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GridView高效分页和搜索功能的实现代码

  • 时间:2021-10-03 11:09 编辑: 来源: 阅读:
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摘要:GridView高效分页和搜索功能的实现代码
前言:         公司项目开发,上周的任务是做基础数据的管理。在Sharepoint2010里边内嵌asp.net的aspx页,遇到了各种各样奇葩的问题,因为之前对sharepoint只是有一些了解,但是没有设计到具体的编程工作,这一次算是初次接触吧。其中有一部分基础数据数据量很大,大致有十多万,因为是对基础数据的维护,所以还需要对数据进行列表展示,增删改查什么的,大家都知道Asp.net里边的GridView有自带的分页,但是,那个分页对于少量的数据还好,对于这种数十万的数据量而言,这种分页方式简直就是灾难。网上关于GridView高效分页的东西有很多,找了一个自己改了改。用着效果还不错,和大家分享一下。         这是分页的效果图 [img]http://files.jb51.net/file_images/article/201303/2013316222200545.png[/img]  下边就讲一下具体的实现,首先声明,这个东西是不是我原创的,只是在此基础上进行了修饰和完善。希望能给各位有所启发。           一、前台布局
[u]复制代码[/u] 代码如下:
  <div>     <div id="main">     <div id="search">        <table> <tr> <td>     <asp:Label ID="lb" runat="server" Text="姓名"></asp:Label></td> <td>     <asp:TextBox ID="SearchName" runat="server"></asp:TextBox> </td> <td>     <asp:Button ID="btnSearch" runat="server" Text="查询" onclick="PagerBtnCommand_OnClick" CommandName="search" /> </td> <td>     <asp:Button ID="btnReset" runat="server" Text="重置" onclick="btnReset_Click" /> </td> </tr> </table>     </div>     <div id="gridView">      <asp:GridView ID="UserGridView" runat="server"  AutoGenerateColumns="false">         <Columns>         <asp:TemplateField HeaderText="用户名">         <ItemTemplate>             <asp:Label ID="UserName" runat="server" Text='<%#Eval("username") %>'></asp:Label>         </ItemTemplate>         </asp:TemplateField>         <asp:TemplateField HeaderText="单位名称">         <ItemTemplate>             <asp:Label ID="DisplayName" runat="server" Text='<%#Eval("displayname") %>'></asp:Label>         </ItemTemplate>         </asp:TemplateField>         <asp:TemplateField HeaderText="组织编码">         <ItemTemplate>             <asp:Label ID="OrgCode" runat="server" Text='<%#Eval("orgcode") %>'></asp:Label>         </ItemTemplate>         </asp:TemplateField>         <asp:TemplateField HeaderText="组织名称">         <ItemTemplate>             <asp:Label ID="OrgName" runat="server" Text='<%#Eval("orgname") %>'></asp:Label>         </ItemTemplate>         </asp:TemplateField>         </Columns>         </asp:GridView>     </div>     <div id="page">     <table>      <tr>      <td>       <asp:Label ID="lbcurrentpage1" runat="server" Text="当前页:"></asp:Label>     <asp:Label ID="lbCurrentPage" runat="server" Text=""></asp:Label>     <asp:Label ID="lbFenGe" runat="server" Text="/"></asp:Label>     <asp:Label ID="lbPageCount" runat="server" Text=""></asp:Label>     </td>      <td>      <asp:Label ID="recordscount" runat="server" Text="总条数:"></asp:Label>       <asp:Label ID="lbRecordCount" runat="server" Text=""></asp:Label>     </td>     <td> <asp:Button ID="Fistpage" runat="server" CommandName="" Text="首页" OnClick="PagerBtnCommand_OnClick" /> <asp:Button ID="Prevpage" runat="server" CommandName="prev" Text="上一页"         OnClick="PagerBtnCommand_OnClick" /> <asp:Button ID="Nextpage" runat="server" CommandName="next" Text="下一页" OnClick="PagerBtnCommand_OnClick" /> <asp:Button ID="Lastpage" runat="server" CommandName="last" Text="尾页"        key="last" OnClick="PagerBtnCommand_OnClick" /> </td>     <td>     <asp:Label ID="lbjumppage" runat="server" Text="跳转到第"></asp:Label>     <asp:TextBox ID="GotoPage" runat="server" Width="25px"></asp:TextBox>     <asp:Label ID="lbye" runat="server" Text="页"></asp:Label>       <asp:Button ID="Jump" runat="server" Text="跳转" CommandName="jump" OnClick="PagerBtnCommand_OnClick" />     </td> </tr> </table>     </div>     </div>     </div>
