LVGL 8.2 meter控件实现模拟时钟

动画回调函数

static lv_obj_t* meter;
static void set_value(void* indic, int32_t v)
{
    lv_meter_set_indicator_end_value(meter, indic, v); // 设置分针值
}
static void set_hour_value(void* indic, int32_t v)
{
    if (v == 0)
        v = 12;
    lv_meter_set_indicator_end_value(meter, indic, v);   // 设置时针值
}

clock from a meter

static void lv_example_meter_3(void)
{
    meter = lv_meter_create(lv_scr_act());
    lv_obj_set_size(meter, 220, 220);
    lv_obj_center(meter);

    lv_obj_remove_style(meter, NULL, LV_PART_TICKS);
    lv_obj_remove_style(meter, NULL, LV_PART_ITEMS);
    /*Create a scale for the minutes*/
    /*61 ticks in a 360 degrees range (the last and the first line overlaps)*/
    lv_meter_scale_t* scale_min = lv_meter_add_scale(meter);
    lv_meter_set_scale_ticks(meter, scale_min, 61, 1, 10, lv_palette_main(LV_PALETTE_GREY));
    lv_meter_set_scale_range(meter, scale_min, 0, 60, 360, 270);
    /*Create another scale for the hours. It's only visual and contains only major ticks*/
    lv_meter_scale_t* scale_hour = lv_meter_add_scale(meter);
    lv_meter_set_scale_ticks(meter, scale_hour, 12, 0, 0, lv_palette_main(LV_PALETTE_GREY)); /*12 ticks*/
    lv_meter_set_scale_major_ticks(meter, scale_hour, 1, 2, 20, lv_color_black(), 10); /*Every tick is major*/
        lv_meter_set_scale_range(meter, scale_hour, 1, 12, 330, 300); /*[1..12] values in an almost full circle*/
    LV_IMG_DECLARE(img_hand)  // 表针图片资源声明
        /*Add a the hands from images*/
        lv_meter_indicator_t* indic_min = lv_meter_add_needle_img(meter, scale_min, &img_hand, 5, 5); // 
    lv_meter_indicator_t* indic_hour = lv_meter_add_needle_img(meter, scale_hour, &img_hand, 5, 5);
    /*Create an animation to set the value*/
    lv_anim_t a;
    lv_anim_init(&a);
    lv_anim_set_exec_cb(&a, set_value);
    lv_anim_set_values(&a, 0, 60);
    lv_anim_set_repeat_count(&a, LV_ANIM_REPEAT_INFINITE);
    lv_anim_set_time(&a, 2000); /*2 sec for 1 turn of the minute hand (1 hour)*/
    lv_anim_set_var(&a, indic_min);
    lv_anim_start(&a);

    lv_anim_t a1;
    lv_anim_init(&a1);
    lv_anim_set_exec_cb(&a1, set_hour_value);
    lv_anim_set_repeat_count(&a1, LV_ANIM_REPEAT_INFINITE);
    lv_anim_set_var(&a1, indic_hour);
    lv_anim_set_time(&a1, 24000); /*24 sec for 1 turn of the hour hand*/
    lv_anim_set_values(&a1, 0, 12);
    lv_anim_start(&a1);
}

运行效果