C++ - MsiSummaryInfoGetProperty

Question

我完全不懂这个，所以需要一些帮助。我正在尝试使用 MsiGetSummaryInformation和 MsiSummaryInfoGetProperty

我不是 C++ 背景的，所以您必须多多包涵。这是我的尝试:

    UINT sisStatus = MsiGetSummaryInformation(0,originalTransform,0,&sumh);
    //UINT sisStatus = MsiGetSummaryInformation(hDbObject,0,0,&sumh);
    if (ERROR_SUCCESS == sisStatus)
    {
        //success - start getting/setting SIS
        //UINT property_type = VT_LPSTR;

        UINT pcount;
        MsiSummaryInfoGetPropertyCount(sumh,&pcount);
        wcout << "PCount " << pcount << endl;

        UINT getpropertyid = 2; 
        UINT returnpropertyid;      
        int returnedIntPropData;
        FILETIME fileValPtr;     
        LPDWORD stringDataLength = 0;           
        LPWSTR propdata = L"";

        MsiSummaryInfoGetProperty(sumh,getpropertyid,&returnpropertyid,&returnedIntPropData,&fileValPtr,propdata, stringDataLength);

        wcout << "Propdata " << propdata << endl;
        wcout << "Stringlength " << stringDataLength << endl;


    }

但它似乎并没有起作用。返回的值似乎不正确。任何人都可以解释一下吗？

更新

这是我的新(更新)示例:

UINT getpropertyid = 2; 
        UINT returnpropertyid;      
        int returnedIntPropData;
        FILETIME fileValPtr;     
        LPDWORD stringDataLength = new DWORD();     
        LPWSTR propdata = new TCHAR[];

        UINT gps = MsiSummaryInfoGetProperty(sumh,getpropertyid,&returnpropertyid,&returnedIntPropData,&fileValPtr,propdata, stringDataLength);
        if (ERROR_SUCCESS == gps)
        {
            wcout << "RETURN CODE: " << gps << endl;

        wcout << "Propdata " << propdata << endl;
        wcout << "Stringlength " << stringDataLength << endl;
         }
        else
        {
            wcout << "RETURN CODE EXPAND: " << gps << endl;             

            int num = (int)stringDataLength;
            wcout << "Buffer size: " << num << endl;

            propdata = new TCHAR[num];
            stringDataLength = new DWORD(num);  

            MsiSummaryInfoGetProperty(sumh,getpropertyid,&returnpropertyid,&returnedIntPropData,&fileValPtr,propdata, stringDataLength);

            wcout << "Propdata " << propdata << endl;
            wcout << "Stringlength " << stringDataLength << endl;   


        }

这一行:wcout << "缓冲区大小:"<< num << endl;

返回3873856，好像有点大？我认为我的编码有点困惑。你的例子会很有帮助!

Answer 1

避免调用new；如果你真的不知道自己在做什么，那会让你陷入痛苦的世界。而是传递您已经分配的存储地址(例如，通过声明本地整数值，或在缓冲区中为 std::wstring)。我已经修改了您的第一个示例，使其更符合我的编写方式，尽管我很少会在使用 wcout 的地方结束。 (请注意，originalTransform 和硬编码的 uiProperty 仍然有一个悬挂变量。)

PMSIHANDLE hSum;
DWORD dwErr = MsiGetSummaryInformation(0, originalTransform, 0, &hSum);
if (ERROR_SUCCESS == dwErr)
{
    UINT uiProperty = 2;
    UINT uiDataType = 0;
    INT iValue = 0;
    FILETIME ftValue = {0};
    std::wstring sValue;
    DWORD cchValue = MAX_PATH;
    sValue.resize(cchValue);
    dwErr = MsiSummaryInfoGetProperty(hSum, uiProperty, &uiDataType, &iValue, &ftValue, const_cast<LPWSTR>(sValue.data()), &cchValue);
    if (ERROR_MORE_DATA == dwErr)
    {
        sValue.resize(++cchValue);
        dwErr = MsiSummaryInfoGetProperty(hSum, uiProperty, &uiDataType, &iValue, &ftValue, const_cast<LPWSTR>(sValue.data()), &cchValue);
    }
    if (ERROR_SUCCESS == dwErr)
    {
        sValue.resize(cchBuf);
        if (VT_LPSTR == uiDataType)
            wcout << "String Data (" << cchBuf << "): " << sValue << "\n";
        else if (VT_I4 == uiDataType)
            wcout << "Numeric Data: " << iValue << "\n";
    }
    else
    {
        wcout << "Error retrieving property: " << dwErr << "\n";
    }
}
else
{
    wcout << "Error retrieving summary info: " << dwErr << "\n";
}