ASP.NET high-performance paging code

I have been struggling with paging recently. I remember that I posted a method to modify DW ASP paging before, and later wrote a manual ASP paging. Now that I enter .NET, of course I have to cooperate with stored procedures to create pure manual high-performance paging.

Why is it called high performance? Why do we need to build it manually instead of using the existing paging controls of .NET? This goes back to when I modified DW ASP paging, and I didn’t know much about programming at that time. I only know how to fix things, let alone talk about performance issues. I was very upset at the time, so I asked my personal technical director, Mr. Zhang, to help me take a look. At that time, Mr. Zhang looked at me with a disdainful look. , and said: Is it worth it?

Then I hand-created ASP paging and couldn’t do it anymore. Mr. Zhang threw me a bunch of .NET code: Study it yourself. Then he added another sentence Words: Use .NET to do it, you can get it done in just a few words, no need to worry about it.

Later I found that the previous paging process was to read the entire data set before doing paging processing. Once the amount of data is too large, , the processing will be very slow, or even the server crashes. Then the previous paging cannot be scrolled like a cursor, it is always fixed in a group, and it is impossible to achieve the effect of the current page number in the middle.

Let’s talk about it next. NET's paging control, it can indeed be solved in a few words, but the flaw is the first problem I found, which is that it is inefficient to read all the data and then process it, so I finally started to build ASP.NET purely by hand. High-performance paging.

The first is the stored procedure, which only takes out the data I need. If the number of pages exceeds the total number of data, it automatically returns the record of the last page:

set ANSI_NULLS ON 
set QUOTED_IDENTIFIER ON 
GO 
-- ============================================= 
-- Author: Clear 
-- Create date: 2007-01-30 
-- Description: 高性能分页 
-- ============================================= 
Alter PROCEDURE [dbo].[Tag_Page_Name_Select] 
-- 传入最大显示纪录数和当前页码 
    @MaxPageSize int, 
    @PageNum int, 
-- 设置一个输出参数返回总纪录数供分页列表使用 
    @Count int output 
AS 
BEGIN 
    SET NOCOUNT ON; 

   DECLARE 
-- 定义排序名称参数 
        @Name nvarchar(50), 
-- 定义游标位置 
        @Cursor int 
-- 首先得到纪录总数 
   Select @Count = count(tag_Name) 
     FROM [viewdatabase0716].[dbo].[view_tag]; 
-- 定义游标需要开始的位置 
    Set @Cursor = @MaxPageSize*(@PageNum-1)+1 
-- 如果游标大于纪录总数将游标放到最后一页开始的位置 
    IF @Cursor > @Count 
    BEGIN 
-- 如果最后一页与最大每次纪录数相等，返回最后整页 
        IF @Count % @MaxPageSize = 0 
            Set @Cursor = @Count - @MaxPageSize + 1 
-- 否则返回最后一页剩下的纪录 
        ELSE 
            Set @Cursor = @Count - (@Count % @MaxPageSize) + 1 
    END 
-- 将指针指到该页开始 
    Set Rowcount @Cursor 
-- 得到纪录开始的位置 
    Select @Name = tag_Name 
     FROM [viewdatabase0716].[dbo].[view_tag] 
    orDER BY tag_Name; 
-- 设置开始位置 
    Set Rowcount @MaxPageSize 
-- 得到该页纪录 
        Select *  
        From [viewdatabase0716].[dbo].[view_tag] 
        Where tag_Name >= @Name 
        order By tag_Name 

    Set Rowcount 0 
END

Then there is the paging control (... is the omitted method of generating HTML code):

using System.Data; 
using System.Configuration; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 
using System.Text; 

