读写文件

   public static void XmlSave()
        {
            try
            {
                XmlDocument myXmlDoc = new XmlDocument();
                myXmlDoc.LoadXml("<picture><name>picture</name></picture>");

                XmlElement elem = myXmlDoc.CreateElement("image");

                // 打开图片文件，利用该图片构造一个文件流
                FileStream fs = new FileStream("http://www.cnblogs.com/1.jpg",FileMode.Open);
                // 使用文件流构造一个二进制读取器将基元数据读作二进制值
                BinaryReader br = new BinaryReader(fs);

                byte[] imageBuffer = new byte[br.BaseStream.Length];

                br.Read(imageBuffer,0,Convert.ToInt32(br.BaseStream.Length));

                string textString = System.Convert.ToBase64String(imageBuffer);

                fs.Close();
                br.Close();

                XmlText text = myXmlDoc.CreateTextNode(textString);

                myXmlDoc.DocumentElement.AppendChild(elem);
                myXmlDoc.DocumentElement.LastChild.AppendChild(text);

                myXmlDoc.Save("http://www.cnblogs.com/docSave.xml");
                Console.WriteLine("over");
           }
           catch(Exception ex)
           {
             Console.WriteLine(ex.ToString());
           }

        }
        public static void xmlRead()
        {
            try
            {
                int readByte = 0;
                int bytesToRead = 1044;
                XmlTextReader xmlTxtRd = new XmlTextReader("http://www.cnblogs.com/docSave.xml");
                FileStream fs = new FileStream("http://www.cnblogs.com/002.jpg", FileMode.Create);
                BinaryWriter bw = new BinaryWriter(fs);

                byte[] base64buffer = new byte[bytesToRead];
                while (xmlTxtRd.Read())
                {
                    if (xmlTxtRd.NodeType == XmlNodeType.Element && xmlTxtRd.Name == "image")
                    {
                        do
                        {
                            readByte = xmlTxtRd.ReadBase64(base64buffer, 0, bytesToRead);
                            bw.Write(base64buffer, 0, readByte);
                        }
                        while (bytesToRead <= readByte);
                    }
                }

                bw.Flush();
                bw.Close();
                fs.Close();

                xmlTxtRd.Close();
                Console.WriteLine("over");
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }

        }