布局的效果如下: [img]http://files.jb51.net/file_images/article/201303/2013316222456813.png[/img] 二、后台的代码实现      我会一点一点向大家讲解清楚,这个分页的原理      Members:这里主要定义几个全局的变量,主要用来记录信息的数量、页的数量和当前页
[u]复制代码[/u] 代码如下:
#region Members         const int PAGESIZE = 10;//每页显示信息数量         int PagesCount, RecordsCount;//记录总页数和信息总条数         int CurrentPage, Pages, JumpPage;//当前页,信息总页数(用来控制按钮失效),跳转页码         const string COUNT_SQL = "select count(*)  from p_user";         #endregion
Methods:   1、GetRecordsCount:该方法主要用来获取当前信息的总数,有一个sqlSearch参数,默认的为default,即初始化页面时,查询所有信息的总条数,当用户输入要搜索的用户名进行检索时,获取符合用户检索条件的信息的总条数
[u]复制代码[/u] 代码如下:
/// <summary>        /// 获取信息总数        /// </summary>        /// <param name="sqlSearch"></param>        /// <returns></returns>        public static int GetRecordsCount(string sqlRecordsCount)        {            string sqlQuery;            if (sqlRecordsCount == "default")            {                sqlQuery = COUNT_SQL;            }            else            {                sqlQuery = sqlRecordsCount;            }            int RecordCount = 0;            SqlCommand cmd = new SqlCommand(sqlQuery, Conn());            RecordCount = Convert.ToInt32(cmd.ExecuteScalar());            cmd.Connection.Close();            return RecordCount;        }
2、OverPage:该方法主要用来计算剩余页,当前设置的为每页显示10条数据,如何符合条件的数据有11条,则要显示2页
[u]复制代码[/u] 代码如下:
/// <summary>        /// 计算余页        /// </summary>        /// <returns></returns>        public int OverPage()        {            int pages = 0;            if (RecordsCount % PAGESIZE != 0)                pages = 1;            else                pages = 0;            return pages;        }
3、ModPage:该方法也是用计算余页,主要用来防止SQL执行溢出
[u]复制代码[/u] 代码如下:
/// <summary>        /// 计算余页,防止SQL语句执行时溢出查询范围        /// </summary>        /// <returns></returns>        public int ModPage()        {            int pages = 0;            if (RecordsCount % PAGESIZE == 0 && RecordsCount != 0)                pages = 1;            else                pages = 0;            return pages;        }
4、Conn:该方法用来创建数据连接对象,在使用的时候只需改成自己的数据库名即可 
[u]复制代码[/u] 代码如下:
/// <summary>         /// 数据连接对象         /// </summary>         /// <returns></returns>         public static SqlConnection Conn()         {             SqlConnection conn = new SqlConnection("data source=.;initial catalog=DB_GSL_ZCW;Integrated Security=true");             conn.Open();             return conn;         }
5、GridViewDataBind:该方法主要用来数据绑定,如果传入的参数为default则,默认的绑定所有的数据,否则,则绑定过滤过的数据
[u]复制代码[/u] 代码如下:
/// <summary>         /// GridView数据绑定,根据传入参数的不同,进行不同方式的查询,         /// </summary>         /// <param name="sqlSearch"></param>         private void GridViewDataBind(string sqlSearch)         {             CurrentPage = (int)ViewState["PageIndex"];             //从ViewState中读取页码值保存到CurrentPage变量中进行按钮失效运算             Pages = (int)ViewState["PagesCount"];             //从ViewState中读取总页参数进行按钮失效运算             //判断四个按钮(首页、上一页、下一页、尾页)状态             if (CurrentPage + 1 > 1)//当前页是否为首页             {                 Fistpage.Enabled = true;                 Prevpage.Enabled = true;             }             else             {                 Fistpage.Enabled = false;                 Prevpage.Enabled = false;             }             if (CurrentPage == Pages)//当前页是否为尾页             {                 Nextpage.Enabled = false;                 Lastpage.Enabled = false;             }             else             {                 Nextpage.Enabled = true;                 Lastpage.Enabled = true;             }             DataSet ds = new DataSet();             string sqlResult;             //根据传入参数sqlSearch进行判断,如果为default则为默认的分页查询,否则为添加了过滤条件的分页查询             if (sqlSearch == "default")             {                 