GridView高效分页+搜索的完整实现

Posted on 2013-03-16 19:20 星星之火116 阅读(19695) 评论(12) 编辑收藏举报

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

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

   <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：

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

#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

/// <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

/// <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

/// <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　

/// <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

/// <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

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

/// <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

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！