asp.net中一个linq分页实现代码

testDataContext dc = new testDataContext();
public string GetPageNum(GridView GridViewName,int pagesize,IQueryable<test> sql)
{
int page;
if (HttpContext.Current.Request.QueryString["page"] != null)
page = Convert.ToInt32(HttpContext.Current.Request.QueryString["page"]);
else
page = 1;
//var sql = from o in dc.test select o;
int total = sql.Count();//总数据量
var sqls = sql.Skip((page - 1) * pagesize).Take(pagesize);
GridViewName.DataSource = sqls;
GridViewName.DataBind();
int allpage = 0;
int next = 0;
int pre = 0;
int startcount = 0;
int endcount = 0;
string pagestr = "";
if (page < 1) { page = 1; }
//计算总页数
if (pagesize != 0)
{
allpage = (total / pagesize);
allpage = ((total % pagesize) != 0 ? allpage + 1 : allpage);
allpage = (allpage == 0 ? 1 : allpage);
}
next = page + 1;
pre = page - 1;
startcount = (page + 5) > allpage ? allpage - 9 : page - 4;//中间页起始序号
//中间页终止序号
endcount = page < 5 ? 10 : page + 5;
if (startcount < 1) { startcount = 1; } //为了避免输出的时候产生负数，设置如果小于1就从序号1开始
if (allpage < endcount) { endcount = allpage; } //页码+5的可能性就会产生最终输出序号大于总页码，那么就要将其控制在页码数之内
pagestr = "共" + allpage + "页    ";
pagestr += page > 1 ? "<a href="" + HttpContext.Current.Request.CurrentExecutionFilePath + "?page=1">首页</a>  <a href="" + HttpContext.Current.Request.CurrentExecutionFilePath + "?page=" + pre + "">上一页</a>" : "首页 上一页";
//中间页处理，这个增加时间复杂度，减小空间复杂度
for (int i = startcount; i <= endcount; i++)
{
pagestr += page == i ? "  <font color="#ff0000">" + i + "</font>" : "  <a href="" + HttpContext.Current.Request.CurrentExecutionFilePath + "?page=" + i + "">" + i + "</a>";
}
pagestr += page != allpage ? "  <a href="" + HttpContext.Current.Request.CurrentExecutionFilePath + "?page=" + next + "">下一页</a>  <a href="" + HttpContext.Current.Request.CurrentExecutionFilePath + "?page=" + allpage + "">末页</a>" : " 下一页 末页";
return pagestr;
}

public static string GetPageNum(DataTable ds,DataList datalistname,int pagesize)
{
PagedDataSource objPds = new PagedDataSource();
objPds.DataSource = ds.DefaultView;
objPds.AllowPaging = true;
int total = ds.Rows.Count;
objPds.PageSize = pagesize;
int page;
if (HttpContext.Current.Request.QueryString["page"] != null)
page = Convert.ToInt32(HttpContext.Current.Request.QueryString["page"]);
else
page = 1;
objPds.CurrentPageIndex = page - 1;
datalistname.DataSource = objPds;
datalistname.DataBind();
int allpage = 0;
int next = 0;
int pre = 0;
int startcount = 0;
int endcount = 0;
string pagestr = "";
if (page < 1) { page = 1; }
//计算总页数
if (pagesize != 0)
{
allpage = (total / pagesize);
allpage = ((total % pagesize) != 0 ? allpage + 1 : allpage);
allpage = (allpage == 0 ? 1 : allpage);
}
next = page + 1;
pre = page - 1;
startcount = (page + 5) > allpage ? allpage - 9 : page - 4;//中间页起始序号
//中间页终止序号
endcount = page < 5 ? 10 : page + 5;
if (startcount < 1) { startcount = 1; } //为了避免输出的时候产生负数，设置如果小于1就从序号1开始
if (allpage < endcount) { endcount = allpage; } //页码+5的可能性就会产生最终输出序号大于总页码，那么就要将其控制在页码数之内
pagestr = "共" + allpage + "页    ";
pagestr += page > 1 ? "<a href="" + HttpContext.Current.Request.CurrentExecutionFilePath + "?page=1">首页</a>  <a href="" + HttpContext.Current.Request.CurrentExecutionFilePath + "?page=" + pre + "">上一页</a>" : "首页 上一页";
//中间页处理，这个增加时间复杂度，减小空间复杂度
for (int i = startcount; i <= endcount; i++)
{
pagestr += page == i ? "  <font color="#ff0000">" + i + "</font>" : "  <a href="" + HttpContext.Current.Request.CurrentExecutionFilePath + "?page=" + i + "">" + i + "</a>";
}
pagestr += page != allpage ? "  <a href="" + HttpContext.Current.Request.CurrentExecutionFilePath + "?page=" + next + "">下一页</a>  <a href="" + HttpContext.Current.Request.CurrentExecutionFilePath + "?page=" + allpage + "">末页</a>" : " 下一页 末页";
return pagestr;
}