验证码

验证码

已下代码生成一个五个字母的验证码

public class VerifyCodeHelper
{
    public static Bitmap CreateVerifyCode(out string code)
    {
        //建立Bitmap对象，绘图
        Bitmap bitmap = new Bitmap(200, 60);
        Graphics graph = Graphics.FromImage(bitmap);
        graph.FillRectangle(new SolidBrush(Color.White), 0, 0, 200, 60);
        Font font = new Font(FontFamily.GenericSerif, 48, FontStyle.Bold, GraphicsUnit.Pixel);
        Random r = new Random();
        string letters = "ABCDEFGHIJKLMNPQRSTUVWXYZ0123456789";
        StringBuilder sb = new StringBuilder();
        //添加随机的五个字母
        for (int x = 0; x < 5; x++)
        {
            string letter = letters.Substring(r.Next(0, letters.Length - 1), 1);
            sb.Append(letter);
            graph.DrawString(letter, font, new SolidBrush(Color.Black), x * 38, r.Next(0, 15));
        }
        code = sb.ToString();
        //混淆背景
        Pen linePen = new Pen(new SolidBrush(Color.Black), 2);
        for (int x = 0; x < 6; x++)
            graph.DrawLine(linePen, new Point(r.Next(0, 199), r.Next(0, 59)), new Point(r.Next(0, 199), r.Next(0, 59)));
        return bitmap;
    }
}