使用System.IO来读取以及修改文本文件

//1.读取html内容

string htmlUrl = @"new\new.html";

string htmlContent = string.Empty;

using (StreamReader reader = new StreamReader(htmlUrl))

{

       htmlContent += reader.ReadToEnd();

}

//2.修改html内容

string htmlContentNew = "新的html内容";

using (StreamWriter sw = new StreamWriter(url, false))

{

     sw.Write(htmlContentNew );

}

//3.修改XML文件

XmlDocument xmlDoc = new XmlDocument();

xmlDoc.Load(xmlpath);

//修改节点-增加或删除或其他操作

//修改后要保存到XML文件中

using (XmlTextWriter xmlWriter=new XmlTextWriter(xmlpath,Encoding.UTF8))

{

     xmlDoc.WriteTo(xmlWriter);

}