如何在bevy中读取鼠标运动？

use bevy::prelude::*;

fn main() {
    App::build()
        .add_plugins(DefaultPlugins)
        .add_startup_system(setup.system())
        .add_system(mouse_movement.system())
        .run();
}

fn setup(commands: &mut Commands) {
    commands.spawn(Camera2dBundle::default());
}

fn mouse_movement(
    windows: Res<Windows>,
    mut mouse_events: EventReader<CursorMoved>,
) {
    for event in mouse_events.iter() {
        if let Some(window) = windows.get(event.id) {
            let position = window.cursor_position();
            println!("Mouse position: {:?}", position);
        }
    }
}