覆盖RichEditBox上的键盘快捷键？

Question

Is there a way to disable, or better yet override, keyboard shortcuts on the WinRT RichEditBox control? I want to be able to disable the bold and italic formatting when you press Ctrl-B and Ctrl-I.

I'm avoiding using a regular plain TextBox because I want to use the formatting options in the RichEditBox to add syntax highlighting to the text. If the user can manipulate the styling within the box, that won't work.

Thank you!

Answer 1

At long last I found the answer in another question : the OnKeyDown method of a text control gets called before the KeyDown event is fired, so rather than listening to the KeyDown event, you must create a subclass of RichEditBox and override the OnKeyDown method. Then in your XAML markup or wherever you're instantiating the RichEditBox , use your custom subclass instead. As a somewhat-related example, I created an override of TextBox that prevents undo and redo operations:

[Windows::Foundation::Metadata::WebHostHidden]
public ref class BetterTextBox sealed : public Windows::UI::Xaml::Controls::TextBox
{
public:
    BetterTextBox() {}
    virtual ~BetterTextBox() {}
    virtual void OnKeyDown(Windows::UI::Xaml::Input::KeyRoutedEventArgs^ e) override
    {
        Windows::System::VirtualKey key = e->Key;
        Windows::UI::Core::CoreVirtualKeyStates ctrlState = Windows::UI::Core::CoreWindow::GetForCurrentThread()->GetKeyState(Windows::System::VirtualKey::Control);
        if ((key == Windows::System::VirtualKey::Z || key == Windows::System::VirtualKey::Y) &&
            ctrlState != Windows::UI::Core::CoreVirtualKeyStates::None)
        {
            e->Handled = true;
        }

        // only call the base implementation if we haven't already handled the input
        if (!e->Handled)
        {
            Windows::UI::Xaml::Controls::TextBox::OnKeyDown(e);
        }
    }
};