例一：
在网站要目录下添加ValidateCode.aspx,路径自己定。
ValidateCode.aspx：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ValidateCode.aspx.cs" Inherits="ValidateCode_ValidateCode" %>
ValidateCode.aspx.cs：
using System; using System.Collections.Generic; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Drawing; using System.IO; using System.Drawing.Imaging; public partial class ValidateCode_ValidateCode : System.Web.UI.Page { private int letterWidth = 15;//单个字体的宽度范围 private int letterHeight = 27;//单个字体的高度范围 private int letterCount = 5;//验证码位数 private char[] chars = "23456789QWERTYUPASDFGHJKLZXCVBNMqwertyupasdfghjkzxcvbnm".ToCharArray(); private string[] fonts = { "Arial", "Georgia" }; /// <summary> /// 产生波形滤镜效果 /// </summary> private const double PI = 3.1415926535897932384626433832795; private const double PI2 = 6.283185307179586476925286766559; protected void Page_Load(object sender, EventArgs e) { //防止网页后退--禁止缓存 Response.Expires = 0; Response.Buffer = true; Response.ExpiresAbsolute = DateTime.Now.AddSeconds(-1); Response.AddHeader("pragma", "no-cache"); Response.CacheControl = "no-cache"; string str_ValidateCode = GetRandomNumberString(letterCount); HttpCookie objCookie = new HttpCookie("ValidateCode"); objCookie.Value = str_ValidateCode.ToLower(); objCookie.Path = "/"; objCookie.Expires = DateTime.Now.AddSeconds(1200); Response.Cookies.Add(objCookie); CreateImage(str_ValidateCode); } public void CreateImage(string checkCode) { int int_ImageWidth = checkCode.Length * letterWidth + 5; Random newRandom = new Random(); Bitmap image = new Bitmap(int_ImageWidth, letterHeight); Graphics g = Graphics.FromImage(image); //生成随机生成器 Random random = new Random(); //白色背景 g.Clear(Color.White); //画图片的背景噪音线 for (int i = 0; i < 10; i++) { int x1 = random.Next(image.Width); int x2 = random.Next(image.Width); int y1 = random.Next(image.Height); int y2 = random.Next(image.Height); g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2); } //画图片的前景噪音点 for (int i = 0; i < 10; i++) { int x = random.Next(image.Width); int y = random.Next(image.Height); image.SetPixel(x, y, Color.FromArgb(random.Next())); } //随机字体和颜色的验证码字符 int findex; for (int int_index = 0; int_index < checkCode.Length; int_index++) { findex = newRandom.Next(fonts.Length - 1); string str_char = checkCode.Substring(int_index, 1); Brush newBrush = new SolidBrush(GetRandomColor()); Point thePos = new Point(int_index * letterWidth + 1 + newRandom.Next(3), 1 + newRandom.Next(3));//5+1+a+s+p+x g.DrawString(str_char, new Font(fonts[findex], 14, FontStyle.Bold), newBrush, thePos); } //灰色边框 g.DrawRectangle(new Pen(Color.LightGray, 1), 0, 0, int_ImageWidth - 1, (letterHeight - 1)); //图片扭曲 //image = TwistImage(image, true, 3, 4); //将生成的图片发回客户端 MemoryStream ms = new MemoryStream(); image.Save(ms, ImageFormat.Png); Response.ClearContent(); //需要输出图象信息 要修改HTTP头 Response.ContentType = "image/Png"; Response.BinaryWrite(ms.ToArray()); g.Dispose(); image.Dispose(); } /// <summary> /// 正弦曲线Wave扭曲图片 /// </summary> /// <param name="srcBmp">图片路径</param> /// <param name="bXDir">如果扭曲则选择为True</param> /// <param name="nMultValue">波形的幅度倍数，越大扭曲的程度越高，一般为3</param> /// <param name="dPhase">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; } public Color GetRandomColor() { Random RandomNum_First = new Random((int)DateTime.Now.Ticks); System.Threading.Thread.Sleep(RandomNum_First.Next(50)); Random RandomNum_Sencond = new Random((int)DateTime.Now.Ticks); int int_Red = RandomNum_First.Next(210); int int_Green = RandomNum_Sencond.Next(180); int int_Blue = (int_Red + int_Green > 300) ? 0 : 400 - int_Red - int_Green; int_Blue = (int_Blue > 255) ? 255 : int_Blue; return Color.FromArgb(int_Red, int_Green, int_Blue); } // 生成随机数字字符串 public string GetRandomNumberString(int int_NumberLength) { Random random = new Random(); string validateCode = string.Empty; for (int i = 0; i < int_NumberLength; i++) validateCode += chars[random.Next(0, chars.Length)].ToString(); return validateCode; } }
