• winform listview 虚拟模式


    1、加载数据、排序、删除、更新、获取选中的值

    重新加载llistview时,如果listviewitem的count变化了,必须重新设置 listView1.VirtualListSize,然后   listView1.Invalidate()刷新。

      1 using System;
      2 using System.Collections.Generic;
      3 using System.Text;
      4 using System.Windows.Forms;
      5 
      6 namespace WindowsFormsApp32
      7 {
      8     public partial class Form6 : Form
      9     {
     10         private List<ListViewItem> m_hListViewItems = null;//设置缓存容器
     11         private MMySorter mySort = null;//排序方式
     12         public Form6()
     13         {
     14             InitializeComponent();
     15             m_hListViewItems = new List<ListViewItem>();
     16             mySort = new MMySorter();
     17             #region listview的数据和样式
     18             ColumnHeader c1 = new ColumnHeader() { Text = "id" };
     19             ColumnHeader c2 = new ColumnHeader() { Text = "name" };
     20             ColumnHeader c3 = new ColumnHeader() { Text = "bir", Width = 200 };
     21             listView1.Columns.AddRange(new ColumnHeader[] { c1, c2, c3 });
     22             for (int i = 0; i < 20000; i++)
     23             {
     24                 ListViewItem li = new ListViewItem() { Text = i.ToString() };
     25                 li.SubItems.Add("name" + i);
     26                 li.SubItems.Add(DateTime.Now.AddDays(i * 1.00).ToString("yyyy-MM-dd hh:mm:ss"));
     27                 m_hListViewItems.Add(li);
     28             }
     29             listView1.GridLines = true;
     30             listView1.FullRowSelect = true;
     31             listView1.Cursor = Cursors.Hand;
     32             #endregion
     33             #region listview设置虚拟模式
     34             listView1.VirtualMode = true;
     35             listView1.VirtualListSize = m_hListViewItems.Count;
     36             listView1.RetrieveVirtualItem += ListView1_RetrieveVirtualItem;
     37             #endregion
     38             listView1.ColumnClick += ListView1_ColumnClick;
     39             listView1.SelectedIndexChanged += ListView1_SelectedIndexChanged;
     40             listView1.VirtualItemsSelectionRangeChanged += ListView1_VirtualItemsSelectionRangeChanged;
     41         }
     42 
     43         private void ListView1_VirtualItemsSelectionRangeChanged(object sender, ListViewVirtualItemsSelectionRangeChangedEventArgs e)
     44         {
     45             if (e.IsSelected)//连续选中的数量
     46                 this.Text = (e.EndIndex -e.StartIndex+1).ToString();
     47         }
     48         private void ListView1_SelectedIndexChanged(object sender, EventArgs e)
     49         {
     50             this.Text = listView1.SelectedIndices.Count.ToString();
     51         }
     52         private void ListView1_ColumnClick(object sender, ColumnClickEventArgs e)
     53         {
     54             if (e.Column == mySort.columnToSort)
     55             {
     56                 mySort.so = mySort.so == SortOrder.Ascending ? SortOrder.Descending : SortOrder.Ascending;
     57             }
     58             else
     59             {
     60                 mySort.so = SortOrder.Ascending;
     61                 mySort.columnToSort = e.Column;
     62             }
     63             m_hListViewItems.Sort(mySort);//指定排序方法
     64             listView1.Invalidate();
     65         }
     66 
     67         private void ListView1_RetrieveVirtualItem(object sender, RetrieveVirtualItemEventArgs e)
     68         {
     69             if (m_hListViewItems == null || m_hListViewItems.Count == 0)
     70                 return;
     71             e.Item = m_hListViewItems[e.ItemIndex];
     72             if (e.ItemIndex == m_hListViewItems.Count)
     73                 m_hListViewItems = null;
     74         }
     75         private void button1_Click(object sender, EventArgs e)
     76         {
     77             #region 添加数据
     78             List<ListViewItem> ll = new List<ListViewItem>();
     79             for (int i = 20000; i < 30000; i++)
     80             {
     81                 ListViewItem li = new ListViewItem() { Text = i.ToString() };
     82                 li.SubItems.Add("name" + i);
     83                 li.SubItems.Add(DateTime.Now.AddDays(i * 1.00).ToString("yyyy-MM-dd hh:mm:ss"));
     84                 ll.Add(li);
     85             }
     86             m_hListViewItems.AddRange(ll);
     87             listView1.VirtualListSize = m_hListViewItems.Count;
     88             #endregion
     89 
     90         }
     91         private void button2_Click(object sender, EventArgs e)
     92         {
     93             #region 更新数据
     94             for (int i = 0; i < m_hListViewItems.Count; i++)
     95             {
     96                 m_hListViewItems[i].SubItems[1].Text = m_hListViewItems[i].SubItems[1].Text + DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss");
     97             }
     98             listView1.Invalidate();
     99             #endregion
    100         }
    101         private void button3_Click(object sender, EventArgs e)
    102         {
    103             #region 删除数据
    104             int deleStart = 0;
    105             int deleEnd = 100;
    106             m_hListViewItems.RemoveRange(deleStart, deleEnd - deleStart);
    107             listView1.VirtualListSize = m_hListViewItems.Count;
    108             listView1.Invalidate();
    109             #endregion
    110         }
    111 
    112         private void button4_Click(object sender, EventArgs e)
    113         {
    114             #region 获得所选行的数据值
    115             StringBuilder sb = new StringBuilder();
    116             foreach (int i in listView1.SelectedIndices)
    117             {
    118                 sb.AppendLine(listView1.Items[i].SubItems[0].Text);
    119             }
    120             MessageBox.Show(sb.ToString());
    121             #endregion
    122         }
    123     }
    124 }
    View Code
       class MMySorter : IComparer<ListViewItem>//此处必须是IComparer<ListViewItem>接口,不能是IComparer接口,否则报错。
        {
            public int columnToSort { get; set; }
            public SortOrder so { get; set; }
            private CaseInsensitiveComparer cic;
            public MMySorter()
            {
                columnToSort = 0;
                so = SortOrder.None;
                cic = new CaseInsensitiveComparer();
            }
            int IComparer<ListViewItem>.Compare(ListViewItem x, ListViewItem y)
            {
                int result = 0;
                ListViewItem lx = x;
                ListViewItem ly = y;
                string xtext = lx.SubItems[columnToSort].Text;
                string ytext = ly.SubItems[columnToSort].Text;
                int xx = 0, yy = 0;
                if (int.TryParse(xtext, out xx) && int.TryParse(ytext, out yy))
                    result = xx.CompareTo(yy);
                else
                    result = xtext.CompareTo(ytext);
                if (so == SortOrder.Ascending)
                    return result;
                else if (so == SortOrder.Descending)
                    return -result;
                else
                    return result;
            }
        }
    View Code

    2.checkBox

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  • 原文地址:https://www.cnblogs.com/wwz-wwz/p/7359679.html
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