.net 下用javascript调用webservice

2008-02-22 09:35:38来源：互联网阅读 ()

.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>