在JavaScript中调用ASP.NET WebService的简单方法

时间：2010-09-15 来源：行万里路责任创新执着

客户端 JavaScript 调用 ASP.NET WebService 的方法除了采用 WebServer.htc 和构造 SOAPAction 的方法外，下面介绍一个采用 Ajax 调用的简单方法，并且可以传递参数。其实，ASP.NET WebService 就是一个网站，所以，Request 对象是可用的，这样，传递参数就很容易了。下面是一个WebService1.asmx的代码

ASMX 代码

<%@ WebService Language="C#" CodeBehind="WebService1.asmx.cs" Class="WebService1" %>

C# 代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Data;

  /// <summary>
  /// Summary description for WebService1
  /// </summary>
  [WebService(Namespace = "http://tempuri.org/")]
  [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
  [System.ComponentModel.ToolboxItem(false)]
  // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
  // [System.Web.Script.Services.ScriptService]
  public class WebService1 : System.Web.Services.WebService
  {
    [WebMethod]
    // 字符串返回测试
    public string GetServerTime()
    {
      return "当前服务器时间：" + DateTime.Now.ToString();
    }

    [WebMethod]
    // long 类型返回测试
    public long GetServerTimeTicks()
    {
      return DateTime.Now.Ticks;
    }

    [WebMethod]
    // Datatable返回测试
    public DataTable GetTestDataTable()
    {
      DataTable dt = new DataTable("TestTable");
      DataRow dr;
      dt.Columns.Add(new DataColumn("id", typeof(Int32)));
      dt.Columns.Add(new DataColumn("text", typeof(string)));
      for (int i = 0; i < 6; i++)
      {
        dr = dt.NewRow();
        dr[0] = i;
        dr[1] = "列表项目 " + i.ToString();
        dt.Rows.Add(dr);
      }
      return dt;
    }

    [WebMethod]
    // List 类型测试
    public List<User> GetTestUser()
    {
      //传递参数传测试
      string param = this.Context.Request.QueryString["param"];
      if (param == null) param= this.Context.Request.Form["param1"];
      List<User> u_list = new List<User>();
      for (int i = 0; i < 10; i++)
      {
        User u = new User();
        u.Name = "LoginName" + i.ToString() + " param = " + param;
        u.Title = "孟宪会" + i.ToString();
        u_list.Add(u);
      }
      return u_list;
    }

    //定义一个对象 User
    public class User
    {
      public String Name { get; set; }
      public String Title { get; set; }
    }
  }

客户端调用的代码：

HTML 代码

<!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>JavaScript 调用 ASP.NET Web 服务测试</title>
  <script type="text/javascript">
    var xmlHttp = null;
    function createXMLHttpRequest() {
      try {
        if (window.XMLHttpRequest)
          xmlHttp = new XMLHttpRequest();
        else if (window.ActiveXObject)
          xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch (ex) { }
    }

    function AsynRequest() {
      createXMLHttpRequest();
      if (xmlHttp == null) {
        alert("不能创建 XmlHttpRequest 对象");
        return;
      }
      xmlHttp.open("GET", "WebService1.asmx/GetTestUser?param=net_lover", true);
      xmlHttp.setRequestHeader("Connection", "close");
      xmlHttp.onreadystatechange = function () {
        if (xmlHttp.readyState == 4) {
          if (xmlHttp.status == 200) {
            var userList = xmlHttp.responseXML.getElementsByTagName("User");
            for (i = 0; i < userList.length; i++) {
              document.getElementById("get1").innerHTML += userList[i].getElementsByTagName("Name")[0].firstChild.nodeValue + "：";
              document.getElementById("get1").innerHTML += userList[i].getElementsByTagName("Title")[0].firstChild.nodeValue + "<br/>";
            }
          }
        }
      };
      xmlHttp.send();
    }

    function AsynPostRequest() {
      createXMLHttpRequest();
      if (xmlHttp == null) {
        alert("不能创建 XmlHttpRequest 对象");
        return;
      }
      var data = "param1=abc";
      xmlHttp.open("POST", "WebService1.asmx/GetTestUser?t=" + Date.parse(new Date()), true);
      xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
      xmlHttp.setRequestHeader("Content-length", data.length);
      xmlHttp.setRequestHeader("Connection", "close");
      xmlHttp.onreadystatechange = function () {
        if (xmlHttp.readyState == 4) {
          if (xmlHttp.status == 200) {
            var userList = xmlHttp.responseXML.getElementsByTagName("User");
            for (i = 0; i < userList.length; i++) {
              document.getElementById("post1").innerHTML += userList[i].getElementsByTagName("Name")[0].firstChild.nodeValue + "：";
              document.getElementById("post1").innerHTML += userList[i].getElementsByTagName("Title")[0].firstChild.nodeValue + "<br/>";
            }
          }
        }
      };
      xmlHttp.send(data);
    }
  </script>
</head>
<body>
<input type="button" value="GET 方法调用" onclick="AsynRequest()" />
<input type="button" value="POST方法调用" onclick="AsynPostRequest()" />
<div id="get1"></div>
<div id="post1"></div>
</body>
</html>

需要注意的是：使用此方法需要在web.config里加入以下的配置：

web.config 代码

<system.web>
  <webServices>
    <protocols>
      <add name = "HttpPost" />
      <add name = "HttpGet" />
    </protocols>
  </webServices>
</system.web>