fltk-rs如何捕获特定按键

Rust语言
这里演示了使用handle函数捕获“E”和向下键。

use fltk::{prelude::*,*, window::Window, app::event_key};

fn main() {
    let app = app::App::default().with_scheme(app::Scheme::Gleam);
    let mut wind = Window::default().with_size(100, 100);
    let mut frame = frame::Frame::default();
    frame.handle(move |_, event |match event {
        enums::Event::KeyUp => {
            if app::event_key() == enums::Key::from_char('e'){
                println!("E Up");
            }
            if app::event_key() == enums::Key::Down{
                println!("Down Up");
            }
            true
        }
        _ => false
    });
    wind.end();
    wind.show();
    app.run().unwrap();
}