先给大家看看效果图：
页面代码：
<html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>验证码</title> <script type="text/javascript"> //换一张 function change() { var img = document.getElementById("ValidateCode"); img.src = img.src + '?'; } </script> </head> <body> <form runat="server"> <div> <table> <tr> <th> 验证码 </th> <td> <asp:TextBox runat="server" CssClass="Small" MaxLength="4"></asp:TextBox> </td> <td> <img src="https://www.jb51.net/VerifyCode.aspx" alt="换一张" /> </td> <td> <a href="#">换一张</a> </td> </tr> <tr> <td> <asp:Button runat="server" Text="登录" /> </td> </tr> </table> </div> </form> </body> </html>
后台代码:
/// <summary> /// 登录 /// </summary> /// <param></param> protected void LoginSubmits(object sender, EventArgs e) { CheckLogin(); } #region 私有方法 #region public static Boolean IsNotNull(Object str) { return !IsNull(str); } public static Boolean IsNull(Object str) { return str == null; } public static void Show(System.Web.UI.Page page, string msg) { page.ClientScript.RegisterStartupScript(page.GetType(), "message", "<script language='javascript' defer>alert('" + msg.ToString() + "');</script>"); } #endregion private void CheckLogin() { if (tbCheckCode.Text.Trim() == "") { Show(this, "验证码不能为空!"); return; } else { if (IsNotNull(Session["ValidateCheckCode"])) { if (tbCheckCode.Text.Trim() != Session["ValidateCheckCode"].ToString()) { Show(this, "验证码填写不正确!"); tbCheckCode.Text = ""; return; } } else { Show(this, "请刷新验证码！"); return; } } } #endregion } }
生成验证码:
using System; using System.Drawing; using System.Text; using System.Web; namespace Web.TEXT { public partial class VerifyCode : System.Web.UI.Page { public Encoding GB = Encoding.GetEncoding("GB2312"); protected void Page_Load(object sender, EventArgs e) { VerifyCode v = new VerifyCode(); v.Length = this.length; v.FontSize = this.fontSize; v.Chaos = this.chaos; v.BackgroundColor = this.backgroundColor; v.ChaosColor = this.chaosColor; v.CodeSerial = this.codeSerial; v.Colors = this.colors; v.Fonts = this.fonts; v.Padding = this.padding; string code = v.CreateVerifyCode(); //取随机码 v.CreateImageOnPage(code, this.Context); // 输出图片 Response.Cookies.Add(new HttpCookie("CheckCode", code.ToUpper())); // 使用Cookies取验证码的值 System.Web.HttpContext.Current.Session["ValidateCheckCode"] = code; //return checkCode; } #region 验证码长度(默认4个验证码的长度) private int length = 4; public int Length { get { return length; } set { length = value; } } #endregion #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) private int fontSize = 12; public int FontSize { get { return fontSize; } set { fontSize = value; } } #endregion #region 边框补(默认1像素) private int padding = 1; public int Padding { get { return padding; } set { padding = value; } } #endregion #region 是否输出燥点(默认不输出) private bool chaos = true; public bool Chaos { get { return chaos; } set { chaos = value; } } #endregion #region 输出燥点的颜色(默认灰色) private Color chaosColor = Color.LightGray; public Color ChaosColor { get { return chaosColor; } set { chaosColor = value; } } #endregion #region 自定义背景色(默认白色) private Color backgroundColor = Color.White; public Color BackgroundColor { get { return backgroundColor; } set { backgroundColor = value; } } #endregion #region 自定义随机颜色数组 private Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple }; public Color[] Colors { get { return colors; } set { colors = value; } } #endregion #region 自定义字体数组 private string[] fonts = {"Arial", "Georgia"}; public string[] Fonts { get { return fonts; } set { fonts = value; } } #endregion #region 自定义随机码字符串序列(使用逗号分隔) private string codeSerial = "0,1,2,3,4,5,6,7,8,9"; // 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"; // 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"; public string CodeSerial { get { return codeSerial; } set { codeSerial = value; } } #endregion //产生波形滤镜效果 #region 产生波形滤镜效果 private const double PI = 3.1415926535897932384626433832795; private const double PI2 = 6.283185307179586476925286766559; /**/ /// <summary> /// 正弦曲线Wave扭曲图片（Edit By 51aspx.com） /// </summary> /// <param>图片路径</param> /// <param>如果扭曲则选择为True</param> /// <param>波形的幅度倍数，越大扭曲的程度越高，一般为3</param> /// <param>波形的起始相位，取值区间[0-2*PI)</param> /// <returns></returns> public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase) { System.Drawing.Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height); // 将位图背景填充为白色 System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage(destBmp); graph.FillRectangle(new SolidBrush(System.Drawing.Color.White), 0, 0, destBmp.Width, destBmp.Height); graph.Dispose(); double dBaseAxisLen = bXDir ? (double) destBmp.Height : (double) destBmp.Width; for (int i = 0; i < destBmp.Width; i++) { for (int j = 0; j < destBmp.Height; j++) { double dx = 0; dx = bXDir ? (PI2*(double) j)/dBaseAxisLen : (PI2*(double) i)/dBaseAxisLen; dx += dPhase; double dy = Math.Sin(dx); // 取得当前点的颜色 int nOldX = 0, nOldY = 0; nOldX = bXDir ? i + (int) (dy*dMultValue) : i; nOldY = bXDir ? j : j + (int) (dy*dMultValue); System.Drawing.Color color = srcBmp.GetPixel(i, j); if (nOldX >= 0 && nOldX < destBmp.Width && nOldY >= 0 && nOldY < destBmp.Height) { destBmp.SetPixel(nOldX, nOldY, color); } } } return destBmp; } #endregion #region 生成校验码图片 public Bitmap CreateImageCode(string code) { int fSize = FontSize; int fWidth = fSize + Padding; int imageWidth = (int) (code.Length*fWidth) + 4 + Padding*2; int imageHeight = fSize*2 + Padding; System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth, imageHeight); Graphics g = Graphics.FromImage(image); g.Clear(BackgroundColor); Random rand = new Random(); //给背景添加随机生成的燥点 if (this.Chaos) { Pen pen = new Pen(ChaosColor, 0); int c = Length*10; for (int i = 0; i < c; i++) { int x = rand.Next(image.Width); int y = rand.Next(image.Height); g.DrawRectangle(pen, x, y, 1, 1); } } int left = 0, top = 0, top1 = 1, top2 = 1; int n1 = (imageHeight - FontSize - Padding*2); int n2 = n1/4; top1 = n2; top2 = n2*2; Font f; Brush b; int cindex, findex; #region 随机字体和颜色的验证码字符 for (int i = 0; i < code.Length; i++) { cindex = rand.Next(Colors.Length - 1); findex = rand.Next(Fonts.Length - 1); f = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold); b = new System.Drawing.SolidBrush(Colors[cindex]); if (i%2 == 1) { top = top2; } else { top = top1; } left = i*fWidth; g.DrawString(code.Substring(i, 1), f, b, left, top); } //画一个边框 边框颜色为Color.Gainsboro g.DrawRectangle(new Pen(Color.Gainsboro, 0), 0, 0, image.Width - 1, image.Height - 1); g.Dispose(); //产生波形 //image = TwistImage(image, true, 8, 4); return image; } #endregion //将创建好的图片输出到页面 public void CreateImageOnPage(string code, HttpContext context) { System.IO.MemoryStream ms = new System.IO.MemoryStream(); Bitmap image = this.CreateImageCode(code); image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); context.Response.ClearContent(); context.Response.ContentType = "image/Jpeg"; context.Response.BinaryWrite(ms.GetBuffer()); ms.Close(); ms = null; image.Dispose(); image = null; } #endregion #region 生成随机字符码 public string CreateVerifyCode(int codeLen) { if (codeLen == 0) { codeLen = Length; } string[] arr = CodeSerial.Split(','); string code = ""; int randValue = -1; Random rand = new Random(unchecked((int) DateTime.Now.Ticks)); for (int i = 0; i < codeLen; i++) { randValue = rand.Next(0, arr.Length - 1); code += arr[randValue]; } return code; } public string CreateVerifyCode() { return CreateVerifyCode(0); } #endregion } }
是不是很有成就感，为大家分享的代码很完整，大家可以在这个基础进行扩展，希望大家喜欢。
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