为 CFAPI 设置状态图标无法按预期工作答案

【问题标题】：Setting Status icon for CFAPI does not work as expected为 CFAPI 设置状态图标无法按预期工作
【发布时间】：2021-04-15 10:13:04
【问题描述】：

我尝试将使用 CFAPI 创建的占位符文件的状态图标设置为错误。（见下文）

文件夹T的内容：

我在文件上设置了错误状态，但它没有显示错误。但是错误会显示在包含的文件夹中。

我使用以下代码对文件设置错误（完整代码发布在github）：

void SetTransferStatus(_In_ PCWSTR fullPath, _In_ SYNC_TRANSFER_STATUS status)
{
    // Tell the Shell so File Explorer can display the progress bar in its view
    try
    {
        // First, get the Volatile property store for the file. That's where the properties are maintained.
        winrt::com_ptr<IShellItem2> shellItem;
        winrt::check_hresult(SHCreateItemFromParsingName(fullPath, nullptr, __uuidof(shellItem), shellItem.put_void()));

        winrt::com_ptr<IPropertyStore> propStoreVolatile;
        winrt::check_hresult(
            shellItem->GetPropertyStore(
                GETPROPERTYSTOREFLAGS::GPS_READWRITE | GETPROPERTYSTOREFLAGS::GPS_VOLATILEPROPERTIESONLY,
                __uuidof(propStoreVolatile),
                propStoreVolatile.put_void()));

        // Set the sync transfer status accordingly
        PROPVARIANT transferStatus;
        winrt::check_hresult(
            InitPropVariantFromUInt32(
                status,
                &transferStatus));
        winrt::check_hresult(propStoreVolatile->SetValue(PKEY_SyncTransferStatus, transferStatus));

        // Without this, all your hard work is wasted.
        winrt::check_hresult(propStoreVolatile->Commit());

        // Broadcast a notification that something about the file has changed, so that apps
        // who subscribe (such as File Explorer) can update their UI to reflect the new progress
        SHChangeNotify(SHCNE_UPDATEITEM, SHCNF_PATH, static_cast<LPCVOID>(fullPath), nullptr);

        //wprintf(L"Succesfully Set Transfer Progress on \"%s\" to %llu/%llu\n", fullPath, completed, total);
    }
    catch (...)
    {
        // winrt::to_hresult() will eat the exception if it is a result of winrt::check_hresult,
        // otherwise the exception will get rethrown and this method will crash out as it should
        wprintf(L"Failed to Set Transfer Progress on \"%s\" with %08x\n", fullPath, static_cast<HRESULT>(winrt::to_hresult()));
    }
}

此外，如果我删除文件并创建一个新文件，状态仍然会出错。

【问题讨论】：

嗨，我现在可以重现此问题。我会与内部工程师确认，如果有任何更新，请在此处回复。感谢您的理解。
您好，您能解释一下为什么IPropertyStore::SetValue 函数会设置状态。我认为这是问题的原因。我想你可以参考official sample来实现你的需求。
@SongZhu-MSFT 我对那个链接很感兴趣，但它似乎被破坏了:(页面底部显示Error:null|403
抱歉，是我造成的错误。可以参考：CloudMirror
@SongZhu-MSFT 感谢我的项目基于示例。但是错误状态的设置不在示例中。您可以设置其他图标，但不能将第一个图标设置为错误状态。我想我在示例中没有看到这样的代码

标签： c++ windows winapi minifilter

【解决方案1】：

有人将我指向 Windows 云镜像示例中的 pull request，它显示了如何完成此操作。

这是代码：

void Utilities::UpdateErrorOnItem(PCWSTR path, bool setError)
{
    try
    {
        winrt::com_ptr<IShellItem2> item;
        winrt::check_hresult(SHCreateItemFromParsingName(path, nullptr, IID_PPV_ARGS(item.put())));

        winrt::com_ptr<IPropertyStore> propertyStore;
        winrt::check_hresult(item->GetPropertyStore(GPS_READWRITE | GPS_EXTRINSICPROPERTIESONLY, IID_PPV_ARGS(propertyStore.put())));

        PROPVARIANT propVar{};
        if (setError)
        {
            propVar.vt = VT_UI4;
            propVar.ulVal = static_cast<unsigned long>(E_FAIL);
            winrt::check_hresult(propertyStore->SetValue(PKEY_LastSyncError, propVar));
        }
        else
        {
            // Clear by setting to empty
            propVar.vt = VT_EMPTY;
            winrt::check_hresult(propertyStore->SetValue(PKEY_LastSyncError, propVar));
        }

        winrt::check_hresult(propertyStore->Commit());
    }
    catch (...)
    {
        // winrt::to_hresult() will eat the exception if it is a result of winrt::check_hresult,
        // otherwise the exception will get rethrown and this method will crash out as it should
        wprintf(L"Failed to set error state with %08x\n", static_cast<HRESULT>(winrt::to_hresult()));
    }

【讨论】：