性能优化——生成静态页面（一）

在软件开发过程中有些页面是不经常变化的，此时如果重复从数据库中查询页面肯定会变慢，此时我们可以将该页面生成静态页面html的形式保存起来，下次加载的时候直接读取html页面

用流的形式读取页面生成静态页面，这种形式适用于静态化整个页面，下面用代码的形式记录学习的过程

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;

namespace ConsoleApplication1
{
    public abstract class ConvertPage
    {
        public bool flag;
        public string SavePath { set; get; }
        public string PagePath { set; get; }

        public abstract void PrintPage();
    }

    public class ConvertToHtml : ConvertPage
    {
        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="pageUrl"></param>
        /// <param name="saveUrl"></param>
        public ConvertToHtml(string pageUrl, string saveUrl)
        {
            if (string.IsNullOrEmpty(pageUrl) || string.IsNullOrEmpty(saveUrl))
                flag = false;

            base.PagePath = pageUrl;
            base.SavePath = saveUrl;
        }

        /// <summary>
        /// 获取文件保存的完整路径
        /// </summary>
        /// <returns></returns>
        public string GetFileSavePath()
        {
            var index = PagePath.LastIndexOf("/") + 1;
            var name = PagePath.Substring(index, PagePath.Length - index);
            if (!name.EndsWith(".html"))
                name = string.Format("{0}.html", name);
            return string.Format("{0}/{1}", SavePath, name);
        }

        /// <summary>
        /// 生成静态页面的方法
        /// </summary>
        public override void PrintPage()
        {
            if (flag == false)
                return;

            var filePath = GetFileSavePath();

            //设置重新生成静态页面的间隔时间
            if (File.Exists(filePath))
            {
                DateTime dt = File.GetLastWriteTime(filePath);
                TimeSpan ts = dt - DateTime.Now;
                if (ts.TotalHours < 1)
                    return;
            }
            else
            {
                FileStream file = File.Create(filePath);
                file.Close();
            }

            string Result;
            WebRequest MyRequest = System.Net.HttpWebRequest.Create(PagePath);
            WebResponse MyResponse = MyRequest.GetResponse();
            using (StreamReader MyReader = new StreamReader(MyResponse.GetResponseStream(), System.Text.Encoding.GetEncoding("utf-8")))//这里根据网站的编码格式而定  
            {
                Result = MyReader.ReadToEnd();
                MyReader.Close();
            }

            FileStream fs = new FileStream(filePath, FileMode.Append, FileAccess.Write);
            StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.GetEncoding("utf-8"));
            sw.WriteLine(Result);
            sw.Close();
            fs.Close();


        }
    }
}

 调用方式：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            ConvertPage convert = new ConvertToHtml("http://www.linkin.net/job", @"D:	est");
            convert.PrintPage();
        }
    }
}

另外当需要读取页面内容时分为读取本地页面和读取线上页面

读取本地页面：

//FilePath为你的test.html的文件路径  
public static string WriteFile(string FilePath)
    {
        Encoding code = Encoding.GetEncoding("utf-8");
        // 读取模板文件   
        string temp = HttpContext.Current.Server.MapPath(FilePath);
        string str = "";
        StreamReader sr = null;
        try
        {
            sr = new StreamReader(temp, code);
            str = sr.ReadToEnd(); // 读取文件  
        }
        catch (Exception exp)
        {
            HttpContext.Current.Response.Write(exp.Message);
            HttpContext.Current.Response.End();
            sr.Close();
        }
        finally
        {
            sr.Close();
        }
        return str;
    }

 读取线上动态页面：

   /// <summary>
        /// 读取动态页面HTML
        /// </summary>
        /// <param name="strUrl">动态页面地址</param>
        /// <returns></returns>
        public static string GetStringByUrl(string dynamicUrl)
        {
            WebRequest wrt = null;
            WebResponse wrse = null;

            try
            {
                wrt = WebRequest.Create(dynamicUrl);
                
                wrt.Timeout = 8000;
                wrse = wrt.GetResponse();

                HttpWebResponse res = (HttpWebResponse)wrse;
                if (res.StatusCode == HttpStatusCode.OK)
                { 
                    
                }
                else if (res.StatusCode == HttpStatusCode.Redirect)
                {
                    var redURL = res.ResponseUri.AbsoluteUri;
                }

                Stream strM = null;
                StreamReader SR = null;

                try
                {
                    strM = wrse.GetResponseStream();
                    SR = new StreamReader(strM, code);

                    string strallstrm = SR.ReadToEnd();
                    return strallstrm;
                }
                catch (Exception ex)
                { }
                finally
                {
                    if (SR != null)
                    {
                        try
                        {
                            SR.Dispose(); SR.Close();
                        }
                        finally { SR = null; }
                    }
                    if (strM != null)
                    {
                        try { strM.Dispose(); strM.Close(); }
                        finally { strM = null; }
                    }
                }

                return string.Empty;
            }
            catch
            {
                return "";
            }
            finally
            {
                if (wrse != null)
                {
                    try { wrse.Close();}
                    finally { wrse = null; }
                }
                if (wrt != null)
                    wrt = null;
            }
        }