使用时：
放在页面前
<span>验证码：</span>
<input name="txtCode" runat="server" type="text" id="txtCode" class="txtinput1" />
<img class="txtverity" onclick="this.src=this.src+'?'" src="ValidateCode/ValidateCode.aspx" style="cursor: pointer" alt="看不清楚，换一张" title="看不清楚，换一张" />
//onclick="this.src='ValifyCode.aspx?r=' + Math.random();
放在页面后
protected void btnSendMsg_Click(object sender, EventArgs e) {
if (Request.Cookies["ValidateCode"] == null) {
ScriptManager.RegisterStartupScript(this, GetType(), "msg", "alert('您的浏览器设置已被禁用 Cookies，您必须设置浏览器允许使用 Cookies 选项后才能使用本系统。')", true);
return;
}
else {
if (string.Compare(Request.Cookies["ValidateCode"].Value, txtCode.Value.Trim().ToLower(), true) == 0) {
insertMsgToUs();
}
else {
ScriptManager.RegisterStartupScript(this, GetType(), "msg", "alert('验证码不正确!')", true);
}
}
}
例二：
在网站根目录下添加自定义控件VerifyImage.ashx：
<%@ WebHandler Language="C#" Class="VerifyImage" %> using System; using System.Data; using System.Configuration; using System.Collections; using System.Collections.Generic; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; using System.Drawing; /// <summary> /// 生成验证码 /// </summary> public class VerifyImage : IHttpHandler { public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/plain"; VerifyImage v = new VerifyImage(); context.Response.Cache.SetCacheability(HttpCacheability.NoCache);//如不加，单击验证图片＇看不清换一张＇ 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, context); // 输出图片 context.Response.Cookies.Add(new HttpCookie("VerifyCode", code.ToUpper()));// 使用Cookies取验证码的值 } public bool IsReusable { get { return false; } } #region 验证码长度(默认6个验证码的长度) int length = 5; 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) int fontSize = 12; public int FontSize { get { return fontSize; } set { fontSize = value; } } #endregion #region 边框补(默认1像素) int padding = 2; public int Padding { get { return padding; } set { padding = value; } } #endregion #region 是否输出燥点(默认不输出) 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) 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) Color backgroundColor = Color.White; public Color BackgroundColor { get { return backgroundColor; } set { backgroundColor = value; } } #endregion #region 自定义随机颜色数组 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 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) string codeSerial = "1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,j,k,m,n,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,J,K,M,N,P,Q,R,S,T,U,V,W,X,Y,Z"; public string CodeSerial { get { return codeSerial; } set { codeSerial = value; } } #endregion #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 /// </summary> /// <param name="srcBmp">图片路径</param> /// <param name="bXDir">如果扭曲则选择为True</param> /// <param name="nMultValue">波形的幅度倍数，越大扭曲的程度越高，一般为3</param> /// <param name="dPhase">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; //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); image = TwistImage(image, true, 0, 0); return image; } #endregion #region 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 }
使用时：
放在页面前
