What is the proper #include for the InputKeyboardSourceEventArgs ?

[shelllet]

i want to hook the escape key for contentdialog, so i found the flowing code:

class RespondToKeyDown
{
    InputKeyboardSource myInputKeyboardSource;

    public RespondToKeyDown(Microsoft.UI.Content.ContentIsland island)
    {
        myInputKeyboardSource = InputKeyboardSource.GetForIsland(island);
        myInputKeyboardSource.KeyDown += OnKeyDown;
    }

    void OnKeyDown(
        InputKeyboardSource sender,
        InputKeyboardSourceEventArgs args)
    {
        if (args.VirtualKey == Windows.System.VirtualKey.Escape)
        {
            System.Diagnostics.Debug.WriteLine("Escape key was pressed.");
            CancelCurrentOperation();
            args.Handled = true;
        }
    }
}

but i can't find the the type of InputKeyboardSourceEventArgs ,
how did i find where is the type of InputKeyboardSourceEventArgs declared in windowsappsdk winrt/c++?

and how can i do to hook the escape key for contentdialog?

[DarranRowe]

Well, the most important thing to note here is that the sample is wrong in regards to the InputKeyboardSourceEventArgs type.

The documentation for the KeyDown event shows that what it has is a Microsoft.UI.Input.KeyEventArgs parameter. This is also reflected in the C++/WinRT headers.

int32_t __stdcall add_KeyDown(void* handler, winrt::event_token* token) noexcept final try
        {
            zero_abi<winrt::event_token>(token);
            typename D::abi_guard guard(this->shim());
            *token = detach_from<winrt::event_token>(this->shim().KeyDown(*reinterpret_cast<winrt::Windows::Foundation::TypedEventHandler<winrt::Microsoft::UI::Input::InputKeyboardSource, winrt::Microsoft::UI::Input::KeyEventArgs> const*>(&handler)));
            return 0;
        }
        catch (...) { return to_hresult(); }

Notice the reinterpret_cast's type that it is converting to.