ListView控件显示日志每次刷新只显示30条数据

 

 

功能: 实时记录接收数据,用listview控件显示出来,保持数据一直是30条

 

1.将信息显示到控件。

/// <summary>
    /// 在ListView控件里显示日志信息
    /// </summary>
    public class CustomListViewDisplayNews
    {
        /// <summary>
        /// 委托控件显示数据
        /// </summary>
        /// <param name="list">控件</param>
        /// <param name="index">序号</param>
        /// <param name="code">第一个值</param>
        /// <param name="data">第二个值</param>
        /// <param name="time">时间</param>
        public delegate void DisplayNews(ListView list, double index,string code, string data,string time);

        /// <summary>
        /// 显示的信息数
        /// </summary>
        public static int Num_Record = 0;
        
        private void ListView_DisplayNews(ListView list, double iIndex,string Code,string Data,string Time)
        {
            if (list.InvokeRequired == false)
            {
                ListViewItem lvi = new ListViewItem();
                lvi.SubItems[0].Text = iIndex.ToString();
                lvi.SubItems.Add(Code);
                lvi.SubItems.Add(Data);
                lvi.SubItems.Add(Time);
                list.Items.Insert(0, lvi);
                for (int i = 0; i < list.Columns.Count; i++)
                {
                    list.Columns[i].Width = -2;
                }
            }
            else
            {
                //通过使用Invoke的方法,让子线程告诉窗体线程来完成相应的控件操作
                DisplayNews degete = new DisplayNews(ListView_DisplayNews);
                //使用控件lstMain的Invoke方法执行DMSGD代理(其类型是DispMSGDelegate)
                list.Invoke(degete, (object)iIndex, (object)Code, (object)Data, (object)Time);
            }

        }
        /// <summary>
        /// 调函数显示list信息
        /// </summary>
        /// <param name="list">容器</param>
        /// <param name="result">值</param>
        /// <param name="value">值</param>
        public void listView_DisplayNews(ListView list, object value,object result)
        {
            DisplayNews dis = new DisplayNews(ListView_DisplayNews);
            string Read_Value = (string)value;
            string Read_Result = (string)result;
            Num_Record++;
            ListView_DisplayNews(list, Num_Record, Read_Value,Read_Result, DateTime.Now.ToString());
        }
    }

 1.1调用函数显示日志

 

CustomListViewDisplayNews list = new CustomListViewDisplayNews();
list.listView_DisplayNews(listView1, "NG", "NoRead");

  

2.保持数据显示一直是30条。

   思路:控件显示数据可分为头数据和尾数据,如第1条显示数据为头数据,第30是尾数据。当增加到31条数据时,把头数据删掉,序号不变。

当控件大于30条数据时,每刷新一条都执行一遍删除头数据的代码

if (CustomListViewDisplayNews.Num_Record > 30)
{
     RefreshListview();
}

 

private void RefreshListview()
{
      int nRowOrder = 0;
      int nRowOrders = listView1.Items.Count;//行数
      for (nRowOrder = 0; nRowOrder < nRowOrders; nRowOrder++)
      {
          var row = nRowOrders - 1;

          if (nRowOrder == row)
          {
              listView1.Items.RemoveAt(row);
          }
      }
}

  更简易的代码可以这样写

if (CustomListViewDisplayNews.Num_Record > 30)
{
     listView1.Items.RemoveAt(30);
}

  

  

 

 

posted @ 2020-10-16 10:11  漫漫步子  阅读(297)  评论(2编辑  收藏  举报