Jpg文件和Xml 文件格式的互换

  // 把Jpg文件保存为Xml文件
             /**/ /*--------------------------------------------*/             
             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("e://C#.pdf",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("e://docSave.xml"); 
                MessageBox.Show("读写结束！");
            }
             catch  (Exception ex)
             {
                MessageBox.Show(ex.ToString());

            }         
             /**/ /*--------------------------------------------*/

// 把XML文件保存为Jpg文件
             /**/ /*--------------------------------------------*/
             try
             {
                int readByte = 0;
                int bytesToRead = 1044;
                XmlTextReader xmlTxtRd = new XmlTextReader("e://docSave.xml");
                FileStream fs = new FileStream("e://002.pdf",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();
                MessageBox.Show("读写结束！");
            }
             catch  (Exception ex)
             {
                MessageBox.Show(ex.ToString());
            }
             /**/ /*--------------------------------------------*/

转换内容 不仅仅限于Jpg  

 

图片转换，把bmp图片转换为jpg图片

using  System.IO;
using  System.Drawing.Imaging;

public   class  imgConvert
{
        private void BMPToJPG(string bmpFileName,string jpgFileName)
        {
                        
            
            System.Drawing.Image img;
            img=ReturnPhoto(bmpFileName);
    
            img.Save(jpgFileName,ImageFormat.Jpeg);
        }

        private Image ReturnPhoto(string bmpFileName)
        {
            System.IO.FileStream stream ;
            stream=File.OpenRead(bmpFileName);
            Bitmap bmp = new Bitmap(stream);
            System.Drawing.Image image = bmp;//得到原图
            //创建指定大小的图
            System.Drawing.Image newImage = image.GetThumbnailImage(bmp.Width, bmp.Height, null, new IntPtr());
            Graphics g=Graphics.FromImage(newImage);
            g.DrawImage(newImage,0,0, newImage.Width, newImage.Height); //将原图画到指定的图上
            g.Dispose();
            stream.Close();
            return newImage;
        }
}