页面:
1 <html xmlns="http://www.w3.org/1999/xhtml">
2 <head runat="server">
3 <title>验证码</title>
4 <script type="text/javascript">
5 //换一张
6 function change() {
7 var img = document.getElementById("ValidateCode");
8 img.src = img.src + ‘?‘;
9 }
10 </script>
11 </head>
12 <body>
13 <form id="form1" runat="server">
14 <div>
15 <table>
16 <tr>
17 <th>
18 验证码
19 </th>
20 <td>
21 <asp:TextBox runat="server" ID="tbCheckCode" CssClass="Small" MaxLength="4"></asp:TextBox>
22 </td>
23 <td>
24 <img src="VerifyCode.aspx" id="ValidateCode" alt="换一张" onclick="javascript:change()" />
25 </td>
26 <td>
27 <a id="ChangeCode" href="#" onclick="javascript:change()">换一张</a>
28 </td>
29 </tr>
30 <tr>
31 <td>
32 <asp:Button runat="server" ID="LoginSubmit" OnClick="LoginSubmits" Text="登录" />
33 </td>
34 </tr>
35 </table>
36 </div>
37 </form>
38 </body>
39 </html>
后台代码:
1 /// <summary>
2 /// 登录
3 /// </summary>
4 /// <param name="sender"></param>
5 protected void LoginSubmits(object sender, EventArgs e)
6 {
7 CheckLogin();
8 }
9
10 #region 私有方法
11 #region
12 public static Boolean IsNotNull(Object str)
13 {
14 return !IsNull(str);
15 }
16 public static Boolean IsNull(Object str)
17 {
18 return str == null;
19 }
20 public static void Show(System.Web.UI.Page page, string msg)
21 {
22 page.ClientScript.RegisterStartupScript(page.GetType(), "message",
23 "<script language=‘javascript‘ defer>alert(‘" + msg.ToString() + "‘);</script>");
24 }
25 #endregion
26
27 private void CheckLogin()
28 {
29 if (tbCheckCode.Text.Trim() == "")
30 {
31 Show(this, "验证码不能为空!");
32 return;
33 }
34 else
35 {
36 if (IsNotNull(Session["ValidateCheckCode"]))
37 {
38 if (tbCheckCode.Text.Trim() != Session["ValidateCheckCode"].ToString())
39 {
40 Show(this, "验证码填写不正确!");
41 tbCheckCode.Text = "";
42 return;
43 }
44 }
45 else
46 {
47 Show(this, "请刷新验证码！");
48 return;
49 }
50 }
51 }
52 #endregion
53 }
54 }
生成验证码:
1 using System;
2 using System.Drawing;
3 using System.Text;
4 using System.Web;
5
6 namespace Web.TEXT
7 {
8 public partial class VerifyCode : System.Web.UI.Page
9 {
10 public Encoding GB = Encoding.GetEncoding("GB2312");
11
12 protected void Page_Load(object sender, EventArgs e)
13 {
14 VerifyCode v = new VerifyCode();
15
16 v.Length = this.length;
17 v.FontSize = this.fontSize;
18 v.Chaos = this.chaos;
19 v.BackgroundColor = this.backgroundColor;
20 v.ChaosColor = this.chaosColor;
21 v.CodeSerial = this.codeSerial;
22 v.Colors = this.colors;
23 v.Fonts = this.fonts;
24 v.Padding = this.padding;
25 string code = v.CreateVerifyCode(); //取随机码
26 v.CreateImageOnPage(code, this.Context); // 输出图片
27 Response.Cookies.Add(new HttpCookie("CheckCode", code.ToUpper())); // 使用Cookies取验证码的值
28
29 System.Web.HttpContext.Current.Session["ValidateCheckCode"] = code;
30 //return checkCode;
31 }
32
33 #region 验证码长度(默认4个验证码的长度)
34
35 private int length = 4;
36
37 public int Length
38 {
39 get { return length; }
40 set { length = value; }
41 }
42
43 #endregion
44
45 #region 验证码字体大小(为了显示扭曲效果，默认40像素，可以自行修改)
46
47 private int fontSize = 12;
48
49 public int FontSize
50 {
51 get { return fontSize; }
52 set { fontSize = value; }
53 }
54
55 #endregion
56
57 #region 边框补(默认1像素)
58
59 private int padding = 1;
60
61 public int Padding
62 {
63 get { return padding; }
