LVGL 8.2 meter

动画播放回调函数

static lv_obj_t* meter;
static void set_value(void* indic, int32_t v)
{
    lv_meter_set_indicator_value(meter, indic, v);  // 设置表头指示值
}

创建meter

static void lv_example_meter_1(void)
{
    meter = lv_meter_create(lv_scr_act()); // 创建meter对象
    lv_obj_center(meter);  // 居中显示
    lv_obj_set_size(meter, 200, 200);  // 设置大小
    /*Add a scale first*/
    lv_meter_scale_t* scale = lv_meter_add_scale(meter); // 增加表刻度
    lv_meter_set_scale_ticks(meter, scale, 41, 2, 10, lv_palette_main(LV_PALETTE_GREY)); // 设置ticks
    lv_meter_set_scale_major_ticks(meter, scale, 8, 4, 15, lv_color_black(), 10); // 设置major ticks
    lv_meter_indicator_t* indic;
    /*Add a blue arc to the start*/
    indic = lv_meter_add_arc(meter, scale, 3, lv_palette_main(LV_PALETTE_BLUE), 0); //添加蓝色表弧指示
    lv_meter_set_indicator_start_value(meter, indic, 0); // 起始指示值0
    lv_meter_set_indicator_end_value(meter, indic, 20); // 结束指示值20
    /*Make the tick lines blue at the start of the scale*/
    indic = lv_meter_add_scale_lines(meter, scale, lv_palette_main(LV_PALETTE_BLUE), lv_palette_main(LV_PALETTE_BLUE), 
        false, 0);// 添加蓝色刻度线
    lv_meter_set_indicator_start_value(meter, indic, 0); //刻度线起始值0
    lv_meter_set_indicator_end_value(meter, indic, 20);//刻度线结束值20
    /*Add a red arc to the end*/
    indic = lv_meter_add_arc(meter, scale, 3, lv_palette_main(LV_PALETTE_RED), 0);//添加红色表弧指示
    lv_meter_set_indicator_start_value(meter, indic, 80); // 起始指示值80
    lv_meter_set_indicator_end_value(meter, indic, 100); // 结束指示值100
    /*Make the tick lines red at the end of the scale*/
    indic = lv_meter_add_scale_lines(meter, scale, lv_palette_main(LV_PALETTE_RED), lv_palette_main(LV_PALETTE_RED), false,
        0);// 添加红色刻度线
    lv_meter_set_indicator_start_value(meter, indic, 80); //刻度线起始值80
    lv_meter_set_indicator_end_value(meter, indic, 100);//刻度线结束值100
    /*Add a needle line indicator*/
    indic = lv_meter_add_needle_line(meter, scale, 4, lv_palette_main(LV_PALETTE_GREY), -10); // 添加灰色表针
    /*Create an animation to set the value*/
    lv_anim_t a;
    lv_anim_init(&a);  
    lv_anim_set_exec_cb(&a, set_value); //关联动画执行函数
    lv_anim_set_var(&a, indic); // 设置关联变量到动画
    lv_anim_set_values(&a, 0, 100);  // 设置动画起始值0，结束值100
    lv_anim_set_time(&a, 2000);  // 调置动画duration时间
    lv_anim_set_repeat_delay(&a, 100); // 设置重复动画前的延时时间
    lv_anim_set_playback_time(&a, 500); // 设置动画回播时间
    lv_anim_set_playback_delay(&a, 100); // 设置开始回播前的延时时间
    lv_anim_set_repeat_count(&a, LV_ANIM_REPEAT_INFINITE); // 无限循环重复播放 
    lv_anim_start(&a);  //启动动画
}

运行效果