ASP. NET中的webservice

在分布式计算中经常要用到WebService，为了更好的学习WebService，写此文供自己记忆。

编译环境:VS2008

在项目中添加一个名称为MyWebService.asmx的Web服务，App_Code文件夹下会新增一个MyWebService.cs文件，编写代码如下:

using System;
using System.Collections;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Xml.Linq;/// <summary>
///MyWebService 的摘要说明
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
//若要允许使用 ASP.NET AJAX 从脚本中调用此 Web 服务，请取消对下行的注释。 
// [System.Web.Script.Services.ScriptService]
public class MyWebService : System.Web.Services.WebService {public MyWebService () {//如果使用设计的组件，请取消注释以下行 //InitializeComponent(); }[WebMethod]public string HelloWorld() {return "Hello World";}}

写好WebService以后，在项目上右键选择“添加Web引用”，可以给WebService起一个命名空间localhost。

添加Web引用成功如下图所示：

下面我们写客户端代码

前端代码:

<form id="form1" runat="server"><div><asp:Button ID="Button1" runat="server" Text="同步调用WebService"  /><asp:Button ID="Button2" runat="server" Text="异步调用WebService"  /><asp:Button ID="Button3" runat="server" Text="另一种异步调用WebService"  /></div>
</form>

后台代码:

using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;public partial class _Default : System.Web.UI.Page 
{protected void Page_Load(object sender, EventArgs e){       Button1.Click += new EventHandler(Button1_Click);Button2.Click += new EventHandler(Button2_Click);Button3.Click += new EventHandler(Button3_Click);}#region 同步调用void Button1_Click(object sender, EventArgs e){localhost.MyWebService mws = new localhost.MyWebService();string s = mws.HelloWorld();Response.Write("<script>alert('"+s+"')</script>");//Response.End();}#endregion#region 异步调用void Button2_Click(object sender, EventArgs e){localhost.MyWebService AsyMWS = new localhost.MyWebService();IAsyncResult asyncResult = AsyMWS.BeginHelloWorld(new AsyncCallback(CallbackFunc), "AsyncState");string s = AsyMWS.EndHelloWorld(asyncResult);Response.Write("<script>alert('" + s + "')</script>");}void CallbackFunc(IAsyncResult r){Response.Write("<script>alert('异步调用完成!')</script>");}#endregion#region 另一种异步调用void Button3_Click(object sender, EventArgs e){localhost.MyWebService AsyMWS = new localhost.MyWebService();AsyMWS.HelloWorldCompleted += new localhost.HelloWorldCompletedEventHandler(AsyMWS_HelloWorldCompleted);AsyMWS.HelloWorldAsync();}void AsyMWS_HelloWorldCompleted(object sender, localhost.HelloWorldCompletedEventArgs e){string s = e.Result;Response.Write("<script>alert('"+s+"')</script>");}#endregion
}