以前在網(wǎng)上找到了很多關(guān)于中文驗(yàn)證碼的文章（園子里也有，大家自己去找吧），但是都沒有調(diào)測(cè)成功，總出現(xiàn)
The target '__Page' for the callback could not be found or did not implement ICallbackEventHandler不能ICallbackEventHandler回掉的錯(cuò)誤，我進(jìn)行了一下修正并整理，現(xiàn)在可以實(shí)現(xiàn)了中文驗(yàn)證碼無刷新的操作，現(xiàn)特把全部源碼分享給大家
核心源碼
1
public partial class Image : System.Web.UI.Page
2
{
3
protected void Page_Load(object sender, EventArgs e)
4
{
5 CreateCheckCodeImage(GenCode(4));
6
}
7 /**//**//**//// <summary>
8 /// '產(chǎn)生隨機(jī)字符串
9 /// </summary>
10 /// <param name="num">隨機(jī)出幾個(gè)字符</param>
11 /// <returns>隨機(jī)出的字符串</returns>
12 private string GenCode(int num)
13 {
14 string str = "的一是在不了有和人這中大為上個(gè)國我以要他時(shí)來用們...";
15 char[] chastr = str.ToCharArray();
16
17 string code = "";
18 Random rd = new Random();
19 int i;
20 for (i = 0; i < num; i++)
21 {
22 //code += source[rd.Next(0, source.Length)];
23 code += str.Substring(rd.Next(0, str.Length), 1);
24 }
25 return code;
26
27 }
28
29 /**//**//**//// <summary>
30 /// 生成圖片（增加背景噪音線、前景噪音點(diǎn)）
31 /// </summary>
32 /// <param name="checkCode">隨機(jī)出字符串</param>
33 private void CreateCheckCodeImage(string checkCode)
34 {
35 if (checkCode.Trim() == "" || checkCode == null)
36 return;
37 Session["Code"] = checkCode; //將字符串保存到Session中，以便需要時(shí)進(jìn)行驗(yàn)證
38 System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)(checkCode.Length * 21.5), 22);
39 Graphics g = Graphics.FromImage(image);
40 try
41 {
42 //生成隨機(jī)生成器
43 Random random = new Random();
44
45 //清空?qǐng)D片背景色
46 g.Clear(Color.White);
47
48 // 畫圖片的背景噪音線
49 int i;
50 for (i = 0; i < 25; i++)
51 {
52 int x1 = random.Next(image.Width);
53 int x2 = random.Next(image.Width);
54 int y1 = random.Next(image.Height);
55 int y2 = random.Next(image.Height);
56 g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
57 }
58
59 Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold));
60 System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2F, true);
61 g.DrawString(checkCode, font, brush, 2, 2);
62
63 //畫圖片的前景噪音點(diǎn)
64 g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
65 System.IO.MemoryStream ms = new System.IO.MemoryStream();
66 image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
67 Response.ClearContent();
68 Response.ContentType = "image/Gif";
69 Response.BinaryWrite(ms.ToArray());
70
71 }
72 catch
73 {
74 g.Dispose();
75 image.Dispose();
76 }
77
78 }
希望該源碼只是一個(gè)拋磚引玉的作用，你可以進(jìn)行修改，比如說改中文字庫，字體背景噪音等等
默認(rèn)帳號(hào)密碼均為51aspx，這里用戶登錄只是一個(gè)驗(yàn)證的例子，沒有其他功能
作者51aspx
完整源碼下載地址http://www.51aspx.com/CV/ZhongWenYanZhengMa
