由字母或数字组成的随机验证码代码,CSharp代码库,德仔网

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【CSharp】由字母或数字组成的随机验证码

作者: / 发布于2014/10/21/ 717


	public partial class ValidateImg : System.Web.UI.Page
	 {
	 protected void Page_Load(object sender, EventArgs e)
	 {
	 char[] chars = "0123456789abcdefghijklmnopqrstuvwxyz".ToCharArray();
	 System.Random random = new Random();
	
	 string validateCode = string.Empty;
	 for (int i = 0; i < 4; i++)
	 {
	 char rc = chars[random.Next(0, chars.Length)];
	 if (validateCode.IndexOf(rc) > -1)
	 {
	 i--;
	 continue;
	 }
	 validateCode += rc;
	 }
	 Session["ValidateCode"] = validateCode;
	 CreateImage(validateCode);
	 }
	
	 /// <summary>
	 /// 创建图片
	 /// </summary>
	 /// <param name="checkCode"></param>
	 private void CreateImage(string checkCode)
	 {
	 int iwidth = (int)(checkCode.Length * 11);
	 System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 19);
	 Graphics g = Graphics.FromImage(image);
	 g.Clear(Color.White);
	 //定义颜色
	 Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Chocolate, Color.Brown, Color.DarkCyan, Color.Purple };
	 Random rand = new Random();
	
	 //输出不同字体和颜色的验证码字符
	 for (int i = 0; i < checkCode.Length; i++)
	 {
	 int cindex = rand.Next(7);
	 Font f = new System.Drawing.Font("Microsoft Sans Serif", 11);
	 Brush b = new System.Drawing.SolidBrush(c[cindex]);
	 g.DrawString(checkCode.Substring(i, 1), f, b, (i * 10) + 1, 0, StringFormat.GenericDefault);
	 }
	 //画一个边框
	 g.DrawRectangle(new Pen(Color.Black, 0), 0, 0, image.Width - 1, image.Height - 1);
	
	 //输出到浏览器
	 System.IO.MemoryStream ms = new System.IO.MemoryStream();
	 image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
	 Response.ClearContent();
	 Response.ContentType = "image/Jpeg";
	 Response.BinaryWrite(ms.ToArray());
	 g.Dispose();
	 image.Dispose();
	 }
	 }

试试其它关键字

　验证码　　随机验证码　

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