参考:
http://www.cnblogs.com/zxx193/p/3605238.html?utm_source=tuicool
http://www.cnblogs.com/freeliver54/p/3430956.html
http://www.cnblogs.com/simhare/archive/2007/07/18/821938.html
定义string变量为str,内存流变量为ms,比特数组为bt
1.字符串=>比特数组
(1)byte[] bt=System.Text.Encoding.Default.GetBytes("字符串");
(2)byte[] bt=Convert.FromBase64String("字符串");
补充:
System.Text.Encoding.Unicode.GetBytes(str);
System.Text.Encoding.UTF8.GetBytes(str);
System.Text.Encoding.GetEncoding("gb2312").GetBytes(str); //指定编码方式
string str = "中国?ss123?";
byte[] bytes = System.Text.Encoding.Default.GetBytes(str); //gb2312编码 汉字占2个字节、英文字母占1个字节 bytes长度为12
string s = System.Text.Encoding.Default.GetString(new byte[] { bytes[0],bytes[1] });//解码后为“中”
byte[] bytes = {97, 98, 99, 100, 101, 102};
string str = System.Text.Encoding.ASCII.GetString(bytes); //结果为:abcdef ASCII码表
2.比特数组=>字符串
(1)string str=System.Text.Encoding.Default.GetString(bt);
(2)string str=Convert.ToBase64String(bt);
3.字符串=>流
(1)MemoryStream ms=new MemoryStream(System.Text.Encoding.Default.GetBytes("字符串"));
(2)MemoryStream ms=new MemoryStream(Convert.FromBase64String("字符串"));
4.流=>字符串
(1)string str=Convert.ToBase64String(ms.ToArray());
(2)string str=System.Text.Encoding.Default.GetString(ms.ToArray());
5.比特数组=>流
(1)MemoryStream ms=new MemoryStream(bt);
(2)MemoryStream ms=new MemoryStream();ms.Read(bt,0,bt.Lenght);
6.流=>比特数组
(1)byte[] bt=ms.ToArray();
(2)MemoryStream ms=new MemoryStream();ms.Write(bt,0,ms.Length);
7、byte[]与base64string的互相转换
在C#中
图片到byte[]再到base64string的转换:
Bitmap bmp = new Bitmap(filepath);
MemoryStream ms = new MemoryStream();
bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
byte[] arr = new byte[ms.Length];
ms.Position = 0;
ms.Read(arr, 0, (int)ms.Length);
ms.Close();
string pic = Convert.ToBase64String(arr);
base64string到byte[]再到图片的转换:
byte[] imageBytes = Convert.FromBase64String(pic);
//读入MemoryStream对象
MemoryStream memoryStream = new MemoryStream(imageBytes, 0, imageBytes.Length);
memoryStream.Write(imageBytes, 0, imageBytes.Length);
//转成图片
Image image = Image.FromStream(memoryStream);
现在的数据库开发中:图片的存放方式一般有CLOB:存放base64string
BLOB:存放byte[]
一般推荐使用byte[]。因为图片可以直接转换为byte[]存放到数据库中
若使用base64string 还需要从byte[]转换成base64string 。更浪费性能。
8、C# byte数组与Image的相互转换