验证码生成页面代码（清理掉没用的html）
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.Threading; using System.Drawing.Text; using System.Drawing.Drawing2D; namespace ZhuoYueE.Dop.Web.UI.FenFa { public partial class CodeImg : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { string randomcode = CreateRandomCode(4); Session["Code"] = randomcode; this.CreateImage(randomcode); } /// 生成随机码 /// </summary> /// <param name="length">随机码个数</param> /// <returns></returns> private string CreateRandomCode(int length) { int rand; char code; string randomcode = String.Empty; //生成一定长度的验证码 System.Random random = new Random(); for (int i = 0; i < length; i++) { start: rand = random.Next(); if (rand % 3 == 0) { code = (char)('A' + (char)(rand % 26)); } else { code = (char)('0' + (char)(rand % 10)); } if (code == '0' || code == 'o' || code == 'O' || code == '1' || code == 'i' || code == 'I' || code == 'l') goto start; randomcode += code.ToString(); } return randomcode; } /// <summary> /// 创建随机码图片 /// </summary> /// <param name="randomcode">随机码</param> private void CreateImage(string randomcode) { //定义颜色 Random rand = new Random(); Color c = Color.FromArgb(rand.Next(155), rand.Next(155), rand.Next(155)); int randAngle = 45; //随机转动角度 int mapwidth = (int)(randomcode.Length * 16); Bitmap map = new Bitmap(mapwidth, 22);//创建图片背景 Graphics graph = Graphics.FromImage(map); graph.Clear(Color.FromArgb(rand.Next(200, 255), rand.Next(200, 255), rand.Next(200, 255)));//清除画面，填充背景 graph.DrawRectangle(new Pen(Color.Black, 0), 0, 0, map.Width - 1, map.Height - 1);//画一个边框 //graph.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;//模式 //背景噪点生成 //Pen blackPen = new Pen(c[cindex], 0); //for (int i = 0; i < 30; i++) //{ // int x = rand.Next(0, map.Width); // int y = rand.Next(0, map.Height); // graph.DrawRectangle(blackPen, x, y, 1, 1); //} //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; //定义字体 string[] font = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体", "Microsoft New Tai Lue" }; int Count = font.Length; LinearGradientBrush b = new LinearGradientBrush( new Point(0, 0), new Point(250, 250), Color.FromArgb(rand.Next(155), rand.Next(155), rand.Next(155)), Color.FromArgb(rand.Next(155), rand.Next(155), rand.Next(155))); for (int i = 0; i < chars.Length; i++) { int findex = rand.Next(Count); //渐变色：起点（0, 0)从红色 --->终点(250, 250)蓝色 Font f = new System.Drawing.Font(font[findex], 14, System.Drawing.FontStyle.Bold);//字体样式(参数2为字体大小) // Brush b = new System.Drawing.SolidBrush(c); Point dot = new Point(14, 14); //graph.DrawString(dot.X.ToString(),fontstyle,new SolidBrush(Color.Black),10,150);//测试X坐标显示间距的 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.DrawString(chars[i].ToString(),fontstyle,new SolidBrush(Color.Blue),1,1,format); graph.RotateTransform(-angle);//转回去 graph.TranslateTransform(-2, -dot.Y);//移动光标到指定位置，每个字符紧凑显示，避免被软件识别 } //画干扰线 Graphics graph1 = Graphics.FromImage(map); int intw = map.Width / 4; int inth = map.Height / 4; for (int i = 0; i < 3; i++) { int x1, x2, y1, y2; x1 = rand.Next(0, intw); y1 = rand.Next(inth, map.Height - inth); Thread.Sleep(5); x2 = rand.Next(map.Width - intw, map.Width); Thread.Sleep(5); y2 = rand.Next(inth, map.Height - inth); graph1.DrawLine(new Pen(b, 1f), x1, y1, x2, y2); } for (int i = 0; i < map.Width; i++) { for (int j = 0; j < map.Height; j++) { Color cc = map.GetPixel(i, j); map.SetPixel(i, j, GetColorByColor(cc)); } } //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(); graph1.Dispose(); map.Dispose(); } private Color GetColorByColor(Color c) { int[] cs = new int[] { c.R, c.G, c.B }; Random r = new Random(); for (int i = 0; i < cs.Length; i++) { if (cs[i] < 50 || cs[i] > 205) continue; int rn = r.Next(-50, 50); cs[i] += rn; } return Color.FromArgb(cs[0], cs[1], cs[2]); } } }
调用代码
<img style="height: 30px" src="codeimg.aspx" id="imgcode" onclick="GetCode()" />
function GetCode() {
document.getElementById("imgcode").src = "codeimg.aspx?t=" + new Date().getTime();
}
效果如下：