/// <summary> 
/// 扩展连接字符串 
/// </summary> 
public class ExStringBuilder 
{ 
    private StringBuilder InsertString; 
    private StringBuilder PageString; 
    private int PrivatePageNum = 1; 
    private int PrivateMaxPageSize = 25; 
    private int PrivateMaxPages = 10; 
    private int PrivateCount; 
    private int PrivateAllPage; 
    public ExStringBuilder() 
    { 
        InsertString = new StringBuilder(""); 
    } 
    /// <summary> 
    /// 得到生成的HTML 
    /// </summary> 
    public string GetHtml 
    { 
        get 
        { 
            return InsertString.ToString(); 
        } 
    } 
    /// <summary> 
    /// 得到生成的分页HTML 
    /// </summary> 
    public string GetPageHtml 
    { 
        get 
        { 
            return PageString.ToString(); 
        } 
    } 
    /// <summary> 
    /// 设置或获取目前页数 
    /// </summary> 
    public int PageNum 
    { 
        get 
        { 
            return PrivatePageNum; 
        } 
        set 
        { 
            if (value >= 1) 
            { 
                PrivatePageNum = value; 
            } 
        } 
    } 
    /// <summary> 
    /// 设置或获取最大分页数 
    /// </summary> 
    public int MaxPageSize 
    { 
        get 
        { 
            return PrivateMaxPageSize; 
        } 
        set 
        { 
            if (value >= 1) 
            { 
                PrivateMaxPageSize = value; 
            } 
        } 
    } 
    /// <summary> 
    /// 设置或获取每次显示最大页数 
    /// </summary> 
    public int MaxPages 
    { 
        get 
        { 
            return PrivateMaxPages; 
        } 
        set 
        { 
            PrivateMaxPages = value; 
        } 
    } 
    /// <summary> 
    /// 设置或获取数据总数 
    /// </summary> 
    public int DateCount 
    { 
        get 
        { 
            return PrivateCount; 
        } 
        set 
        { 
            PrivateCount = value; 
        } 
    } 
    /// <summary> 
    /// 获取数据总页数 
    /// </summary> 
    public int AllPage 
    { 
        get 
        { 
            return PrivateAllPage; 
        } 
    } 
    /// <summary> 
    /// 初始化分页 
    /// </summary> 
    public void Pagination() 
    { 
        PageString = new StringBuilder(""); 
//得到总页数 
        PrivateAllPage = (int)Math.Ceiling((decimal)PrivateCount / (decimal)PrivateMaxPageSize); 
//防止上标或下标越界 
        if (PrivatePageNum > PrivateAllPage) 
        { 
            PrivatePageNum = PrivateAllPage; 
        } 
//滚动游标分页方式 
        int LeftRange, RightRange, LeftStart, RightEnd; 
        LeftRange = (PrivateMaxPages + 1) / 2-1; 
        RightRange = (PrivateMaxPages + 1) / 2; 
        if (PrivateMaxPages >= PrivateAllPage) 
        { 
            LeftStart = 1; 
            RightEnd = PrivateAllPage; 
        } 
        else 
        { 
            if (PrivatePageNum <= LeftRange) 
            { 
                LeftStart = 1; 
                RightEnd = LeftStart + PrivateMaxPages - 1; 
            } 
            else if (PrivateAllPage - PrivatePageNum < RightRange) 
            { 
                RightEnd = PrivateAllPage; 
                LeftStart = RightEnd - PrivateMaxPages + 1; 
            } 
            else 
            { 
                LeftStart = PrivatePageNum - LeftRange; 
                RightEnd = PrivatePageNum + RightRange; 
            } 
        } 

//生成页码列表统计 
        PageString.Append(...); 

        StringBuilder PreviousString = new StringBuilder(""); 
//如果在第一页 
        if (PrivatePageNum > 1) 
        { 
            ... 
        } 
        else 
        { 
            ... 
        } 
//如果在第一组分页 
        if (PrivatePageNum > PrivateMaxPages) 
        { 
            ... 
        } 
        else 
        { 
            ... 
        } 
        PageString.Append(PreviousString); 
//生成中间页 
        for (int i = LeftStart; i <= RightEnd; i++) 
        { 
//为当前页时 
            if (i == PrivatePageNum) 
            { 
                ... 
            } 
            else 
            { 
                ... 
            } 
        } 
        StringBuilder LastString = new StringBuilder(""); 
//如果在最后一页 
        if (PrivatePageNum < PrivateAllPage) 
        { 
            ... 
        } 
        else 
        { 
            ... 
        } 
//如果在最后一组 
        if ((PrivatePageNum + PrivateMaxPages) < PrivateAllPage) 
        { 
            ... 
        } 
        else 
        { 
            ... 
        } 
        PageString.Append(LastString); 
    } 
    /// <summary> 
    /// 生成Tag分类表格 
    /// </summary> 
    public void TagTable(ExDataRow myExDataRow) 
    { 
        InsertString.Append(...); 
    }

Calling method:

//得到分页设置并放入Session 
        ExRequest myExRequest = new ExRequest(); 
        myExRequest.PageSession("Tag_", new string[] { "page", "size" }); 
//生成Tag分页 
        ExStringBuilder Tag = new ExStringBuilder(); 
        //设置每次显示多少条纪录 
        Tag.MaxPageSize = Convert.ToInt32(Session["Tag_size"]); 
        //设置最多显示多少页码 
        Tag.MaxPages = 9; 
        //设置当前为第几页 
        Tag.PageNum = Convert.ToInt32(Session["Tag_page"]); 
        string[][] myNamenValue = new string[2][]{ 
            new string[]{"MaxPageSize","PageNum","Count"}, 
            new string[]{Tag.MaxPageSize.ToString(),Tag.PageNum.ToString()} 
        }; 
//调用存储过程 
        DataTable myDataTable = mySQL.BatchGetDB("Tag_Page_Name_Select", myNamenValue, "Count"); 
        Tag.DateCount = (int)mySQL.OutputCommand.Parameters["@Count"].Value; 
        Tag.Pagination(); 

        HeadPage.InnerHtml = FootPage.InnerHtml = Tag.GetPageHtml; 

        for (int i = 0, j = myDataTable.Rows.Count; i < j; i++) 
        { 
            Tag.TagTable(new ExDataRow(myDataTable.Rows[i])); 
        } 
        TagBox.InnerHtml = Tag.GetHtml;

The method of processing page numbers to Session is not provided, and it is not a big deal. Calling the stored procedure returns The parameters and recording methods are similar to the batch data operation methods I wrote before. You only need to define an output method.

At present, I think these codes will still have flaws, and they will be strengthened during the code review later in the project. , what I want to say is don’t be confused by those things that are dragged around. That will never improve yourself. You must do something with an attitude of knowing what is happening and why. Only then will it help yourself. It will be obvious.

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