<span>验证码：</span>
<input name="txtCode" runat="server" type="text" id="txtCode" class="txtinput1" />
<img src="VerifyImage.ashx" class="txtverity" onclick="this.src=this.src+'?'" alt="点击刷新验证码"/>
放在页面后
protected void btnSendMsg_Click(object sender, EventArgs e) {
if (Request.Cookies["VerifyCode"] == null) {
ScriptManager.RegisterStartupScript(this, GetType(), "msg", "alert('您的浏览器设置已被禁用 Cookies，您必须设置浏览器允许使用 Cookies 选项后才能使用本系统。')", true);
return;
}
else {
if (string.Compare(Request.Cookies["VerifyCode"].Value, txtCode.Value.Trim().ToUpper(), true) == 0) {
insertMsgToUs();
}
else {
ScriptManager.RegisterStartupScript(this, GetType(), "msg", "alert('验证码不正确!')", true);
}
}
}
例三：
添加ValidateCode.aspx，
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Drawing; using System.Drawing.Imaging; using System.IO; public partial class ValidateCode : System.Web.UI.Page { private void CreateImage(string checkCode) { int width = checkCode.Length * 14; Bitmap image = new Bitmap(width, 20); Graphics graphics = Graphics.FromImage(image); Font font = new Font("Arial ", 10f); Brush brush = new SolidBrush(Color.Black); Brush brush2 = new SolidBrush(Color.FromArgb(0xa6, 8, 8)); graphics.Clear(ColorTranslator.FromHtml("#99C1CB")); char[] chArray = checkCode.ToCharArray(); for (int i = 0; i < chArray.Length; i++) { if ((chArray[i] >= '0') && (chArray[i] <= '9')) { graphics.DrawString(chArray[i].ToString(), font, brush2, (float) (3 + (i * 12)), 3f); } else { graphics.DrawString(chArray[i].ToString(), font, brush, (float) (3 + (i * 12)), 3f); } } MemoryStream stream = new MemoryStream(); image.Save(stream, ImageFormat.Jpeg); base.Response.Cache.SetNoStore(); base.Response.ClearContent(); base.Response.ContentType = "image/Jpeg"; base.Response.BinaryWrite(stream.ToArray()); graphics.Dispose(); image.Dispose(); } private string CreateRandomCode(int codeCount) { string[] strArray = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,i,J,K,M,N,P,Q,R,S,T,U,W,X,Y,Z".Split(new char[] { ',' }); string str2 = ""; int num = -1; Random random = new Random(); for (int i = 0; i < codeCount; i++) { if (num != -1) { random = new Random((i * num) * ((int) DateTime.Now.Ticks)); } int index = random.Next(0x23); if (num == index) { return this.CreateRandomCode(codeCount); } num = index; str2 = str2 + strArray[index]; } return str2; } private string GetRandomCode(int CodeCount) { string[] strArray = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,i,J,K,M,N,P,Q,R,S,T,U,W,X,Y,Z".Split(new char[] { ',' }); string str2 = ""; int num = -1; Random random = new Random(); for (int i = 0; i < CodeCount; i++) { if (num != -1) { random = new Random((num * i) * ((int) DateTime.Now.Ticks)); } int index = random.Next(0x21); while (num == index) { index = random.Next(0x21); } num = index; str2 = str2 + strArray[index]; } return str2; } protected void Page_Load(object sender, EventArgs e) { string randomCode = this.GetRandomCode(4); this.Session["CheckCode"] = randomCode; this.SetPageNoCache(); this.CreateImage(randomCode); } private void SetPageNoCache() { base.Response.Buffer = true; base.Response.ExpiresAbsolute = DateTime.Now.AddSeconds(-1.0); base.Response.Expires = 0; base.Response.CacheControl = "no-cache"; base.Response.AppendHeader("Pragma", "No-Cache"); } }
页面前面：
<script type="text/javascript">
function newGuid() {
var guid = "";
for (var i = 1; i <= 32; i++) {
var n = Math.floor(Math.random() * 16.0).toString(16);
guid += n;
if ((i == 8) || (i == 12) || (i == 16) || (i == 20))
guid += "-";
}
