c# 读/写文件（各种格式）

最简单的:
 
--------写
 //content是要写入文本的字符串
 //(@txtPath + @"" + rid + ".txt");要被写入的TXT
  StreamWriter sw = new StreamWriter(@txtPath + @"" + rid + ".txt");
  sw.WriteLine(content);
  sw.Close();
 ---------读
 //folder被读取的文件路径
 text = File.ReadAllText(folder, System.Text.Encoding.GetEncoding("gb2312"));


 
-------写入流
             //将string写入文件    
             try
                 {
                     FileStream fs = new FileStream(@"d:数据处理法规20080116HTML" + Actid.ToString() + ".html", FileMode.OpenOrCreate, FileAccess.Write);
                     StreamWriter sw = new StreamWriter(fs,System.Text.Encoding.GetEncoding("gb2312"));
                     sw.Flush();
                     sw.BaseStream.Seek(0, SeekOrigin.Begin);
                     sw.Write(pageContent);
                     sw.Close();
                 }
                 catch (Exception ex) { }
 //HTTP向应后写出文件
 

HttpWebRequest myWebRequest = (HttpWebRequest)WebRequest.Create("http://www.microsoft.com");
 WebResponse result = null;
 try
 {
     myWebRequest = (HttpWebRequest)WebRequest.Create(Url);
     result = myWebRequest.GetResponse();
     Stream response = result.GetResponseStream();
     byte[] bytes = new byte[10240];
     int n = 1;
 
    FileStream fs = File.Create(@"d:数据处理法规20080116HTML" + Actid.ToString() + ".html");
     while (n > 0)
     {
         n = response.Read(bytes, 0, 10240);
         fs.Write(bytes, 0, n);
     }
     response.Close();
     fs.Close();
 }
 catch (Exception ex) { }
 

//读取
 
string FileContent = File.ReadAllText(path, System.Text.Encoding.GetEncoding("gb2312"));