LVGL V8.2.0之Axis ticks and labels with scrolling

绘制函数回调

static void draw_event_cb(lv_event_t* e)
{
    lv_obj_draw_part_dsc_t* dsc = lv_event_get_draw_part_dsc(e); //获取事件对象绘制描述符指针
    if (!lv_obj_draw_part_check_type(dsc, &lv_chart_class, LV_CHART_DRAW_PART_TICK_LABEL)) return; // LV_CHART_DRAW_PART_TICK_LABEL部分不绘制
    if (dsc->id == LV_CHART_AXIS_PRIMARY_X && dsc->text) {
        const char* month[] = { "Jan", "Febr", "March", "Apr", "May", "Jun", "July","Aug", "Sept", "Oct", "Nov", "Dec" };
        lv_snprintf(dsc->text, dsc->text_length, "%s", month[dsc->value]); //格式化显示内容到dsc->text指向的内存
    }
}

创建CHART

static void lv_example_chart_3(void)
{
    /*Create a chart*/
    lv_obj_t* chart;
    chart = lv_chart_create(lv_scr_act()); //创建CHART对象
    lv_obj_set_size(chart, 200, 150); // 设置大小
    lv_obj_center(chart);  //居中显示
    lv_chart_set_type(chart, LV_CHART_TYPE_BAR); //设置CHART为BAR类型
    lv_chart_set_range(chart, LV_CHART_AXIS_PRIMARY_Y, 0, 100); //设置y主轴范围为0~100
    lv_chart_set_range(chart, LV_CHART_AXIS_SECONDARY_Y, 0, 400);//设置y第2轴范围为0~400
    lv_chart_set_point_count(chart, 12);  // 设置12个BAR形点数
    lv_obj_add_event_cb(chart, draw_event_cb, LV_EVENT_DRAW_PART_BEGIN, NULL);//添加LV_EVENT_DRAW_PART_BEGIN绘制事件
    /*Add ticks and label to every axis*/
    lv_chart_set_axis_tick(chart, LV_CHART_AXIS_PRIMARY_X, 10, 5, 12, 3, true, 40);
    lv_chart_set_axis_tick(chart, LV_CHART_AXIS_PRIMARY_Y, 10, 5, 6, 2, true, 50);
    lv_chart_set_axis_tick(chart, LV_CHART_AXIS_SECONDARY_Y, 10, 5, 3, 4, true, 50);
    /*Zoom in a little in X*/
    lv_chart_set_zoom_x(chart, 800);  // x方向放大800/256倍
    /*添加2条数据线*/
    lv_chart_series_t* ser1 = lv_chart_add_series(chart, lv_palette_lighten(LV_PALETTE_GREEN, 2), LV_CHART_AXIS_PRIMARY_Y); 
    lv_chart_series_t* ser2 = lv_chart_add_series(chart, lv_palette_darken(LV_PALETTE_GREEN, 2),
        LV_CHART_AXIS_SECONDARY_Y);
    /*设置数据到ser1'*/
    lv_chart_set_next_value(chart, ser1, 31);
    lv_chart_set_next_value(chart, ser1, 66);
    lv_chart_set_next_value(chart, ser1, 10);
    lv_chart_set_next_value(chart, ser1, 89);
    lv_chart_set_next_value(chart, ser1, 63);
    lv_chart_set_next_value(chart, ser1, 56);
    lv_chart_set_next_value(chart, ser1, 32);
    lv_chart_set_next_value(chart, ser1, 35);
    lv_chart_set_next_value(chart, ser1, 57);
    lv_chart_set_next_value(chart, ser1, 85);
    lv_chart_set_next_value(chart, ser1, 22);
    lv_chart_set_next_value(chart, ser1, 58);
    lv_coord_t* ser2_array = lv_chart_get_y_array(chart, ser2);
    /*设置数据到ser2'*/
    ser2_array[0] = 92;
    ser2_array[1] = 71;
    ser2_array[2] = 61;
    ser2_array[3] = 15;
    ser2_array[4] = 21;
    ser2_array[5] = 35;
    ser2_array[6] = 35;
    ser2_array[7] = 58;
    ser2_array[8] = 31;
    ser2_array[9] = 53;
    ser2_array[10] = 33;
    ser2_array[11] = 73;
    lv_chart_refresh(chart); /*刷新显示*/
}

运行效果图