asp.net中的比较完美的验证码
本文转载:http://blog.csdn.net/zjk20108023/article/details/7836174
要实现如图的效果的验证码,分以下步骤:
第一、布局好调用验证码的登录页面(命名:Login.aspx),注意:验证码位置可以是服务器控件 Image,也可以是html标签写的<img>,但是图片url就是一个页面(命名:ValidateCode.aspx)(将在下面讲述。)比如:<asp:Image ID=“vcImg” ImageUrl="~/ValidateCode.aspx" runat="server" />
第二、生成类文件 (命名:validatedCode)
- using System;
- using System.Data;
- using System.Configuration;
- using System.Linq;
- using System.Web;
- using System.Web.Security;
- using System.Web.UI;
- using System.Web.UI.HtmlControls;
- using System.Web.UI.WebControls;
- using System.Web.UI.WebControls.WebParts;
- using System.Xml.Linq;
- using System.Drawing;
- using System.IO;
- using System.Drawing.Imaging;
- /// <summary>
- /// Summary description for validatedCode
- /// </summary>
- public class validatedCode
- {
- #region 验证码长度(默认6个验证码的长度)
- 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)
- int fontSize = 40;
- 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 = "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";
- 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(Edit By 51aspx.com)
- /// </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(Add By 51aspx.com)
- image = TwistImage(image, true, 8, 4);
- 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
- }
代码中有注释,所以我就不多说了。
第三、生成调用类文件的网页(ValidateCode.aspx),在该页面的后台代码(ValidateCode.aspx.cs文件)的Page_Load事件中写如下代码:
- protected void Page_Load(object sender, EventArgs e)
- {
- validatedCode v = new validatedCode();
- string code = v.CreateVerifyCode(); //取随机码
- v.CreateImageOnPage(code, this.Context); // 输出图片
- Session["CheckCode"] = code; //Session 取出验证码
- }
- protected void btnLogin_Click(object sender, EventArgs e)
- {
- string vCode = Session["CheckCode"].ToString();
- if (txtValidatedcode.Text.Trim().ToUpper() == vCode.ToUpper())
- {
- ScriptManager.RegisterStartupScript(this.Page, this.GetType(), "Startup", "alert('ValidatedCode is right!');", true);
- }
- }
作者:阿笨
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