标题: ASP.NET用户控件：增强型CheckBoxList控件
作者: dnawo
日期: 2008-09-14 03:08 PM
分类: Web编程
内容: .NET的CheckBoxList控件允许进行多项选择，但是其SelectedValue属性值却只能取到第一个选择项的值，如果要获取全部选择项的值必须遍历各项判断选中再获取，同样你也无法一次设置多个项为选中状态，比较麻烦。下边我们重新创建一个CheckBoxList控件，他继承于CheckBoxList类，增加了两个属性NewSelectedText和NewSelectedValue，可一次性设置或获取CheckBoxList实例全部选择项的Text和Value值。
自定义CheckBoxList控件源码
打开Microsoft Visual Studio 2005，在类库中添加新项，选择"Web 自定义控件"，名称为CheckBoxList.cs：
复制内容到剪贴板 程序代码using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace MzwuCom.UI
{
/// <summary>
/// 多项选择复选框组
/// </summary>
[DefaultProperty("Text")]
[ToolboxData("<{0}:CheckBoxList runat=server></{0}:CheckBoxList>")]
public class CheckBoxList : System.Web.UI.WebControls.CheckBoxList
{
private const char SEPARATOR = '|';//分隔符
/// <summary>
/// 选中项的Text值
/// </summary>
[Browsable(false)]
[DefaultValue("")]
public string NewSelectedText
{
set
{
if (value != null && value != string.Empty && value != "")
{
//取消原先选择项
//for (int i = 0; i < this.Items.Count; i++)
//{
// this.Items[i].Selected = false;
//}
this.SelectedIndex = -1;
//重新选择
string[] textList = value.Split(new char[] { SEPARATOR });
for (int i = 0; i < textList.Length; i++)
{
for (int j = 0; j < this.Items.Count; j++)
{
if (this.Items[j].Text == textList[i])
{
this.Items[j].Selected = true;
}
}
}
}
}
get
{
string textList = string.Empty;
for (int i = 0; i < this.Items.Count; i++)
{
if (this.Items[i].Selected == true)
{
textList += this.Items[i].Text + SEPARATOR.ToString();
}
}
if (textList != string.Empty)
{
return textList.Substring(0, textList.Length - 1);
}
else
{
return textList;
}
}
}
/// <summary>
/// 属性:选中项的Value值
/// </summary>
[Browsable(false)]
[DefaultValue("")]
public string NewSelectedValue
{
set
{
if (value != null && value != string.Empty && value != "")
{
//取消原先选择项
//for (int i = 0; i < this.Items.Count; i++)
//{
// this.Items[i].Selected = false;
//}
this.SelectedIndex = -1;
//重新选择
string[] valueList = value.Split(new char[] { SEPARATOR });
for (int i = 0; i < valueList.Length; i++)
{
for (int j = 0; j < this.Items.Count; j++)
{
if (this.Items[j].Value == valueList[i])
{
this.Items[j].Selected = true;
}
}
}
}
}
get
{
string valueList = string.Empty;
for (int i = 0; i < this.Items.Count; i++)
{
if (this.Items[i].Selected == true)
{
valueList += this.Items[i].Value + SEPARATOR.ToString();
}
}
if (valueList != string.Empty)
{
return valueList.Substring(0, valueList.Length - 1);
}
else
{
return valueList;
}
}
}
}
}
生成后在工具箱就能看到他了：
使用示例
Test.aspx:
复制内容到剪贴板 程序代码<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Test.aspx.cs" Inherits="Test" %>
<%@ Register Assembly="MzwuCom.UI" Namespace="MzwuCom.UI" TagPrefix="cc1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>.NET自定义控件：增强型CheckBoxList控件-Mzwu.Com</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<cc1:checkboxlist id="CheckBoxList1" runat="server" repeatcolumns="4" RepeatDirection="Horizontal"><asp:ListItem Value="1">选项1</asp:ListItem>
<asp:ListItem Value="2">选项2</asp:ListItem>
<asp:ListItem Value="3">选项3</asp:ListItem>
<asp:ListItem Value="4">选项4</asp:ListItem>
<asp:ListItem Value="5">选项5</asp:ListItem>
<asp:ListItem Value="6">选项6</asp:ListItem>
<asp:ListItem Value="7">选项7</asp:ListItem>
<asp:ListItem Value="8">选项8</asp:ListItem>
</cc1:checkboxlist>
<asp:Button ID="Button1" runat="server" Text="Set NewSelectedText" OnClick="Button1_Click" />
<br />
<asp:Button ID="Button2" runat="server" Text="Get NewSelectedText" OnClick="Button2_Click" />
<br />
<asp:Button ID="Button3" runat="server" Text="Set NewSelectedValue" OnClick="Button3_Click" />
<br />
<asp:Button ID="Button4" runat="server" Text="Get NewSelectedValue" OnClick="Button4_Click" /><br />
<br />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</div>
</form>
</body>
</html>
Test.aspx.cs:
复制内容到剪贴板 程序代码using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using MzwuCom.UI;
public partial class Test : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
//
}
/// <summary>
/// Set NewSelectedText
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Button1_Click(object sender, EventArgs e)
{
CheckBoxList1.NewSelectedText = "选项1|选项3|选项5|选项7";
Label1.Text = "Set NewSelectedText: " + CheckBoxList1.NewSelectedText;
}
/// <summary>
/// Get NewSelectedText
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Button2_Click(object sender, EventArgs e)
{
Label1.Text = "Get NewSelectedText: " + CheckBoxList1.NewSelectedText;
}
/// <summary>
/// Set NewSelectedValue
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Button3_Click(object sender, EventArgs e)
{
CheckBoxList1.NewSelectedValue = "2|4|6|8";
Label1.Text = "Set NewSelectedValue: " + CheckBoxList1.NewSelectedValue;
}
/// <summary>
/// Get NewSelectedValue
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Button4_Click(object sender, EventArgs e)
{
Label1.Text = "Get NewSelectedValue: " + CheckBoxList1.NewSelectedValue;
}
}
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