C++ Msi函数判断应用是否已经安装

#include <Windows.h>  
#include <Msi.h>  
#pragma comment(lib, "Msi.lib")  

bool CheckExistSoftware(wchar_t *upgradeCode)  //可以通过工具Orca查看安装包相应的upgradeCode  
{  
    wchar_t productCode[39];  
    if (ERROR_SUCCESS == MsiEnumRelatedProductsW(upgradeCode, 0, 0, productCode))  
    {  
        return true;  
    }  
    return false;  
}  

void GetSoftwareInstallPath(const wchar_t *upgradeCode, wchar_t *installPath, DWORD *pathLength)  
{  
    DWORD i = 0;  
    UINT result;  
    wchar_t productCode[39];  
    for (i = 0; ERROR_NO_MORE_ITEMS != (result = MsiEnumRelatedProductsW(upgradeCode, 0, i, productCode)); i++)  
    {  
        if (ERROR_SUCCESS == result)  
        {  
            if (ERROR_SUCCESS == MsiGetProductInfoW(productCode, INSTALLPROPERTY_INSTALLLOCATION, installPath, pathLength))  
            {  
                return;  
            }  
        }  
    }  
    wcscpy_s(installPath, 2, L"");  
}