asp.net access添加返回自递增id的实现方法

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.OleDb;    

public partial class test : System.Web.UI.Page    
{    
    protected void Page_Load(object sender, EventArgs e)    
    {    

    }    

    /// <summary>    
    /// 申明    
    /// </summary>    
    protected ArrayList alFieldItems = new ArrayList(10);    

    //不用new初始化该对象，将产生未处理的“System.NullReferenceException”类型的异常    
    protected OleDbCommand cmd = new OleDbCommand();    
    protected string tableName = string.Empty;    
    protected string fieldName = string.Empty;    
    protected string sqlText = string.Empty;    

    /// <summary>    
    /// 产生OleDbCommand对象所需的参数    
    /// </summary>    
    protected void GenParameters()    
    {    
        OleDbCommand oleCmd = (OleDbCommand)cmd;    
        if (this.alFieldItems.Count > 0)    
        {    
            for (int i = 0; i < alFieldItems.Count; i++)    
            {    
               oleCmd.Parameters.AddWithValue("@para" + i.ToString(),((DbKeyItem)alFieldItems[i]).fieldValue.ToString());    
            }    
        }    
    }    

    /// <summary>    
    /// 数据表中的字段属性：字段名，字段值    
    /// </summary>    
    public class DbKeyItem    
    {    

        /// <summary>    
        /// 字段名称    
        /// </summary>    
        public string fieldName;    

        /// <summary>    
        /// 字段值    
        /// </summary>    
        public string fieldValue;    

        public DbKeyItem(string _fieldName, object _fieldValue)    
        {    
            this.fieldName = _fieldName;    
            this.fieldValue = _fieldValue.ToString();    
        }    
    }    

    /// <summary>    
    /// 添加一个字段/值对到数组中    
    /// </summary>    
    public void AddFieldItem(string _fieldName, object _fieldValue)    
    {    
        _fieldName = "[" + _fieldName + "]";    
        //遍历看是否已经存在字段名    
        for (int i = 0; i < this.alFieldItems.Count; i++)    
        {    
            if (((DbKeyItem)this.alFieldItems[i]).fieldName == _fieldName)    
            {    
                throw new ArgumentException("字段已经存在");    
            }    
        }    
        this.alFieldItems.Add(new DbKeyItem(_fieldName, _fieldValue));    
    }    

    /// <summary>    
    /// 根据当前alFieldItem数组添加一条记录，并返回添加后的ID    
    /// </summary>    
    /// <param name="_tableName">要插入数据的表名</param>    
    /// <returns>返回添加后的ID</returns>    
    public int insert(string _tableName)    
    {    
        this.tableName = _tableName;    
        this.fieldName = string.Empty;    
        this.sqlText = "insert into " + this.tableName + "(";    
        string temValue = " values(";    
        for (int i = 0; i < this.alFieldItems.Count; i++)    
        {    
            this.sqlText += ((DbKeyItem)alFieldItems[i]).fieldName + ",";    
            temValue += "@para" + i.ToString() + ",";    
        }    
        //分别去掉,    
        this.sqlText = Input.CutComma(sqlText) + ")" + Input.CutComma(temValue) + ")" ;    

        //定义连接字符串    
        string myString = "Provider=Microsoft.Jet.OleDb.4.0;Data Source=" + Server.MapPath("App_Data/mycms.mdb");    
        OleDbConnection conn = new OleDbConnection(myString);    
        conn.Open();    
        this.cmd.Connection = conn;    
        this.cmd.CommandText = this.sqlText;    
        this.GenParameters();    
        try   
        {    
            this.cmd.ExecuteNonQuery();    
        }    
        catch (Exception ex)    
        {    
            //弹出错误信息，仅仅是为了帮助调试，可以throw new Exception(ex.Message)    
            common.salert(ex.Message);    

        }    
        int id = 0;    
        try   
        {    
            cmd.CommandText = "select @@identity as id";    
            id = Convert.ToInt32(cmd.ExecuteScalar());    
        }    
        catch (Exception ex)    
        {    
            common.salert(ex.Message);    
        }    
        conn.Close();    
        return id;    

    }    

    protected void btnOk_Click(object sender, EventArgs e)    
    {    
        string name_    = this.tbxUseName.Text.Trim();    
        string webname_ = this.tbxWebName.Text.Trim();    
        string url_ = this.tbxUrl.Text.Trim();    
        AddFieldItem("news_Title", name_);    
        AddFieldItem("news_Source",webname_);    
        AddFieldItem("news_Anthor",url_);    
        common.salert("添加成功，添加后的ID为" + insert("db_news").ToString());     
    }    
}