lvgl/examples/event/lv_example_event_click.c

#include "../lv_examples.h"
#if LV_BUILD_EXAMPLES && LV_USE_SWITCH

static void event_cb(lv_event_t * e)
{
    LV_LOG_USER("Clicked");

    static uint32_t cnt = 1;
    lv_obj_t * btn = lv_event_get_target_obj(e);
    lv_obj_t * label = lv_obj_get_child(btn, 0);
    lv_label_set_text_fmt(label, "%" LV_PRIu32, cnt);
    cnt++;
}

/**
 * @title Click event on a button
 * @brief Update a button's label with an incrementing counter on each click.
 *
 * A button with a child label is placed on the active screen. An
 * `LV_EVENT_CLICKED` callback retrieves the button, updates its label with
 * a static incrementing counter, and logs `Clicked`.
 */
void lv_example_event_click(void)
{
    lv_obj_t * btn = lv_button_create(lv_screen_active());
    lv_obj_set_size(btn, 100, 50);
    lv_obj_center(btn);
    lv_obj_add_event_cb(btn, event_cb, LV_EVENT_CLICKED, NULL);

    lv_obj_t * label = lv_label_create(btn);
    lv_label_set_text(label, "Click me!");
    lv_obj_center(label);
}

#endif