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.net 下用javascript调用webservice

文章类别:Asp.net | 发表日期:2008-10-5 22:10:03

.net 下用javascript调用webservice的话,要用到webservice behavior。下面以一个例子讲解之,比较简单

1 、首先,要创建一个webservice,比如

<%@ WebService Language="C#" class=MyMath %>
using System;
using System.Web.Services;
public class MyMath {
[WebMethod]
public int add(int a, int b)
{
return a + b;
}
[WebMethod]
public int subtract(int a, int b)
{
return a - b;
}
}
然后发布,先得到其wsdl。
2、首先,我们要下载webbehavior.htc这个文件(可以到http://msdn.microsoft.com/downloads/samples/internet/behaviors/library/webservice/default.asp.)
去下载,然后放到你的web当前目录下
然后在要调用webserice的页面中,修改如下
<body>
<div id="addservice" style="behavior:url(webservice.htc)"></div>
</body>
这里我们将div id命名为有意义的名称,并且指定style为 webservice行为。接着,我们要书写javascript来调用webserice了:
首先,我们在javascript中,调用其wsdladdservice.useService("http://localhost/services/math.asmx?WSDL","MyMath");
使用id.useService(WSDLL路径,简单的命名方式);
我们之前设定的id是addservice,而为了给客户端调用方便,我们这里起了名称,叫MyMath。而为了保证能正确调用webserice,必须在body里的onload事件里,马上加载处理webservice调用的javascript,如下
<script language="JavaScript">
function init()
{
addservice.useService("http://localhost/services/math.asmx?WSDL","MyMath"); }
</script>
<body onload="init()">
<div id="service" style="behavior:url(webservice.htc)">
</div>
</body>
 
 在上面,我们通过webservice行为,首先得到了返回webservice的wsdl,接下来我们要进行调用了,调用的格式如下:   iCallID = id.FriendlyName.callService([CallbackHandler,] "MethodName",  Param1, Param2, ...);
这里id是我们在div里设置的id,而FridndbyName是我们刚才为方面而起的命,这里就是MyMath了,而CallbackHandler是使用回调函数的过程名,如果无设置的话,则默认是使用onresult所调用的方法来进行处理,下文会讲到,而param1,,param2等则是说传入的参数了,如:
<SCRIPT language="JavaScript">
// All these variables must be global,
// because they are used in both init() and onresult().
var iCallID = 0;
var intA = 5;
var intB = 6;
function init()
{
// Establish the friendly name "MyMath" for the WebServiceURL
service.useService("/services/math.asmx?WSDL","MyMath");
// The following method doesn't specify a callback handler, so onWSresult() is used
iCallID = service.MyMath.callService("add", intA, intB);
}
function onWSresult()
{
// if there is an error, and the call came from the call() in init()
if((event.result.error)&&(iCallID==event.result.id))
{
// Pull the error information from the event.result.errorDetail properties
var xfaultcode   = event.result.errorDetail.code;
var xfaultstring = event.result.errorDetail.string;
var xfaultsoap   = event.result.errorDetail.raw;
// Add code to handle specific error codes here
}
// if there was no error, and the call came from the call() in init()
else if((!event.result.error) && (iCallID == event.result.id))
{
// Show the arithmetic!
alert(intA + ' + ' + intB + ' = ' + event.result.value);
}
else
{
alert("Something else fired the event!");
}
}
</SCRIPT>
<body onload="init()">
<div id="service" style="behavior:url(webservice.htc)" onresult="onWSresult()">
</div>
</body>
 
注意,用onresult方式返回的话,要在div部分的onresult中指定处理的方法,这里是用onWsresult()方法,其中根据返回的信息来判断是否出错,出错的话则显示。   
  如果用回调的话,则如下处理
<SCRIPT language="JavaScript">
// All these variables must be global,
// because they are used in both init() and onResult().
var iCallID = 0;
var intA = 5;
var intB = 6;
function init()
{
// Establish the friendly name "MyMath" for the WebServiceURL
service.useService("/services/math.asmx?WSDL","MyMath");
// The following uses a callback handler named "mathResults"
iCallID = service.MyMath.callService(mathResults, "add", intA, intB);
}
function mathResults(result)
{
// if there is an error, and the call came from the call() in init()
if(result.error)
{
// Pull the error information from the event.result.errorDetail properties
var xfaultcode   = result.errorDetail.code;
var xfaultstring = result.errorDetail.string;
var xfaultsoap   = result.errorDetail.raw;
// Add code to handle specific error codes here
}
// if there was no error
else
{
// Show the arithmetic
alert(intA + ' + ' + intB + " = " + result.value);
}
}
</SCRIPT>
<body onload="init()">
<div id="service" style="behavior:url(webservice.htc)">
</div>
</body>