ListView VirtualMode Demo

向ListView中添加大量数据的时候,往往都慢的令人难受,使用VirtualMode模式可大大改善呈现的性能.以下Demo了一下ListView使用时候的常见场景,包括加载/更新/删除/排序

namespace ListviewVirtualTest
{
    partial class Form2
    {
        /**//// <summary>
        /// 必需的设计器变量。
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /**//// <summary>
        /// 清理所有正在使用的资源。
        /// </summary>
        /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        Windows 窗体设计器生成的代码#region Windows 窗体设计器生成的代码

        /**//// <summary>
        /// 设计器支持所需的方法 - 不要
        /// 使用代码编辑器修改此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {
            this.button1 = new System.Windows.Forms.Button();
            this.listView1 = new System.Windows.Forms.ListView();
            this.columnHeader1 = new System.Windows.Forms.ColumnHeader();
            this.columnHeader2 = new System.Windows.Forms.ColumnHeader();
            this.button2 = new System.Windows.Forms.Button();
            this.button3 = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(1, 2);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(75, 23);
            this.button1.TabIndex = 0;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // listView1
            // 
            this.listView1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
                        | System.Windows.Forms.AnchorStyles.Left)
                        | System.Windows.Forms.AnchorStyles.Right)));
            this.listView1.Columns.AddRange(new System.Windows.Forms.ColumnHeader[] {
            this.columnHeader1,
            this.columnHeader2});
            this.listView1.Location = new System.Drawing.Point(1, 31);
            this.listView1.Name = "listView1";
            this.listView1.Size = new System.Drawing.Size(592, 388);
            this.listView1.TabIndex = 1;
            this.listView1.UseCompatibleStateImageBehavior = false;
            this.listView1.View = System.Windows.Forms.View.Details;
            this.listView1.ColumnClick += new System.Windows.Forms.ColumnClickEventHandler(this.listView1_ColumnClick);
            // 
            // columnHeader1
            // 
            this.columnHeader1.Width = 138;
            // 
            // columnHeader2
            // 
            this.columnHeader2.Width = 214;
            // 
            // button2
            // 
            this.button2.Location = new System.Drawing.Point(82, 2);
            this.button2.Name = "button2";
            this.button2.Size = new System.Drawing.Size(75, 23);
            this.button2.TabIndex = 2;
            this.button2.Text = "button2";
            this.button2.UseVisualStyleBackColor = true;
            this.button2.Click += new System.EventHandler(this.button2_Click);
            // 
            // button3
            // 
            this.button3.Location = new System.Drawing.Point(163, 2);
            this.button3.Name = "button3";
            this.button3.Size = new System.Drawing.Size(75, 23);
            this.button3.TabIndex = 3;
            this.button3.Text = "button3";
            this.button3.UseVisualStyleBackColor = true;
            this.button3.Click += new System.EventHandler(this.button3_Click);
            // 
            // Form2
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(595, 431);
            this.Controls.Add(this.button3);
            this.Controls.Add(this.button2);
            this.Controls.Add(this.listView1);
            this.Controls.Add(this.button1);
            this.Name = "Form2";
            this.Text = "Form2";
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.ListView listView1;
        private System.Windows.Forms.ColumnHeader columnHeader1;
        private System.Windows.Forms.ColumnHeader columnHeader2;
        private System.Windows.Forms.Button button2;
        private System.Windows.Forms.Button button3;
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace ListviewVirtualTest
{
    public partial class Form2 : Form
    {
        private List<ListViewItem> m_hListViewItems;
        private MySorter mySorter;
        public Form2()
        {
            InitializeComponent();
            m_hListViewItems = new List<ListViewItem>();
            mySorter = new MySorter();
        }

        void listView_RetrieveVirtualItem(object sender, RetrieveVirtualItemEventArgs e)
        {
            e.Item = m_hListViewItems[e.ItemIndex];
        }

        private void button1_Click(object sender, EventArgs e)
        {
            int NR = 10000;

            for (int i = 0; i < NR; i++)
                m_hListViewItems.Add(
                    new ListViewItem(new string[] { i + " test1", i + " test2" }));

            listView1.RetrieveVirtualItem += new RetrieveVirtualItemEventHandler(listView_RetrieveVirtualItem);

            listView1.VirtualListSize = NR;
            listView1.VirtualMode = true;
        }

        //更新
        private void button2_Click(object sender, EventArgs e)
        {
            for (int i = 0; i < m_hListViewItems.Count; i++)
            {
                m_hListViewItems[i].SubItems[0].Text = i + " " + DateTime.Now.ToString();
                m_hListViewItems[i].SubItems[1].Text = i + " " + DateTime.Now.ToString();
            }

            listView1.Invalidate();
        }

        // 删除
        private void button3_Click(object sender, EventArgs e)
        {
            List<ListViewItem> list = new List<ListViewItem>();
            for (int i = 0; i < m_hListViewItems.Count; i += 2)
            {
                list.Add(m_hListViewItems[i]);
            }
            foreach (ListViewItem lvi in list)
            {
                m_hListViewItems.Remove(lvi);
            }

            listView1.VirtualListSize = m_hListViewItems.Count;
            listView1.Invalidate();
        }


        //排序
        private void listView1_ColumnClick(object sender, ColumnClickEventArgs e)
        {
            if (e.Column == mySorter.ColumnIndex)
            {
                mySorter.SortOrder = (
                    mySorter.SortOrder == SortOrder.Descending ?
                    SortOrder.Ascending : SortOrder.Descending);
            }
            else
            {
                mySorter.SortOrder = SortOrder.Ascending;
                mySorter.ColumnIndex = e.Column;
            }

            m_hListViewItems.Sort(mySorter);

            listView1.Invalidate();
        }

    }
}

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;

namespace ListviewVirtualTest
{
    public class MySorter : System.Collections.Generic.IComparer<ListViewItem>
    {
        public SortOrder SortOrder = SortOrder.None;
        public int ColumnIndex = -1;

        

        IComparer  成员#region IComparer<ListViewItem> 成员

        public int Compare(ListViewItem x, ListViewItem y)
        {
            ListViewItem hLeft = x;
            ListViewItem hRiht = y;

            if (SortOrder == SortOrder.Ascending && (ColumnIndex >= 0) && (ColumnIndex < hLeft.SubItems.Count))
            {
                string sx = hLeft.SubItems[ColumnIndex].Text;
                string sy = hRiht.SubItems[ColumnIndex].Text;
                return sx.CompareTo(sy);
            }
            if (SortOrder == SortOrder.Descending && (ColumnIndex >= 0) && (ColumnIndex < hLeft.SubItems.Count))
            {
                string sx = hLeft.SubItems[ColumnIndex].Text;
                string sy = hRiht.SubItems[ColumnIndex].Text;
                return sy.CompareTo(sx);
            }
            return 0;
        }

        #endregion
    }
}

using System;
using System.Collections.Generic;
using System.Windows.Forms;

namespace ListviewVirtualTest
{
    static class Program
    {
        /**//// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form2());
        }
    }
}