ajax 笔记－－调用WebService实现求两数之和

        <script type="text/javascript">
        var xmlHttp;
        function createXMLHttpRequest()
        ...{
            xmlHttp = false
            
            if(window.XMLHttpRequest)//开始初始化XMLHttpRequest对象//Mozilla浏览器
            ...{
                xmlHttp = new XMLHttpRequest();
                if(xmlHttp.overrideMimeType) //设置Mime类别
                ...{           
                    xmlHttp.overrideMimeType("text/xml");
                }
            }
            else if(window.ActiveXObject)
            ...{
                try
                ...{
                    xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
                }
                catch(e)
                ...{
                    try
                    ...{
                        xmlHttp = new ActiveXObject("Micosoft.XMLHTTP");
                    }
                    catch(e)
                    ...{
                    }
                }
            }
            if(!xmlHttp)
            ...{
                //异常,创建实例失败
                window.alert("不能创建XMLHttpRequest对象实例");
                return false;
            }
        }
        function TotalURL(aa,bb)
        ...{
            createXMLHttpRequest();
            xmlHttp.open("POST",aa,true);
            xmlHttp.onreadystatechange = processRequest;
            xmlHttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
            xmlHttp.send(bb);
        }
        //处理返回信息的函数
        function processRequest()
        ...{
            if(xmlHttp.readyState == 4)//判断对象状态
            ...{
                if(xmlHttp.status == 200)//信息已经成功返回,开始处理信息
                ...{
                    var disp = document.getElementById("spnDetailDisplay");
                    var xmlDoc = xmlHttp.responseXML
                    var result = xmlDoc.lastChild.childNodes[0].nodeValue;
                    document.getElementById("total").innerHTML  = result;
                    //alert(xmlHttp.responseText);
                }
                else
                ...{
                    alert(xmlHttp.responseText);
                    //页面不正常
                    alert("你所请求的页面有异常");
                }
            }
        }
        function ExeWebService()
        ...{
            var val1 = document.getElementById("value1").value;
            var val2 = document.getElementById("value2").value;
            var url = "http://localhost/LiaoHaiBing/Total.asmx/ReturnTotal"
            var values = "arg1=" + val1 +"&arg2="+val2;
            TotalURL(url,values);
        }
        </script>

上面代码是javascript脚本．

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下面是Total.aspx的部分html代码．

<div>
                <table>
                    <tr>
                        <td>第一个值：</td>
                        <td><input type="text" id="value1"></td>
                    </tr>
                    <tr>
                        <td>第二个值：</td>
                        <td><input type="text" id="value2"></td>
                    </tr>
                    <tr>
                        <td><input value="求和" type="button" onclick="ExeWebService();"></td>
                        <td>
                            <asp:Label id="lblTotal" runat="server"></asp:Label></td>
                    </tr>
                </table>
                <div id="total">
                </div>
            </div>

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上面是添加一个WebServic，名字叫Total.asmx，完了之后添加如下代码放到　Total.asmx　代码里去．

        /**//// <summary>
        /// 返回两数之和
        /// </summary>
        /// <param name="arg1">传来的第一个参数</param>
        /// <param name="arg2">传来的第二个参数</param>
        /// <returns>ReturnTotal</returns>
        [WebMethod]
        public int ReturnTotal(int arg1,int arg2)
        ...{
            return arg1 + arg2;
        }