COM访问Windows桌面最佳实践案例C++源代码

//#define _WIN32_DCOM //如果出现CoCreateInstance失败,可以尝试打开此项
//#define _WIN32_IE 0x0500 //如果出现方法E_NOIMPL,可以尝试打开此项
#include <atlstr.h>
#include <wininet.h>
#include <shlobj.h>

class CComMgr {
public:
    CComMgr() {
        (void)::CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);
    }
    ~CComMgr() {
        (void)::CoUninitialize();
    }
public:
    void test()
    {
        WCHAR   wszWallpaper[MAX_PATH];
        CString strPath;
        HRESULT hr;
        IActiveDesktop* pIAD;
        //hr = ::CoInitialize(NULL);
        //hr = ::CoInitializeEx(NULL, COINIT_MULTITHREADED);
        // 2. 使用外壳提供的活动桌面组件对象类创建COM对象。
        // 第四个参数通知COM需要什么接口(这里是IActiveDesktop).
        hr = CoCreateInstance(CLSID_ActiveDesktop,
            NULL,
            CLSCTX_INPROC_SERVER,
            IID_IActiveDesktop,
            (void**)&pIAD);
        if (SUCCEEDED(hr))
        {
            // 3. 如果COM对象被创建成功，则调用这个对象的GetWallpaper() 方法。
            hr = pIAD->GetWallpaper(wszWallpaper, MAX_PATH, 0);
            if (SUCCEEDED(hr))
            {
                // 4. 如果 GetWallpaper() 成功，则输出它返回的文件名字。
               // 注意这里使用wcout 来显示Unicode 串wszWallpaper. wcout 是
               // Unicode 专用，功能与cout.相同。
                std::cout << L"Wallpaper pathis:\n    " << CStringA(wszWallpaper) << std::endl;
            }
            else
            {
                std::cout << _T("GetWallpaper()failed.") << std::endl;
            }
            // 5. 释放接口。
            pIAD->Release();
        }
        else
        {
            std::cout << _T("CoCreateInstance()failed.") << std::endl;
        }
        //::CoUninitialize();
    }
    void addItemToDesktop()
    {
        HRESULT hr;
        IActiveDesktop* pActiveDesktop;
        COMPONENT compDesktopItem;

        //Create an instance of the Active Desktop
        hr = CoCreateInstance(CLSID_ActiveDesktop, NULL, CLSCTX_INPROC_SERVER,
            IID_IActiveDesktop, (void**)&pActiveDesktop);

        // Initialize the COMPONENT structure
        compDesktopItem.dwSize = sizeof(COMPONENT);

        // Insert code that adds the information about the desktop item 
        // to the COMPONENT structure
        wcscpy(compDesktopItem.wszFriendlyName, L"Test");
        // Add the desktop item
        hr = pActiveDesktop->AddDesktopItem(&compDesktopItem, 0);

        // Save the changes to the registry
        hr = pActiveDesktop->ApplyChanges(AD_APPLY_ALL);

        pActiveDesktop->Release();
    }
    void enumItemDesktop() {
        HRESULT hr;
        IActiveDesktop* pActiveDesktop;
        COMPONENT compDesktopItem;
        int intCount;
        int intIndex = 0;

        //Create an instance of the Active Desktop
        hr = CoCreateInstance(CLSID_ActiveDesktop, NULL, CLSCTX_INPROC_SERVER,
            IID_IActiveDesktop, (void**)&pActiveDesktop);

        hr = pActiveDesktop->GetDesktopItemCount(&intCount, 0);

        compDesktopItem.dwSize = sizeof(COMPONENT);

        while (intIndex <= (intCount - 1))
        {
            //get the COMPONENT structure for the current desktop item
            hr = pActiveDesktop->GetDesktopItem(intIndex, &compDesktopItem, 0);

            //Insert code that processes the structure
            std::cout << CStringA(compDesktopItem.wszFriendlyName) << std::endl;
            std::cout << CStringA(compDesktopItem.wszSource) << std::endl;
            std::cout << CStringA(compDesktopItem.wszSubscribedURL) << std::endl;
            //Increment the index
            intIndex++;

            //Insert code to clean-up structure for next component
        }

        // Call the Release method
        pActiveDesktop->Release();
    }
public:
    static CComMgr* Inst() {
        static CComMgr CComMgrInstance;
        return &CComMgrInstance;
    }
};