CascadingDropDown控件

发布时间：2020-12-17 02:46:34 所属栏目：安全来源：网络整理

导读：添加一个 WebService.asmx ? 添加标签 :[System.Web.Script] ? Get { ??? Lock(objectLock)// 在 lock 里是一个临界区 , 在这个临界区只能有一个线程 , 要有其它线程调用必须等这个线程释放才可以 . 由 private static XmlDocument xmlDoc; 进行线程程操作 {

添加一个WebService.asmx

?添加标签:[System.Web.Script]

Get

{

??? Lock(objectLock)//在lock里是一个临界区,在这个临界区只能有一个线程,要有其它线程调用必须等这个线程释放才可以.由private static XmlDocument xmlDoc;进行线程程操作

{

?????? xmlDoc.Load(HttpContext.Current.Server.MapPath(“~/App_Data/XML.xml”)// 加载文件

}

return xmlDoc;

}

public static string[] Hierarch//用于返回交节点和子节点//

{

?????? get{return? new string[] {“province”,”city”};}

}

public AjaxControlToolkit.CascadingDropDownNameValue[] GetDropDownContents(string knowCategoryValues,string category)

//province name=”江苏,values值就是江苏,category 就是province

{//StringDictionary需要using System.Collections.Specialized

??? StringDictionary knownCataegoryValuesDictionary = AjaxControlToolkit.CascadingDropDown.ParaseKnowCategoryValuesString(knowCategoryValues);//将value值转换成StringDictionary类的一个

}

三个DropDownList

中的CascadingDropDown1,2,3(CascadingDropDown)

Category:对应着的1,3分别填province,city,county

LoadingText:正在加载

ParentControlID:第一个CascadingDropDown1不用写,这里实现一个连动效果,当选择省的时候,第二个就会出现相应的市,第三个出现县

??? 所以第二个与第三个分别选择DropDownList1,DropDownList2

PromptText分别真请选择省,请选择市,请选择县

ServiceMethod:都填写GetDropDownContents

ServicePath:都填写 WebService.asmx

更UpdatePanel属性的Triggers(Collection)添加,更改ControlID为DropDownList3,EventName为SelectedIndexChange这个是触发事件

UpdatePanel1的RenderMode更改为Inline是内嵌式的,UpdateMode选择Conditional

编写DropDownList3_SelectedIndexChanged(object sender,EventArgs e)

在Deault.aspx中的第一个<>中加入EnableEventValidation=”false”否则Lable1会出错,而且还要修改第三DropDownList选择它的小三角AutoPostPack画勾

代码如下 :

Default.aspx.cs

using System;

using System.Data;

using System.Configuration;

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;

public partial class _Default : System.Web.UI.Page

{

??? protected void Page_Load(object sender,EventArgs e)

??? {

??? }

??? protected void DropDownList3_SelectedIndexChanged(object sender,EventArgs e)

??? {

??????? if (DropDownList3.SelectedItem.Text == "")

??????? {

??????????? this.Label1.Text = "您还有一项没有选择哦!";

??????? }

??????? else

????? ??{

?????????? Label1.Text = "您的籍贯是" + DropDownList1.SelectedItem.Text+ DropDownList2.SelectedItem.Text + DropDownList3.SelectedItem.Text;

??????? }

??? }

}

WebService.cs

using System;

using System.Web;

using System.Collections.Specialized;

using System.Web.Services;

using System.Web.Services.Protocols;

using System.Xml;

/// <summary>

/// WebService 的摘要说明

/// </summary>

[WebService(Namespace = "http://tempuri.org/")]

[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]

[System.Web.Script.Services.ScriptService]//添加标签,从客户端调用服务端WebService方法时

public class WebService : System.Web.Services.WebService

{

??? public WebService()

??? {

??????? //如果使用设计的组件，请取消注释以下行

??????? //InitializeComponent();

??? }

??? private static XmlDocument xmlDoc;

??? private static object objectLock = new object();

??? public static XmlDocument Document

??? {

??????? get

??????? {

??????????? lock (objectLock)//在lock里是一个临界区,要有其它线程调用必须等这个线程释放才可以.由private static XmlDocument xmlDoc;进行线程程操作

??????????? {

??????? ????????if (xmlDoc == null)

??????????????? {

??????????????????? xmlDoc = new XmlDocument();

??????????????????? xmlDoc.Load(HttpContext.Current.Server.MapPath("~/App_Data/XML.xml"));// 加载文件

??????????????? }

??????????? }

??????????? return xmlDoc;

???? ???}

??? }

??? public static string[] Hierarchy

??? {

??????? get { return new string[] { "province","city" }; } //用于返回交节点和子节点

??? }

??? [WebMethod]

??? public AjaxControlToolkit.CascadingDropDownNameValue[] GetDropDownContents(string knownCategoryValues,string category)

??? //province name=江苏,category就是province

??? {

??????? //StringDictionary需要using System.Collections.Speciallized

??????? StringDictionary knownCategoryValuesDictionary = AjaxControlToolkit.CascadingDropDown.ParseKnownCategoryValuesString(knownCategoryValues);//将value值转换成StringDictionary类的一个

??????? return AjaxControlToolkit.CascadingDropDown.QuerySimpleCascadingDropDownDocument(Document,Hierarchy,knownCategoryValuesDictionary,category);//返回XML上的信息显示到界面上来

??? }

}

XML.xml

<?xml version="1.0" encoding="utf-8"?>

?

? <province name="江苏"><!—也可以通过单击右键查看数据风格打开一个表进行数据添加 -->

??? <city name="盐城市">

????? <country name="建湖县" />

????? <country name="盐城县" />

??? </city>

??? <city name="南通市">

????? <country name="海安县" />

????? <country name="如东县" />

??? </city>

??? <city name="扬州市">

????? <country name="宝应县" />

??? </city>

? </province>

? <province name="广东省">

??? <city name="潮州市">

????? <country name="潮安县">

????? </country>

??? </city>

??? <city name="河源市">

????? <country name="东源县">

????? </country>

??? </city>

? </province>

</WebServer>

Default.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" EnableEventValidation="False"? %>

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">

??? <title>Untitled Page</title>

</head>

??? <form id="form1" runat="server">

??????? <asp:ScriptManager ID="ScriptManager1" runat="server" />

??????? <table border="1">

??????????? <tr>