如何：从 Web 服务客户端上进行异步调用
<%@ Page Language="C#" %><%@ Import Namespace="System.Net" %><html> <script language="C#" runat="server"> void EnterBtn_Click(Object Src, EventArgs E) 
{
MyMath.Math math = new MyMath.Math(); // Call to Add Web service method asynchronously // and then wait for it to complete. IAsyncResult result = math.BeginAdd(Convert.ToInt32(Num1.Text), Convert.ToInt32(Num2.Text), null, null); // Wait for asynchronous call to complete. result.AsyncWaitHandle.WaitOne(); // Complete the asynchronous call to Add Web service method. float total = math.EndAdd(result); // Display results in a Label control. Total.Text = "Total: " + total.ToString();
} </script><body> <form action="MathClient.aspx" runat=server> <font face="Verdana"> Enter the two numbers you want to add and then press the Total button. <p> Number 1: <asp:textbox id="Num1" runat=server/> + Number 2: <asp:textbox id="Num2" runat=server/> = <asp:button id="Total_Button" text="Total" OnClick="EnterBtn_Click" runat=server/> <p> <asp:label id="Total" runat=server/> </font> </form></body></html>