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Linq实现GridView高效分页（Skip() and take()）

news 来源：原创 2024/5/20 22:02:22

1.页面代码

Code
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <asp:GridView  ID="grdView"  runat="server">
    </asp:GridView>
            <asp:Label runat="server" ID="lblRowsCount"></asp:Label>
            <asp:Button ID="btnFirst" Text="首页" runat="server" OnClick="btnFirst_Click">
            </asp:Button>
            <asp:Button ID="btnPre" Text="上一页" runat="server" OnClick="btnPre_Click">
            </asp:Button>
            <asp:Button ID="btnNext" Text="下一页" runat="server" OnClick="btnNext_Click">
            </asp:Button>
            <asp:Button ID="btnLast" Text="末页" runat="server" OnClick="btnLast_Click">
            </asp:Button>
            <asp:Label runat="server" ID="lblPagesIndex"></asp:Label>
            <asp:Label runat="server" ID="Label2" Text="转到第："></asp:Label>
            <asp:TextBox ID="txt" runat="server"  Width="40px" ></asp:TextBox>
            <asp:Label runat="server" ID="Label1" Text="页"></asp:Label>
            <asp:Button ID="btnSkip" Text="转到" runat="server" OnClick="btnSkip_Click"></asp:Button>

    </form>
</body>
</html>

2.后台代码

Code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using BaiChang.Node;

public partial class admin_Club_User_test : System.Web.UI.Page
{
    NodeContext nc = new NodeContext(Utils.BC_ConnectionString);

    protected void Page_Load(object sender, EventArgs e)
    {
        this.pageSize = 20;
        if (!IsPostBack)
        {
            SetFirstPage();
        }
    }

    protected override void OnPreRender(EventArgs e)
    {
        base.OnPreRender(e);
        if (CurrentPage == 1)
        {
            btnFirst.Enabled = false;
            btnPre.Enabled = false;
        }
        else
        {
            btnFirst.Enabled = true;
            btnPre.Enabled = true;
        }
        if (CurrentPage == PageCount)
        {
            btnNext.Enabled = false;
            btnLast.Enabled = false;
        }

        else
        {
            btnNext.Enabled = true;
            btnLast.Enabled = true;
        }
        GetCurrent(CurrentPage, PageSize);
        lblRowsCount.Text = string.Format("共：{0} 位会员", RowsCount);
        lblPagesIndex.Text = string.Format("页次：{0}/{1}", CurrentPage, PageCount);
    }

    protected void btnFirst_Click(object sender, EventArgs e)
    {
        SetFirstPage();
    }

    protected void btnLast_Click(object sender, EventArgs e)
    {
        SetLastPage();
    }

    protected void btnPre_Click(object sender,EventArgs e)
    {
        if (ViewState["currentPage"] == null)
        {
            this.currentPage = 1;
        }
        else
        {
            this.currentPage = int.Parse(ViewState["currentPage"].ToString()) - 1;
            ViewState["currentPage"] = currentPage;
        }
    }

    protected void btnNext_Click(object sender, EventArgs e)
    {
        if (ViewState["currentPage"] != null)
        {
            this.currentPage = int.Parse(ViewState["currentPage"].ToString()) + 1;
            ViewState["currentPage"] = currentPage;
        }
    }

    protected void btnSkip_Click(object sender, EventArgs e)
    {
        if (txt.Text.Trim() == string.Empty)
        {
            return;
        }
        else
        {
            int skipPage = int.Parse(txt.Text.Trim());
            if (skipPage > PageCount)
            {
                txt.Text = string.Empty;
                return;
            }
            else
            {
                this.currentPage = skipPage;
                ViewState["currentPage"] = currentPage;
            }
        }
    }

    void SetFirstPage()
    {
        this.currentPage = 1;
        ViewState["currentPage"] = currentPage;
    }

    void SetLastPage()
    {
        this.currentPage = PageCount;
        ViewState["currentPage"] = currentPage;
    }

    IEnumerable<BC_Club> Select()
    {
        var clubs = nc.BC_Club.Where(m => m.FilterState != 99);
        return clubs;
    }

    void GetCurrent(int start,int rows)
    {
        grdView.Rows.Clear();
        grdView.DataSource = Select().Skip(pageSize * (start - 1)).Take(rows).ToList();
        grdView.DataBind();
    }

    private int RowsCount
    {
        get
        {
            if( ViewState["RowsCount"]==null)
                return Select().Count();
            else
                return int.Parse(ViewState["RowsCount"].ToString());

        }
    }

    private int pageSize;
    private int PageSize
    {
        set { value = this.pageSize; }
        get { return pageSize; }
    }

    private int currentPage;
    private int CurrentPage
    {
        set { value = this.currentPage; }
        get { return this.currentPage; }
    }

    private int PageCount
    {
        get { return (int)Math.Ceiling((double)RowsCount / PageSize); }
    }


}

注释：

转载于:https://www.cnblogs.com/extensivewang/archive/2009/09/28/1575934.html