ListView控件演示03：如何在列表添加项的时候减少UI的刷新

代码示例演示如何初始化ListView控件以包含复选框。它还阐释了如何使用BeginUpdate和EndUpdate方法。
通过对BeginUpdate和EndUpdate方法的使用，可以减少在为列表添加项时UI的重绘次数。如果不使用这2个方法，则每向ListView添加一个列表项时，都会重绘ListView控件。



程序截图





程序代码

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

namespace Demo03
{
    public partial class MainForm : Form
    {
        ListView listView;

        public MainForm()
        {
            InitializeComponent();

            this.InitializeListView();
        }

        private void InitializeListView()
        {
            this.listView = new System.Windows.Forms.ListView();

            // Set properties such as BackColor and DockStyle and Location.
            this.listView.BackColor = System.Drawing.SystemColors.Control;
            this.listView.Dock = System.Windows.Forms.DockStyle.Top;
            this.listView.Location = new System.Drawing.Point(0, 0);
            this.listView.Size = new System.Drawing.Size(292, 130);
            this.listView.View = System.Windows.Forms.View.Details;
            this.listView.HideSelection = false;

            // Allow the user to select multiple items.
            this.listView.MultiSelect = true;

            // Show CheckBoxes in the ListView.
            this.listView.CheckBoxes = true;

            //Set the column headers and populate the columns.
            listView.HeaderStyle = ColumnHeaderStyle.Nonclickable;

            ColumnHeader columnHeader1 = new ColumnHeader();
            columnHeader1.Text = "Breakfast Choices";
            columnHeader1.TextAlign = HorizontalAlignment.Left;
            columnHeader1.Width = 146;

            ColumnHeader columnHeader2 = new ColumnHeader();
            columnHeader2.Text = "Price Each";
            columnHeader2.TextAlign = HorizontalAlignment.Center;
            columnHeader2.Width = 142;

            this.listView.Columns.Add(columnHeader1);
            this.listView.Columns.Add(columnHeader2);

            string[] foodList = new string[]{"Juice", "Coffee", 
			"Cereal & Milk", "Fruit Plate", "Toast & Jelly", 
			"Bagel & Cream Cheese"};

            string[] foodPrice = new string[]{"1.09", "1.09", "2.19", 
			"2.79", "2.09", "2.69"};

            int count;

            // Members are added one at a time, so call BeginUpdate to ensure 
            // the list is painted only once, rather than as each list item is added.

            // 一旦调用了BeginUpdate()这个方法，要直到调用EndUpdate()方法时才会重新绘制ListView。
            // 因此下面连续添加了几个ListViewItem都不会重新绘制ListView。
            listView.BeginUpdate();

            for (count = 0; count < foodList.Length; count++)
            {
                ListViewItem listItem = new ListViewItem(foodList[count]);
                listItem.SubItems.Add(foodPrice[count]);
                listView.Items.Add(listItem);
            }

            //Call EndUpdate when you finish adding items to the ListView.
            // 调用这个方法就会重新绘制ListView了，这是会把前面添加的所有ListViewItem绘制到控件上。
            listView.EndUpdate();

            this.Controls.Add(this.listView);
        }

    }
}