无法激活 IDL 中定义的投影类型

Question

我试图在 IDL 中定义一个 Windows 运行时类型，并使用它的投影类型。从 default-generated Blank App UWP 项目（称为 "Blank App"）开始，我添加了 "MyControl.idl":

namespace BlankApp
{
    [default_interface]
    runtimeclass MyControl : Windows.UI.Xaml.Controls.Control
    {
        MyControl();
    }
}

编译解决方案，然后从复制MyControl.h和MyControl.cpp生成Files/sources到项目根目录。

我为投影类型添加了 header 并将以下代码添加到 App::OnLaunched:

#include <winrt/BlankApp.h>

...

void App::OnLaunched(LaunchActivatedEventArgs const& e)
{
    auto const myControl{ winrt::BlankApp::MyControl() };
    ...

这一切编译和链接都很好。在运行时，它抛出一个 hresult_error (0x80040154: REGDB_E_CLASSNOTREG Class not registered).

引发异常时的调用堆栈顶部如下所示：

BlankApp.exe!winrt::hresult_error::hresult_error(const HRESULT code=REGDB_E_CLASSNOTREG Class not registered, winrt::hresult_error::from_abi_t __formal={...}) Line 2977  C++ Symbols loaded.
BlankApp.exe!winrt::throw_hresult(const HRESULT result=REGDB_E_CLASSNOTREG Class not registered) Line 3211  C++ Symbols loaded.
BlankApp.exe!winrt::check_hresult(HRESULT result=REGDB_E_CLASSNOTREG Class not registered) Line 3261    C++ Symbols loaded.
BlankApp.exe!winrt::impl::get_activation_factory<winrt::BlankApp::MyControl,winrt::Windows::Foundation::IActivationFactory>() Line 7375 C++ Symbols loaded.
BlankApp.exe!winrt::impl::factory_cache_entry<winrt::BlankApp::MyControl,winrt::Windows::Foundation::IActivationFactory>::get() Line 7448   C++ Symbols loaded.
BlankApp.exe!winrt::get_activation_factory<winrt::BlankApp::MyControl,winrt::Windows::Foundation::IActivationFactory>() Line 7520   C++ Symbols loaded.
BlankApp.exe!winrt::BlankApp::MyControl::MyControl() Line 74    C++ Symbols loaded.
BlankApp.exe!winrt::BlankApp::implementation::App::OnLaunched(const winrt::Windows::ApplicationModel::Activation::LaunchActivatedEventArgs & e={...}) Line 50   C++ Symbols loaded.

module.g.cpp 被编译到应用程序中并包含以下代码：

HRESULT __stdcall WINRT_GetActivationFactory(HSTRING classId, void** factory)
{
    try
    {
        *factory = nullptr;
        wchar_t const* const name = WindowsGetStringRawBuffer(classId, nullptr);

        if (0 == wcscmp(name, L"BlankApp.MainPage"))
        {
            *factory = winrt::detach_abi(winrt::make<winrt::BlankApp::factory_implementation::MainPage>());
            return S_OK;
        }

        if (0 == wcscmp(name, L"BlankApp.MyControl"))
        {
            *factory = winrt::detach_abi(winrt::make<winrt::BlankApp::factory_implementation::MyControl>());
            return S_OK;
        }

#ifdef _WRL_MODULE_H_
        return ::Microsoft::WRL::Module<::Microsoft::WRL::InProc>::GetModule().GetActivationFactory(classId, reinterpret_cast<::IActivationFactory**>(factory));
#else
        return winrt::hresult_class_not_available().to_abi();
#endif
    }
    catch (...)
    {
        return winrt::to_hresult();
    }
}

很显然，Windows 运行时未注册我的类型以进行查找，尽管一切似乎都在需要的位置。我缺少一些注册步骤吗？或者 UWP 应用程序是否支持此功能而不是 Windows 运行时组件？

Answer 1

您可能需要将 class 添加到 appx 清单。

Extensions element documentation. The following Extension元素中有一个例子需要添加：

<Extensions>
  <Extension Category="windows.activatableClass.inProcessServer">
    <InProcessServer>
      <Path>BlankApp.exe</Path>
      <ActivatableClass ActivatableClassId="BlankApp.MyControl" ThreadingModel="both" />
    </InProcessServer>
  </Extension>
</Extensions>

要允许 Windows 运行时检索激活工厂，还需要从可执行文件中导出 DllGetActivationFactory 符号。这可以通过将以下 .def 文件添加到项目中来完成：

EXPORTS
DllCanUnloadNow = WINRT_CanUnloadNow                    PRIVATE
DllGetActivationFactory = WINRT_GetActivationFactory    PRIVATE

无法激活 IDL 中定义的投影类型

Can't activate projected type defined in IDL

uwp

windows-runtime

c++-winrt