ISPOSTBACK .NET

来源：互联网发布：编程源代码是什么意思编辑：程序博客网时间：2024/06/08 17:28

通过图书管理系统项目的开发，深刻体会到在ispostback的作用，他就是“在页面第一次加载” 的意思，否则控件的值一旦在pageload里一旦赋值，在其他地方想修改，则该控件的值会坚持不变，还是原来的值。酷比，让我调试了一个下午。调试正确后给出下面的主要代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Tushu.BLL;
using Tushu.Model;

namespace Tushu.Web.Admin.reader
{
    public partial class SetReader : System.Web.UI.Page
    {
        tb_duzhe duzhemodel = new tb_duzhe();
        tb_duzhemanager duzhebll = new tb_duzhemanager();
        int Id;

        protected void Page_Load(object sender, EventArgs e)
        {
            Id = Convert.ToInt32(base.Request.QueryString["Id"].ToString());
            duzhemodel = duzhebll.GetModel(Id);
            if (!IsPostBack)
            {
                this.Load_Oldvalue();
            }

}

        private void Load_Oldvalue()
        {

            txt_name.Text = duzhemodel.name;
            txt_shixiaoriqi.Text = duzhemodel.shixiaoriqi.ToString();
            txt_xibie.Text = duzhemodel.xibie;
            txt_xuehao.Text = duzhemodel.xuehao;
            txt_xueyuan.Text = duzhemodel.xueyuan;

            if (duzhemodel.duzheleixing == "研究生") {
                rbl_duzheleixing.SelectedValue = "研究生";
            }
            else if (duzhemodel.duzheleixing == "本科生")
            {
                rbl_duzheleixing.SelectedValue = "本科生";
            }else{
                rbl_duzheleixing.SelectedValue = "博士生";
            }

if(duzhemodel.jieyuedengji=="等级一"){

rbl_jieyuedengji.SelectedValue = "等级一";

            }else{
                rbl_jieyuedengji.SelectedValue = "等级二";
            }

            if(duzhemodel.sex=="男"){
                rbl_sex.SelectedValue = "男";
            }else{

rbl_sex.SelectedValue = "女";
}

}

        protected void btnAlter_Click(object sender, ImageClickEventArgs e)
        {

            duzhemodel.duzheleixing = rbl_duzheleixing.SelectedValue.ToString();
            duzhemodel.jieyuedengji = rbl_jieyuedengji.Text.ToString();
            duzhemodel.name = txt_name.Text.ToString();
            duzhemodel.password = duzhemodel.password;
            duzhemodel.sex = rbl_sex.Text.ToString();
            duzhemodel.shixiaoriqi = Convert.ToDateTime(txt_shixiaoriqi.Text.ToString());
            duzhemodel.xibie = txt_xibie.Text.ToString();
            duzhemodel.xuehao = txt_xuehao.Text.ToString();
            duzhemodel.xueyuan = txt_xueyuan.Text.ToString();

            try
            {
                if (duzhebll.Update(duzhemodel))
                {
                    Response.Write(" <script language=javascript>alert('恭喜你！修改成功'); window.window.location.href='readerlist.aspx';</script> ");
                }
                else
                {
                    Response.Write(" <script language=javascript>alert('学号已经存在'); window.window.location.href='readerlist.aspx';</script> ");
                }
            }
            catch
            {
                Response.Write(" <script language=javascript>alert('修改失败'); window.window.location.href='readerlist.aspx';</script> ");

}

}
}