bevy/examples/input/char_input_events.rs

use bevy::{prelude::*, window::ReceivedCharacter};

fn main() {
    App::build()
        .add_plugins(DefaultPlugins)
        .add_system(print_char_event_system)
        .run();
}

#[derive(Default)]
struct State {
    event_reader: EventReader<ReceivedCharacter>,
}

/// This system prints out all char events as they come in
fn print_char_event_system(
    mut state: Local<State>,
    char_input_events: Res<Events<ReceivedCharacter>>,
) {
    for event in state.event_reader.iter(&char_input_events) {
        println!("{:?}: '{}'", event, event.char);
    }
}