c# 圖片 與 BASE64 字元串 互相轉換。

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Drawing;
 4 using System.IO;
 5 using System.Linq;
 6 using System.Web;
 7 using System.Drawing.Imaging;
 8 // 博客園  aC#Coder 整理
 9 namespace Html5Image.Tools
10 {
11     public class ImageTool
12     {
13         //圖片 轉為    base64編碼的文本
14         public static string ImgToBase64String(Bitmap bmp)
15         {
16             //Bitmap bmp = new Bitmap(Imagefilename);
17             //this.pictureBox1.Image = bmp;
18             //FileStream fs = new FileStream(Imagefilename + ".txt", FileMode.Create);
19             //StreamWriter sw = new StreamWriter(fs);
20 
21             MemoryStream ms = new MemoryStream();
22             bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
23             byte[] arr = new byte[ms.Length];
24             ms.Position = 0;
25             ms.Read(arr, 0, (int)ms.Length);
26             ms.Close();
27             String strbaser64 = Convert.ToBase64String(arr);
28 
29             return strbaser64;
30         }
31 
32         public static Bitmap Base64StringToImage(string base64Img)
33         {
34             byte[] bytes = Convert.FromBase64String(base64Img);
35             MemoryStream ms = new MemoryStream();
36             ms.Write(bytes, 0, bytes.Length);
37             Bitmap bmp = new Bitmap(ms);
38 
39             return bmp;
40         }
41 
42         /// <summary>
43         /// 保存圖片
44         /// </summary>
45         /// <param name="base64Img"></param>
46         /// <param name="imgPath"></param>
47         /// <param name="imgFormat">EX: System.Drawing.Imaging.Jpeg </param>
48         public static void SaveFile(string base64Img, string imgPath, ImageFormat imgFormat )
49         {
50             string dir = Path.GetDirectoryName(imgPath);
51             if (!Directory.Exists(dir))
52             {
53                 Directory.CreateDirectory(dir);
54             }
55             var bitmap = Base64StringToImage(base64Img); 
56             bitmap.Save(imgPath, imgFormat); 
57         }
58     }
59 }