我爱Aspx >> Asp.Net >> ASP.NET 2.0客户端回调的实现分析

ASP.NET 2.0客户端回调的实现分析

在文本框输入要查找的用户名后，接着点击"回调"按钮就会发生客户端回调。这是查找到用户的显示结果

这是查找到用户的显示结果

用户不存在的显示信息：

用户不存在的显示信息

后台代码：ClientCallbacksSimple.aspx.cs

01 using System;02 using System.Data;03 using System.Configuration;04 using System.Collections;05 using System.Web;06 using System.Web.Security;07 using System.Web.UI;08 using System.Web.UI.WebControls;09 using System.Web.UI.WebControls.WebParts;10 using System.Web.UI.HtmlControls;11 using System.Data.SqlClient;12 public partial class ClientCallbacksSimple : System.Web.UI.Page, 1313 System.Web.UI.ICallbackEventHandler14 {15 protected string strUserInfo; //保存读取的用户信息16 //引发回调事件17 public void RaiseCallbackEvent(string txtFirstName)18 {19 if (txtFirstName != null)20 {21 SqlConnection conn = new SqlConnection("data source=localhost;initial 22 catalog=Northwind;integrated security=SSPI");23 conn.Open();24 SqlCommand cmd = new SqlCommand("select EmployeeID,FirstName,City,Address 2525 from Employees where FirstName=@FirstName", conn);26 cmd.Parameters.Add("@FirstName", SqlDbType.NVarChar, 10).Value = txtFirstName;27 SqlDataReader dr = cmd.ExecuteReader();28 if (dr.Read())29 {30 strUserInfo = "员工代号：" + dr["EmployeeID"] + "\r\n";31 strUserInfo += "姓名：" + dr["FirstName"] + "\r\n";32 strUserInfo += "居住城市：" + dr["City"] + "\r\n";33 strUserInfo += "地址：" + dr["Address"].ToString().Replace("\r\n","")+ "\r\n";34 strUserInfo += "服务器查询时间：" + DateTime.Now.ToLongTimeString();35 }36 else37 {38 if (String.IsNullOrEmpty(txtFirstName))39 {40 strUserInfo = "请输入姓名";41 }42 else43 {44 strUserInfo = "查无此人";45 }46 }47 cmd.Dispose();48 dr.Dispose();49 conn.Dispose();50 }51 }52 //回传回调结果53 public string GetCallbackResult()54 {55 return strUserInfo; //回传员工的基本信息56 }57 }

Ҷƪл˵?

第一页上一页1234567下一页尾页