clientcallbacks.aspx.cs

《圣殿祭司的ASP.NET 2.0开发详解——使用C#》光盘内容.包含了书籍所含的源代码.非常经典的一本asp.net2.0的书籍

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class ClientCallbacks : System.Web.UI.Page,ICallbackEventHandler
{
	protected string txtUserInfo;	//用户基本信息

	protected void Page_Load(object sender, EventArgs e)
	{
		//动态注册JavaScript
		String cbReference = Page.ClientScript.GetCallbackEventReference(this, "arg", "ReceiveServerData", "context");
		String callbackScript;
		callbackScript = "function CallServer(arg, context)" + "{ " + cbReference + "} ;";
		Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "CallServer", callbackScript, true);
	}

	//引发Callback事件处理
	public void RaiseCallbackEvent(string txtFirstName)
	{
		if (txtFirstName != null)
		{
			SqlConnection conn = new SqlConnection("data source=.;initial catalog=Northwind;user id=sa;password=test");
			conn.Open();

			SqlCommand cmd = new SqlCommand("select EmployeeID,FirstName,City,Address from Employees where FirstName=@FirstName", conn);
			cmd.Parameters.Add("@FirstName", SqlDbType.NVarChar, 10).Value = txtFirstName;
			SqlDataReader dr = cmd.ExecuteReader();

			if (dr.Read())
			{
				txtUserInfo = "员工代号：" + dr["EmployeeID"] + "  ,";
				txtUserInfo += "姓名：" + dr["FirstName"] + "  ,";
				txtUserInfo += "居住城市：" + dr["City"] + "  ,";
				txtUserInfo += "地址：" + dr["Address"].ToString().Replace("\r\n","") + "  ,";
				txtUserInfo += "服务器查询时间：" + DateTime.Now.ToLongTimeString();
			}
			else
			{
				if (String.IsNullOrEmpty(txtFirstName))
				{
					txtUserInfo = "请输入姓名";
				}
				else
				{
					txtUserInfo = "查无此人！";
				}
			}

			cmd.Dispose();
			dr.Dispose();
			conn.Dispose();
		}
	}

	//返回Callback结果
	public string GetCallbackResult()
	{
		return txtUserInfo;		//返回员工基本信息
	}
}