学步园

List<tb_History> histories;

histories = new List<tb_History>();

var temps = HistoryManager.getHistoriesByPrifileId(selected_Profile.id);

foreach (var temp in temps)
            {
                histories.Add(temp);
            }

if (histories.Count <= 0)
            {
                ClearAllLabels();
                return;
            }

// 首先 按照 Sys排序
            histories.Sort(new ComparableHistorySys());

            int sys_min = histories[0].systolic;
            int sys_max = histories[histories.Count - 1].systolic;

// 排序方法，默认从小到大排序
    public class ComparableHistorySys : IComparer<tb_History>
    {
        public int Compare(tb_History x, tb_History y)
        {
            return x.systolic.CompareTo(y.systolic);
        }
    }