CascadingDropDown控件

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CascadingDropDown控件

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1,2,3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,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

{

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,values值就是江苏,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"?>

</city>

</city>

</city>

</province>

</country>

</city>

</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>

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

<tr>

省</td>

<asp:DropDownList ID="DropDownList1" runat="server" Width="100px">

</asp:DropDownList></td>

</tr>

<tr>

市</td>

<asp:DropDownList ID="DropDownList2" runat="server" Width="100px">

</asp:DropDownList></td>

</tr>

<tr>

县</td>

<asp:DropDownList ID="DropDownList3" runat="server" Width="100px" OnSelectedIndexChanged="DropDownList3_SelectedIndexChanged" AutoPostBack="True">

</asp:DropDownList></td>

</tr>

</table>

<div>

<cc1:CascadingDropDown ID="CascadingDropDown1" runat="server" TargetControlID="DropDownList1" Category="province" LoadingText="正在加载...." PromptText="请选择省份" ServiceMethod="GetDropDownContents" ServicePath="WebService.asmx">

</cc1:CascadingDropDown>

</div>

<cc1:CascadingDropDown ID="CascadingDropDown2" runat="server" TargetControlID="DropDownList2" Category="city" ParentControlID="DropDownList1" PromptText="请选择城市" ServiceMethod="GetDropDownContents" ServicePath="WebService.asmx" LoadingText="正在加载....">

</cc1:CascadingDropDown>

<cc1:CascadingDropDown ID="CascadingDropDown3" runat="server" TargetControlID="DropDownList3" Category="country" ParentControlID="DropDownList2" PromptText="请选择县" ServiceMethod="GetDropDownContents" ServicePath="WebService.asmx" LoadingText="正在加载...">

</cc1:CascadingDropDown>

<asp:UpdatePanel ID="UpdatePanel1" runat="server" RenderMode="Inline" UpdateMode="Conditional">

<asp:Label ID="Label1" runat="server" Text="还未选择"></asp:Label>

</ContentTemplate>

<asp:AsyncPostBackTrigger ControlID="DropDownList3" EventName="SelectedIndexChanged" />

</Triggers>

</asp:UpdatePanel>

</form>

</body>

</html>