代码:
复制代码 代码如下: public void ProcessRequest(HttpContext context) { context.Response.ContentType = "image/jpeg"; //创建位图,并且给指定边框的宽高 using (Image img=new Bitmap(80,25)) {
//创建画家对象,在img对象画字符串 using (Graphics g=Graphics.FromImage(img)) { //设置位图的背景颜色,默认是黑色 g.Clear(Color.White); //设置验证码的宽高, img.Width-1, img.Height-1主要是背景颜色覆盖了边框线 g.DrawRectangle(Pens.Black, 0, 0, img.Width-1, img.Height-1); //传100个噪点,传画家对象,位图对象 DrawPoint(100, g, img); //画4个验证码的字符串 string vcode=GetCode(4);//vcode这里可以赋值给Cookie
g.DrawString(vcode, new Font("Arial", 14, FontStyle.Strikeout | FontStyle.Strikeout), // FontStyle字体的样式,多个样式,需要|线
Brushes.Black, new RectangleF(r.Next(20), r.Next(7), img.Width, img.Height)); img.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);//保存验证码对象,指定是Jpeg格式
} } }
//画噪点方法
void DrawPoint(int point,Graphics g,Image img) { for (int i = 0; i < point; i++) { int x = r.Next(img.Width); int y = r.Next(img.Width); g.DrawLine(Pens.Red, new Point(x, y), new Point(x+2, y+2));
} }
//随机数 Random r = new Random();
//画字符创 string GetCode(int point) { string txtStr = "ASF2345WE5R9F3HMBCZ455K";//这里的string字符串将会转成 char数组,阿拉伯数字1和小写字母l最好别写在里面,会搞胡乱。 char[] charArr = txtStr.ToArray(); int num = 0; string code = ""; for (int i = 0; i <point; i++) { num = r.Next(charArr.Length); code +=charArr[num]; } return code; }
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