ajax笔记 显示出所城市名称 ShowCity.aspx.cs代码

下面是cs代码

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.Text;
using GetCommand; //这是一个连接数据库的DLL

public partial class Ajax_ShowCity : System.Web.UI.Page, ICallbackEventHandler
...{
    /**//// <summary>
    /// 声明一个数据集对象
    /// </summary>
    private DataSet lookupData = null;
    protected void Page_Load(object sender, EventArgs e)
    ...{
        string js = Page.ClientScript.GetCallbackEventReference(this, "arg", "OnServerCallComplete", "ctx", "OnServerCallError", true);//这里false表示异步回调; true表示同步回调);
        StringBuilder newFunction = new StringBuilder();
        newFunction.Append("function StartAsyncCall(arg,ctx) ");
        newFunction.Append("{ ");
        newFunction.Append( js );
        newFunction.Append(" } ");
        Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "NewAsyncMethod", newFunction.ToString(), true);
        /**////
        /// 是首页上显示出所有城市出来
        ///
        this.ShowCity();
        this.lblMessage.Text = SetConnection._errorStatus;
        this.lblMessage.Text += SetConnection.status;
    }

    /**//// <summary>
    /// 显示城市
    /// </summary>
    private void ShowCity()
    ...{
        string executeString = "select CityID,CityName from City";
        GridView1.DataSource = this.GetLookupValuesFromDatabase(executeString,"City");
        this.GridView1.DataBind();
    }
    /**//// <summary>
    /// 返回一个数据集
    /// </summary>
    /// <param name="executeString">sql语句或存储过程</param>
    /// <param name="TableName">在内存中名和名称</param>
    /// <returns>ds</returns>
    private DataSet GetLookupValuesFromDatabase(string executeString,string TableName)
    ...{
        DataSet ds = GetCommand.SetConnection.getDataSet(executeString, TableName);
        return ds;
    }
    /**//// <summary>
    /// 返回回调结果
    /// </summary>
    /// <returns></returns>
    public string GetCallbackResult()
    ...{
        /**////
        /// 存放City表中的城市ID号
        ///
        StringBuilder ids = new StringBuilder();
        /**////
        /// 存放City表中的城市名称
        ///
        StringBuilder names = new StringBuilder();
        int rowCount = 0;
        int numberRows = lookupData.Tables["City"].Rows.Count;
        foreach (DataRow row in lookupData.Tables["City"].Rows)
        ...{
            rowCount++;
            if (rowCount <= numberRows)
            ...{
                ids.Append(row["CityID"].ToString());
                ids.Append("|");
                names.Append(row["CityName"].ToString());
                names.Append("|");
            }
            //if (rowCount < numberRows)
            //{
            //}
        }
        string returnData = string.Format("{0}~{1}", ids.ToString(), names.ToString());
        return returnData;
    }
    public void RaiseCallbackEvent(string eventArgument)
    ...{
        System.Threading.Thread.Sleep(2000);
        string executeString = "select CityID,CityName from City";
        lookupData = this.GetLookupValuesFromDatabase(executeString, "City");        
    }
}

 下面是html里的代码