GridView高效分页+搜索的完整实现

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GridView高效分页+搜索的完整实现_第1张图片

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

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< 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:

GridView高效分页+搜索的完整实现_第2张图片

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

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#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

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/// <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

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/// <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

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/// <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 

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/// <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

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/// <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

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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

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/// <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

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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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