sqlResult = "Select Top " + PAGESIZE + "user_serialid,username,displayname,orgcode,orgname from p_user where user_serialid not in(select top " + PAGESIZE * CurrentPage + " user_serialid from p_user order by user_serialid asc) order by user_serialid asc";             }             else             {                 sqlResult = sqlSearch;             }             SqlDataAdapter sqlAdapter = new SqlDataAdapter(sqlResult, Conn());             sqlAdapter.Fill(ds, "Result");             UserGridView.DataSource = ds.Tables["Result"].DefaultView;             UserGridView.DataBind();             //显示Label控件lbCurrentPaget和文本框控件GotoPage状态             lbCurrentPage.Text = (CurrentPage + 1).ToString();             GotoPage.Text = (CurrentPage + 1).ToString();             sqlAdapter.Dispose();         }
6、Page_Load:页面加载函数,主要是在首次进入页面时,进行初始化,默认的获取所有的信息
[u]复制代码[/u] 代码如下:
protected void Page_Load(object sender, EventArgs e)         {             if (!IsPostBack)//首次进行该页时,页面初始化             {                 RecordsCount = GetRecordsCount("default");//默认信息总数                 PagesCount = RecordsCount / PAGESIZE + OverPage();//默认的页总数                 ViewState["PagesCount"] = RecordsCount / PAGESIZE - ModPage();//保存末页索引,比页总数小1                 ViewState["PageIndex"] = 0;//保存页面初始索引从0开始                 ViewState["JumpPages"] = PagesCount;                 //保存页总数,跳页时判断用户输入数是否超出页码范围                 //显示lbPageCount、lbRecordCount的状态                 lbPageCount.Text = PagesCount.ToString();                 lbRecordCount.Text = RecordsCount.ToString();                 //判断跳页文本框失效                 if (RecordsCount <= 10)                 {                     GotoPage.Enabled = false;                 }                     GridViewDataBind("default");//调用数据绑定函数TDataBind()进行数据绑定运算             }         }
7、PagerBtnCommand_OnClick:该方法主要用来处理设计视图页的“首页”、“下一页”,“上一页”,“尾页”,“查询”按钮的Click事件,主要通过不同按钮的CommandName属性来分别处理,需要在前台为每一个按钮相应的CommandName属性赋值,如果用户点击的是“查询”按钮,这个时候需要对查询的Sql语句进行重写,加入过滤条件,即用户输入的查询的条件
[u]复制代码[/u] 代码如下:
/// <summary>         /// 页面按钮Click处理         /// </summary>         /// <param name="sender"></param>         /// <param name="e"></param>         protected void PagerBtnCommand_OnClick(object sender, EventArgs e)         {             CurrentPage = (int)ViewState["PageIndex"];             //从ViewState中读取页码值保存到CurrentPage变量中进行参数运算             Pages = (int)ViewState["PagesCount"];//从ViewState中读取总页参数运算             Button btn = sender as Button;             string sqlResult="default";             if (btn != null)             {                 string cmd = btn.CommandName;                 switch (cmd)//根据不同的CommandName做出不同的处理                 {                     case "next":                         CurrentPage++;                         break;                     case "prev":                         CurrentPage--;                         break;                     case "last":                         CurrentPage = Pages;                         break;                     case "search":                         if (!string.IsNullOrEmpty(SearchName.Text))                         {                             RecordsCount = GetRecordsCount("select count(*) from p_user where username like '" + SearchName.Text + "%'");//获取过滤后的总记录数                             PagesCount = RecordsCount / PAGESIZE + OverPage();//该变量为页总数                             ViewState["PagesCount"] = RecordsCount / PAGESIZE - ModPage();//该变量为末页索引,比页总数小1                             ViewState["PageIndex"] = 0;//保存一个为0的页面索引值到ViewState,页面索引从0开始                             ViewState["JumpPages"] = PagesCount;                             //保存PageCount到ViewState,跳页时判断用户输入数是否超出页码范围                             //显示lbPageCount、lbRecordCount的状态                             lbPageCount.Text = PagesCount.ToString();                             lbRecordCount.Text = RecordsCount.ToString();                             //判断跳页文本框失效                             if (RecordsCount <= 10)                                 GotoPage.Enabled = false;                 sqlResult = "Select Top " + PAGESIZE + "user_serialid,username,displayname,orgcode,orgname from p_user where user_serialid not in(select top " + PAGESIZE * CurrentPage + " user_serialid from p_user order by user_serialid asc) and username like '" + SearchName.Text + "%' order by user_serialid asc";                         }                         else                         {                             Response.Write("请输入您所要查找的用户姓名!");                         }                         break;                     case "jump":                        JumpPage = (int)ViewState["JumpPages"];                       //从ViewState中读取可用页数值保存到JumpPage变量中                       //判断用户输入值是否超过可用页数范围值                       if(Int32.Parse(GotoPage.Text) > JumpPage ||      Int32.Parse(GotoPage.Text) <= 0) Response.Write("<script>alert('页码范围越界!')</script>");                       else                       {                           int InputPage = Int32.Parse(GotoPage.Text.ToString()) - 1;                           //转换用户输入值保存在int型InputPage变量中                           ViewState["PageIndex"] = InputPage;                           CurrentPage = InputPage;                          //写入InputPage值到ViewState["PageIndex"]中                           sqlResult = "Select Top " + PAGESIZE + "user_serialid,username,displayname,orgcode,orgname from p_user where user_serialid not in(select top " + PAGESIZE * CurrentPage + " user_serialid from p_user order by user_serialid asc) and username like '" + SearchName.Text + "%' order by user_serialid asc";                       }                         break;                     default:                         CurrentPage = 0;                         break;                 }                 ViewState["PageIndex"] = CurrentPage;                 //将运算后的CurrentPage变量再次保存至ViewState                 GridViewDataBind(sqlResult);//调用数据绑定函数TDataBind()             }         }
8、btn_Reset_Click:该方法主要用来进行重置,用户完成一次查询之后,需要重置,才能进行下一次的查询操作
[u]复制代码[/u] 代码如下:
protected void btnReset_Click(object sender, EventArgs e)      (          RecordsCount = GetRecordsCount("default");//默认信息总数          PagesCount = RecordsCount / PAGESIZE + OverPage();//默认的页总数          ViewState["PagesCount"] = RecordsCount / PAGESIZE - ModPage();//保存末页索引,比页总数小1          ViewState["PageIndex"] = 0;//保存页面初始索引从0开始          ViewState["JumpPages"] = PagesCount;          //保存页总数,跳页时判断用户输入数是否超出页码范围          //显示lbPageCount、lbRecordCount的状态          lbPageCount.Text = PagesCount.ToString();          lbRecordCount.Text = RecordsCount.ToString();          //判断跳页文本框失效          if (RecordsCount <= 10)          {              GotoPage.Enabled = false;          }              GridViewDataBind("default");//调用数据绑定函数TDataBind()进行数据绑定运算      }
这里的高效分页方法主要用的是select top 10 Id ,Name from tb where Id not in (select top 10*N from tb order by Id asc) order by Id asc 示例中的N代表的是页数,之前原子里也有很多关于高效分页的讨论,这里就不再多说了,我个人觉得这个分页语句效果还不错,当然除此之外还有row_number()函数分页、select Max() 分页等等方法,之前也有总结过,有兴趣的朋友可以看一下我之前写的ListView和Repeater高效分页这篇文章,里边讲述的也很详细,只要你一步一步的照着去操练应该问题不大的。 这里需要解释一下的是为什么没有有数据绑定控件直接进行绑定,因为在sharepoint2010项目里边它支持的数据源控件只有XMLDataSource,所以就只有自己动手实现了。 好了今天就到这里了,希望能给大家带来些帮助吧!还请多多指教!
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