64 set { padding = value; }
65 }
66
67 #endregion
68
69 #region 是否输出燥点(默认不输出)
70
71 private bool chaos = true;
72
73 public bool Chaos
74 {
75 get { return chaos; }
76 set { chaos = value; }
77 }
78
79 #endregion
80
81 #region 输出燥点的颜色(默认灰色)
82
83 private Color chaosColor = Color.LightGray;
84
85 public Color ChaosColor
86 {
87 get { return chaosColor; }
88 set { chaosColor = value; }
89 }
90
91 #endregion
92
93 #region 自定义背景色(默认白色)
94
95 private Color backgroundColor = Color.White;
96
97 public Color BackgroundColor
98 {
99 get { return backgroundColor; }
100 set { backgroundColor = value; }
101 }
102
103 #endregion
104
105 #region 自定义随机颜色数组
106
107 private Color[] colors =
108 {
109 Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown,
110 Color.DarkCyan, Color.Purple
111 };
112
113 public Color[] Colors
114 {
115 get { return colors; }
116 set { colors = value; }
117 }
118
119 #endregion
120
121 #region 自定义字体数组
122
123 private string[] fonts = {"Arial", "Georgia"};
124
125 public string[] Fonts
126 {
127 get { return fonts; }
128 set { fonts = value; }
129 }
130
131 #endregion
132
133 #region 自定义随机码字符串序列(使用逗号分隔)
134
135 private string codeSerial = "0,1,2,3,4,5,6,7,8,9";
136 // string codeSerial = "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
137 // string codeSerial = "殃,央,鸯,秧,杨,扬,佯,疡,羊,洋,阳,氧,仰,痒,养,样,漾,邀,腰,妖,瑶,摇,尧,遥,窑,谣,姚,咬,舀,药,要,耀,椰,噎,耶,爷,野,冶,也,页,掖,业,叶,曳,腋,夜,液,一,壹,医,揖,铱,依,伊,衣,颐,夷,遗,移,仪,胰,疑,沂,宜,姨,彝,椅,蚁,倚,已,乙,矣,以,艺,抑,易,邑,屹,亿,役,臆,逸,肄,疫,亦,裔,意,毅,忆,义,益,溢,诣,议,谊,译,异,翼,翌,绎,茵,荫,因,殷,音,阴,姻,吟,银,淫,寅,饮,尹,引,隐,印,英,樱,婴,鹰,应,缨,莹,萤,营,荧,蝇,迎,赢,盈,影,颖,硬,映,哟,拥,佣,臃,痈,庸,雍,踊,蛹,咏,泳,涌,永,恿,勇,用,幽,优,悠,忧,尤,由,邮,铀,犹,油,游,酉,有,友,右,佑,釉,诱,又,幼,迂,淤,于,盂,榆,虞,愚,舆,余,俞,逾,鱼,愉,渝,渔,隅,予,娱,雨,与,屿,禹,株,蛛,朱,猪,诸,诛,逐,竹,烛,煮,拄,瞩,嘱,主,著,柱,助,蛀,贮,铸,筑,住,注,祝,驻,抓,爪,拽,专,砖,转,撰,赚,篆,桩,庄,装,妆,撞,壮,状,椎,锥,追,赘,坠,缀,谆,准,捉,拙,卓,桌,琢,茁,酌,啄,着,灼,浊,兹,咨,资,姿,滋,淄,孜,紫,仔,籽,滓,子,自,渍,字,鬃,棕,踪,宗,综,总,纵,邹,走,奏,揍,租,足,卒,族,祖,诅,阻,组,钻,纂,嘴,醉,最,罪,尊,遵,昨,左,佐,柞,做,作,坐,座";
138 public string CodeSerial
139 {
140 get { return codeSerial; }
141 set { codeSerial = value; }
142 }
143
144 #endregion
145
146 //产生波形滤镜效果
147
148 #region 产生波形滤镜效果
149
150 private const double PI = 3.1415926535897932384626433832795;
151 private const double PI2 = 6.283185307179586476925286766559;
152
153 /**/
154
155 /// <summary>
156 /// 正弦曲线Wave扭曲图片（Edit By 51aspx.com）
157 /// </summary>
158 /// <param name="srcBmp">图片路径</param>
159 /// <param name="bXDir">如果扭曲则选择为True</param>
160 /// <param name="nMultValue">波形的幅度倍数，越大扭曲的程度越高，一般为3</param>
161 /// <param name="dPhase">波形的起始相位，取值区间[0-2*PI)</param>
162 /// <returns></returns>
163 public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)
164 {
165 System.Drawing.Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height);
166
167 // 将位图背景填充为白色
168 System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage(destBmp);
169 graph.FillRectangle(new SolidBrush(System.Drawing.Color.White), 0, 0, destBmp.Width, destBmp.Height);
170 graph.Dispose();
171
172 double dBaseAxisLen = bXDir ? (double) destBmp.Height : (double) destBmp.Width;
173
174 for (int i = 0; i < destBmp.Width; i++)
175 {
176 for (int j = 0; j < destBmp.Height; j++)
177 {
178 double dx = 0;
179 dx = bXDir ? (PI2*(double) j)/dBaseAxisLen : (PI2*(double) i)/dBaseAxisLen;
180 dx += dPhase;
