询keys它的vt：

hr = ::ATL::AtlSafeArrayGetActualVartype(keys, &vt);

请注意，这varColours = keys将复制数组数据。如果这不是你真正想要的，那么你应该Detach()从CComVariant（或者直接使用VARIANT而不是直接使用CComVariant）和Attach()它到CComSafeArray（然后你可以使用该CComSafeArray::GetType()方法）的数组。

此外，在调用CoUninitialize().

试试这个：

#include "stdafx.h"
#include <atlbase.h>
#include <atlsafe.h>

#import "c:\windows\System32\scrrun.dll" raw_interfaces_only,raw_native_types, named_guids, rename("DeleteFile", "_DeleteFile"), rename("MoveFile","_MoveFile"), rename("CopyFile", "_CopyFile"), rename("GetFreeSpace", "_GetFreeSpace")

HRESULT DoIt()
{
    CComQIPtr<Scripting::IDictionary> dictColours;
    hr = dictColours.CoCreateInstance(__uuidof(Scripting::Dictionary));
    if (FAILED(hr)) { return hr; }

    CComVariant varZero(0); //dummy value, only interested in keys

    hr = dictColours->Add(&variant_t(L"red"), &varZero);
    if (FAILED(hr)) { return hr; }

    hr = dictColours->Add(&variant_t(L"green"), &varZero);
    if (FAILED(hr)) { return hr; }

    hr = dictColours->Add(&variant_t(L"blue"), &varZero);
    if (FAILED(hr)) { return hr; }

    long lColourCount(0);
    hr = dictColours->get_Count(&lColourCount);
    if (FAILED(hr)) { return hr; }

    VARIANT varColoursKeys;
    hr = dictColours->Keys(&varColoursKeys);
    if (FAILED(hr)) { return hr; }

    CComSafeArray<VARIANT> varColours;
    varColours.Attach(varColoursKeys.parray);

    // use varColours as needed...

    VARTYPE vt = varColours.GetType();

    LONG lLower = varColours.GetLowerBound();
    LONG lUpper = varColours.GetUpperBound();
    for (LONG i = lLower; i <= lUpper; ++i)
    {
        VARIANT &v = varColours.GetAt(i);
        // use v.bstrVal as needed ...
    }

    //...

    return S_OK;
}

int main()
{
    HRESULT hr = CoInitialize(0);
    if (FAILED(hr)) { return hr; }

    hr = DoIt();

    CoUninitialize();
    return hr;
}
于 2018-04-02T22:52:31.067 回答