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C# 生成简单验证码
网站登录总是会用到验证码,生成验证码对于C#来说很简单。因为有专门封装好的GDI+类可以直接调用使用具体代码如下
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using System.Web.UI; 6 using System.Web.UI.WebControls; 7 using System.Drawing; 8 9 namespace Ajax.验证码10 {11 public partial class Yanma : System.Web.UI.Page12 {13 private int CodeNum = 4;14 private string codeNum = "";15 protected void Page_Load(object sender, EventArgs e)16 {17 VeriflcationCode();18 HuaCode(codeNum);19 }20 21 private void VeriflcationCode()22 {23 //生成验证码24 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";25 string[] StrChar = AllChar.Split(‘,‘);26 Random rd = new Random();27 string Codes = "";28 for (int i = 0; i < CodeNum; i++)29 {30 Codes += StrChar[rd.Next(0, 35)];31 }32 codeNum = Codes;33 Session["VerCode"] = Codes; 34 }35 36 private void HuaCode(string Codes)37 {38 int iwidth = (int)(Codes.Length * 17);//定义画布的宽39 System.Drawing.Bitmap images = new System.Drawing.Bitmap(iwidth, 25);//声明一个画布类,初始化图片的宽和高40 41 Graphics g = Graphics.FromImage(images);42 Font f = new Font("Arial", 14);//定义文字类型43 Brush b = new System.Drawing.SolidBrush(Color.Black);//文字颜色 黑色44 Brush r = new System.Drawing.SolidBrush(Color.FromArgb(166, 8, 8));//文字颜色 45 g.Clear(System.Drawing.ColorTranslator.FromHtml("#99C1CB"));//背景色46 47 char[] ch = Codes.ToCharArray();48 for (int i = 0; i < ch.Length; i++)49 {50 if (ch[i] >= ‘0‘ && ch[i] <= ‘9‘)51 {52 //数字用红色显示 53 g.DrawString(ch[i].ToString(), f, r, 3 + (i * 14), 3);//将文字画出 文字、字体类型、字体颜色、字体间距、字体于顶部间距54 }55 else56 { //字母用黑色显示57 g.DrawString(ch[i].ToString(), f, b, 3 + (i * 14), 3);58 }59 }60 61 //for循环用来生成一些随机的水平线62 Pen blackPen = new Pen(Color.Black, 0);63 Random rand = new Random();64 for (int i = 0; i < 5; i++)65 {66 int y = rand.Next(images.Height);67 g.DrawLine(blackPen, 0, y, images.Width, y);68 }69 70 71 System.IO.MemoryStream ms = new System.IO.MemoryStream();72 images.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);73 //history back 不重复 74 Response.Cache.SetNoStore();//这一句 75 Response.ClearContent();76 Response.ContentType = "image/Jpeg";77 Response.BinaryWrite(ms.ToArray());78 g.Dispose();79 images.Dispose();80 }
效果为:
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