181 double dy = Math.Sin(dx);
182
183 // 取得当前点的颜色
184 int nOldX = 0, nOldY = 0;
185 nOldX = bXDir ? i + (int) (dy*dMultValue) : i;
186 nOldY = bXDir ? j : j + (int) (dy*dMultValue);
187
188 System.Drawing.Color color = srcBmp.GetPixel(i, j);
189 if (nOldX >= 0 && nOldX < destBmp.Width
190 && nOldY >= 0 && nOldY < destBmp.Height)
191 {
192 destBmp.SetPixel(nOldX, nOldY, color);
193 }
194 }
195 }
196
197 return destBmp;
198 }
199
200
201
202 #endregion
203
204 #region 生成校验码图片
205
206 public Bitmap CreateImageCode(string code)
207 {
208 int fSize = FontSize;
209 int fWidth = fSize + Padding;
210
211 int imageWidth = (int) (code.Length*fWidth) + 4 + Padding*2;
212 int imageHeight = fSize*2 + Padding;
213
214 System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth, imageHeight);
215
216 Graphics g = Graphics.FromImage(image);
217
218 g.Clear(BackgroundColor);
219
220 Random rand = new Random();
221
222 //给背景添加随机生成的燥点
223 if (this.Chaos)
224 {
225
226 Pen pen = new Pen(ChaosColor, 0);
227 int c = Length*10;
228
229 for (int i = 0; i < c; i++)
230 {
231 int x = rand.Next(image.Width);
232 int y = rand.Next(image.Height);
233
234 g.DrawRectangle(pen, x, y, 1, 1);
235 }
236 }
237
238 int left = 0, top = 0, top1 = 1, top2 = 1;
239
240 int n1 = (imageHeight - FontSize - Padding*2);
241 int n2 = n1/4;
242 top1 = n2;
243 top2 = n2*2;
244
245 Font f;
246 Brush b;
247
248 int cindex, findex;
249
250 #region 随机字体和颜色的验证码字符
251
252 for (int i = 0; i < code.Length; i++)
253 {
254 cindex = rand.Next(Colors.Length - 1);
255 findex = rand.Next(Fonts.Length - 1);
256
257 f = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold);
258 b = new System.Drawing.SolidBrush(Colors[cindex]);
259
260 if (i%2 == 1)
261 {
262 top = top2;
263 }
264 else
265 {
266 top = top1;
267 }
268
269 left = i*fWidth;
270
271 g.DrawString(code.Substring(i, 1), f, b, left, top);
272 }
273
274 //画一个边框 边框颜色为Color.Gainsboro
275 g.DrawRectangle(new Pen(Color.Gainsboro, 0), 0, 0, image.Width - 1, image.Height - 1);
276 g.Dispose();
277
278 //产生波形
279 //image = TwistImage(image, true, 8, 4);
280
281 return image;
282 }
283
284 #endregion
285
286 //将创建好的图片输出到页面
287 public void CreateImageOnPage(string code, HttpContext context)
288 {
289 System.IO.MemoryStream ms = new System.IO.MemoryStream();
290 Bitmap image = this.CreateImageCode(code);
291
292 image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
293
294 context.Response.ClearContent();
295 context.Response.ContentType = "image/Jpeg";
296 context.Response.BinaryWrite(ms.GetBuffer());
297
298 ms.Close();
299 ms = null;
300 image.Dispose();
301 image = null;
302 }
303
304 #endregion
305
306 #region 生成随机字符码
307
308 public string CreateVerifyCode(int codeLen)
309 {
310 if (codeLen == 0)
311 {
312 codeLen = Length;
313 }
314
315 string[] arr = CodeSerial.Split(‘,‘);
316
317 string code = "";
318
319 int randValue = -1;
320
321 Random rand = new Random(unchecked((int) DateTime.Now.Ticks));
322
323 for (int i = 0; i < codeLen; i++)
324 {
325 randValue = rand.Next(0, arr.Length - 1);
326
327 code += arr[randValue];
328 }
329
330 return code;
331 }
332
333 public string CreateVerifyCode()
334 {
335 return CreateVerifyCode(0);
336 }
337
338 #endregion
339 }
340 }
效果:
时间： 2024-04-19 21:41:21