return guid;
}
function ChangeCode() {
var myImg = document.getElementById("ImageCheck");
myImg.src = "ValidateCode.aspx?flag=" + newGuid();
return false;
}
</script>
<input name="CheckCode" class="txtinput1" runat="server" type="text" id="CheckCode"/>
<img id="ImageCheck" onclick="ChangeCode()" src="ValidateCode.aspx" alt="看不清楚，换一张" title="看不清楚，换一张" />
页面后面：
protected void btnSendMsg_Click(object sender, EventArgs e) {
if ((this.Session["CheckCode"] != null) && (this.Session["CheckCode"].ToString() != "")) {
if (this.Session["CheckCode"].ToString().ToLower() != this.CheckCode.Value.ToLower()) {
//this.lblMsg.Text = "验证码错误!";
ScriptManager.RegisterStartupScript(this, GetType(), "msg", "alert('验证码不正确!')", true);
this.Session["CheckCode"] = null;
return;
}
this.Session["CheckCode"] = null;
insertMsgToUs();
}
else {
base.Response.Redirect("Login.aspx");
}
}
例四：
verificationcode.aspx.cs：
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Drawing; using System.Drawing.Imaging; using System.Drawing.Drawing2D; using System.IO; public partial class verificationcode : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { Response.Cache.SetCacheability(HttpCacheability.NoCache); string vVerificationCode = RandomCode("verificationcode", 4, true); Add("verificationcode", vVerificationCode.ToLower()); //Session中保存验证码 CreateImage(vVerificationCode); } /// <summary> /// 从字符串里随机得到，规定个数的字符串. /// </summary> /// <param name="allChar"></param> /// <param name="CodeCount"></param> /// <param name="tSleep">是否要在生成前将当前线程阻止以避免重复</param> /// <returns></returns> public static string RandomCode(string byChar, int CodeCount, bool tSleep) { string randomChar = ""; switch (byChar) { case "num": randomChar = "1,2,3,4,5,6,7,8,9"; break; case "maxen": randomChar = "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"; break; case "minien": randomChar = "a,b,c,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z"; break; case "minien&num": randomChar = "1,2,3,4,5,6,7,8,9,a,b,c,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z"; break; case "all": randomChar = "1,2,3,4,5,6,7,8,9,a,b,c,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"; break; case "verificationcode": randomChar = "2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,U,V,W,X,Y,Z"; break; default: randomChar = byChar; break; } randomChar = randomChar.Replace(",", ""); string RandomCode = ""; if (tSleep) { System.Threading.Thread.Sleep(3); } char[] allCharArray = randomChar.ToCharArray(); int n = allCharArray.Length; System.Random random = new Random(~unchecked((int)DateTime.Now.Ticks)); for (int i = 0; i < CodeCount; i++) { int rnd = random.Next(0, n); RandomCode += allCharArray[rnd]; } return RandomCode; } /// <summary> /// 添加Session，有效期为20分钟 /// </summary> /// <param name="strSessionName">Session对象名称</param> /// <param name="strValues">Session值数组</param> public static void Add(string strSessionName, string strValue) { HttpContext.Current.Session[strSessionName] = strValue; HttpContext.Current.Session.Timeout = 20; } #region 验证码 /// <summary> /// 创建验证码图片 /// </summary> /// <param name="randomcode">验证码</param> private void CreateImage(string randomcode) { int randAngle = 40; //随机转动角度 int mapwidth = (int)(randomcode.Length * 18); Bitmap map = new Bitmap(mapwidth, 24);//创建图片背景 Graphics graph = Graphics.FromImage(map); graph.Clear(Color.White);//清除画面，填充背景 //graph.DrawRectangle(new Pen(Color.Silver, 0), 0, 0, map.Width - 1, map.Height - 1);//画一个边框 Random rand = new Random(); //验证码旋转，防止机器识别 char[] chars = randomcode.ToCharArray();//拆散字符串成单字符数组 //文字距中 StringFormat format = new StringFormat(StringFormatFlags.NoClip); format.Alignment = StringAlignment.Center; format.LineAlignment = StringAlignment.Center; //定义颜色 Color[] c = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.DarkBlue }; //画图片的背景噪音线 for (int i = 0; i < 2; i++) { int x1 = rand.Next(10); int x2 = rand.Next(map.Width - 10, map.Width); int y1 = rand.Next(map.Height); int y2 = rand.Next(map.Height); graph.DrawLine(new Pen(c[rand.Next(7)]), x1, y1, x2, y2); } for (int i = 0; i < chars.Length; i++) { int cindex = rand.Next(7); int findex = rand.Next(5); Font f = new System.Drawing.Font("Arial", 18, System.Drawing.FontStyle.Regular);//字体样式(参数2为字体大小) Brush b = new System.Drawing.SolidBrush(c[cindex]); Point dot = new Point(12, 16); float angle = rand.Next(-randAngle, randAngle);//转动的度数 graph.TranslateTransform(dot.X, dot.Y);//移动光标到指定位置 graph.RotateTransform(angle); graph.DrawString(chars[i].ToString(), f, b, 1, 1, format); graph.RotateTransform(-angle);//转回去 graph.TranslateTransform(2, -dot.Y);//移动光标到指定位置 } //生成图片 System.IO.MemoryStream ms = new System.IO.MemoryStream(); map.Save(ms, System.Drawing.Imaging.ImageFormat.Gif); Response.ClearContent(); Response.ContentType = "image/gif"; Response.BinaryWrite(ms.ToArray()); graph.Dispose(); map.Dispose(); } #endregion }
页面前面
<input name="txtCode" runat="server" type="text" id="txtCode" class="txtinput1" />
<img src="verificationcode.aspx" onclick="this.src='verificationcode.aspx?r=' + Math.random();" alt="点击刷新验证码" style="cursor: pointer;"/>
页面后面
protected void btnSendMsg_Click(object sender, EventArgs e) {
if ((this.Session["verificationcode"] != null) && (this.Session["verificationcode"].ToString() != "")) {
if (this.Session["verificationcode"].ToString() != this.txtCode.Value.ToLower()) {
ScriptManager.RegisterStartupScript(this, GetType(), "msg", "alert('验证码不正确!')", true);
this.Session["verificationcode"] = null;
return;
}
this.Session["verificationcode"] = null;
insertMsgToUs();
}
else {
base.Response.Redirect("Login.aspx");
}
}
再度应用的写法：
#region 生成随机的验证码 /// <summary> /// 生成随机的验证码 /// </summary> /// <returns></returns> private string GenerateCheckCode() { int number; char code; string checkCode = String.Empty; System.Random random = new Random(); for (int i = 0; i < 5; i++) { number = random.Next(); if (number % 2 == 0) code = (char)('0' + (char)(number % 10)); else code = (char)('A' + (char)(number % 26)); checkCode += code.ToString(); } //去掉0和大小写o checkCode = checkCode.Replace("0", "1").Replace("o", "1").Replace("O", "1"); //if (!Request.Browser.Cookies) //{ // Session["validateCode"] = checkCode; //} //Response.Cookies.Add(new HttpCookie("validateCode", checkCode)); return checkCode; } /// <summary> /// 生成随机的验证码 /// </summary> /// <returns></returns> public string CreateCodeImage() { char[] chars = "23456789QWERTYUPASDFGHJKLZXCVBNMqwertyupasdfghjkzxcvbnm".ToCharArray(); Random random = new Random(); string validateCode = string.Empty; for (int i = 0; i < 5; i++) validateCode += chars[random.Next(0, chars.Length)].ToString(); return validateCode; } /// <summary> /// 生成随机的验证码 /// </summary> /// <returns></returns> public string CreateVerifyCode() { string codeSerial = "1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,j,k,m,n,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,J,K,M,N,P,Q,R,S,T,U,V,W,X,Y,Z"; string[] arr = codeSerial.Split(','); string code = ""; int randValue = -1; Random rand = new Random(unchecked((int)DateTime.Now.Ticks)); for (int i = 0; i < 5; i++) { randValue = rand.Next(0, arr.Length - 1); code += arr[randValue]; } return code; } /// <summary> /// 生成随机的验证码 /// </summary> /// <returns></returns> private string CreateValidate() { string ValidateCode = string.Empty; string AllChar = "1,2,3,4,5,6,7,8,9,0,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z"; //将验证码中所有的字符保存在一个字符串数组中 string[] CharArray = AllChar.Split(','); int Temp = -1; //生成一个随机对象 Random RandCode = new Random(); //根据验证码的位数循环 for (int i = 0; i < 5; i++) { //主要是防止生成相同的验证码 if (Temp != -1) { //加入时间的刻度 RandCode = new Random(i * Temp * ((int)DateTime.Now.Ticks)); } int t = RandCode.Next(35); if (Temp == t) { //相等的话重新生成 CreateValidate(); } Temp = t; ValidateCode += CharArray[Temp]; } //错误检测,去除超过指定位数的验证码 if (ValidateCode.Length > 5) ValidateCode = ValidateCode.Remove(5); return ValidateCode; } #endregion
#region 将生成的验证码在网页上画出 /// <summary> /// 将生成的验证码在网页上画出 /// </summary> /// <param name="checkCode"></param> private void CreateCheckCodeImage(string checkCode) { if (checkCode == null || checkCode.Trim() == String.Empty) return; Bitmap image = new Bitmap((int)Math.Ceiling(checkCode.Length * 12.5), 22); Graphics g = Graphics.FromImage(image); try { //生成随机生成器 Random random = new Random(); //清空图片背景色 g.Clear(Color.White); //画图片的背景噪音线 for (int i = 0; i < 25; i++) { int x1 = random.Next(image.Width); int x2 = random.Next(image.Width); int y1 = random.Next(image.Height); int y2 = random.Next(image.Height); g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2); } Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic)); LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true); g.DrawString(checkCode, font, brush, 2, 2); //画图片的前景噪音点 for (int i = 0; i < 100; i++) { int x = random.Next(image.Width); int y = random.Next(image.Height); image.SetPixel(x, y, Color.FromArgb(random.Next())); } //画图片的边框线 g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1); System.IO.MemoryStream ms = new System.IO.MemoryStream(); image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif); Response.ClearContent(); Response.ContentType = "image/Gif"; Response.BinaryWrite(ms.ToArray()); } finally { g.Dispose(); image.Dispose(); } } #endregion /// <summary> /// 将生成的验证码在网页上画出 /// </summary> /// <param name="checkCode"></param> private void CreateImage(string checkCode) { string[] fonts = { "Arial", "Georgia" }; Color[] colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple }; ////文字距中 //StringFormat format = new StringFormat(StringFormatFlags.NoClip); //format.Alignment = StringAlignment.Center; //format.LineAlignment = StringAlignment.Center; int letterWidth = 15;//单个字体的宽度范围 //int imageHeight = 27;//单个字体的高度范围 //int imageWidth = checkCode.Length * letterWidth + 5; int fontSize = 12; int Padding = 2; int randAngle = 40; //随机转动角度 int fWidth = fontSize + Padding; int imageWidth = (int)(checkCode.Length * fWidth) + 4 + Padding * 2; int imageHeight = fontSize * 2 + Padding; Random newRandom = new Random(); Bitmap image = new Bitmap(imageWidth, imageHeight); Graphics g = Graphics.FromImage(image); //生成随机生成器 Random random = new Random(); //白色背景 g.Clear(Color.White); //画图片的背景噪音线 for (int i = 0; i < 10; i++) { int x1 = random.Next(image.Width); int x2 = random.Next(image.Width); int y1 = random.Next(image.Height); int y2 = random.Next(image.Height); g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2); } //画图片的前景噪音点 for (int i = 0; i < 10; i++) { int x = random.Next(image.Width); int y = random.Next(image.Height); image.SetPixel(x, y, Color.FromArgb(random.Next())); } //随机字体和颜色的验证码字符 int findex, cindex; for (int int_index = 0; int_index < checkCode.Length; int_index++) { findex = newRandom.Next(fonts.Length - 1); cindex = newRandom.Next(colors.Length - 1); string str_char = checkCode.Substring(int_index, 1); Brush newBrush = new SolidBrush(GetRandomColor()); //Brush newBrush = new SolidBrush(colors[cindex]); Point thePos = new Point(int_index * letterWidth + 1 + newRandom.Next(3), 1 + newRandom.Next(3));//5+1+a+s+p+x //Point thePos = new Point(12, 16); //float angle = newRandom.Next(-randAngle, randAngle);//转动的度数 //g.TranslateTransform(thePos.X, thePos.Y);//移动光标到指定位置 //g.RotateTransform(angle); g.DrawString(str_char, new Font(fonts[findex], 14, FontStyle.Bold), newBrush, thePos); //g.DrawString(checkCode[int_index].ToString(), new Font(fonts[findex], 14, FontStyle.Bold), newBrush, 1, 1, format); //g.RotateTransform(-angle);//转回去 //g.TranslateTransform(2, -thePos.Y);//移动光标到指定位置 } //灰色边框 //g.DrawRectangle(new Pen(Color.LightGray, 1), 0, 0, imageWidth - 1, (imageHeight - 1)); g.DrawRectangle(new Pen(Color.Gainsboro, 0), 0, 0, image.Width - 1, image.Height - 1); //图片扭曲 image = TwistImage(image, true, 3, 4); //image = TwistImage(image, true, 8, 4); //image = TwistImage(image, true, 0, 0); //将生成的图片发回客户端 System.IO.MemoryStream ms = new System.IO.MemoryStream(); image.Save(ms, System.Drawing.Imaging.ImageFormat.Png); Response.ClearContent(); //需要输出图象信息 要修改HTTP头 Response.ContentType = "image/Png"; // Response.ContentType = "image/Gif"; // Response.ContentType = "image/Jpeg"; Response.BinaryWrite(ms.ToArray()); g.Dispose(); image.Dispose(); } /// <summary> /// 正弦曲线Wave扭曲图片 /// </summary> /// <param name="srcBmp">图片路径</param> /// <param name="bXDir">如果扭曲则选择为True</param> /// <param name="nMultValue">波形的幅度倍数，越大扭曲的程度越高，一般为3</param> /// <param name="dPhase">波形的起始相位，取值区间[0-2*PI)</param> /// <returns></returns> private System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase) { const double PI2 = 3.1415926535897932384626433832795; const double PI = 6.283185307179586476925286766559; 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; } /// <summary> /// 生成随机颜色 /// </summary> /// <returns></returns> private Color GetRandomColor() { Random RandomNum_First = new Random((int)DateTime.Now.Ticks); System.Threading.Thread.Sleep(RandomNum_First.Next(50)); Random RandomNum_Sencond = new Random((int)DateTime.Now.Ticks); int int_Red = RandomNum_First.Next(210); int int_Green = RandomNum_Sencond.Next(180); int int_Blue = (int_Red + int_Green > 300) ? 0 : 400 - int_Red - int_Green; int_Blue = (int_Blue > 255) ? 255 : int_Blue; return Color.FromArgb(int_Red, int_Green, int_Blue); } #endregion
/// <summary> /// 显示验证码图片 /// </summary> public void CheckCodeImage() { string code = GenerateCheckCode(); //string code = CreateCodeImage(); //string code = CreateVerifyCode(); //string code = CreateValidate(); Session["checkImgCode"] = code; //CreateCheckCodeImage(code); CreateImage(code); }
var flag = false; if (Session["checkImgCode"] != null) { if (String.Compare(Session["checkImgCode"].ToString(), imgCode, true) != 0) { res.msg = "图形验证码输入错误"; } else { flag = true; } } else { res.msg = "图形验证码生成错误"; }
<img src="@Url.Content(LocalUrl + "Register/CheckCodeImage")" id="changeImgCode" class="changeImgCode" /> $("#changeImgCode").click(function () { var _this = $(this); _this.attr("src", _this.attr("src") + "?v=" + Math.random()); });
gif验证码生成参考：http://blog.csdn.net/mowuyan/article/details/5431429