C# 创建验证码图片

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Web.UI.WebControls;

public class ValidateCodeCreator
{
/// <summary>
///     产生验证码
/// </summary>
/// <param name="codeLength">验证码长度</param>
/// <returns></returns>
public string CreateCode(int codeLength)
{
string so =
"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,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
string[] strArr = so.Split(',');
string code = "";
Random rand = new Random();
for (int i = 0; i < codeLength; i++)
{
code += strArr[rand.Next(0, strArr.Length)];
}
return code;
}

/// <summary>
///     产生验证图片
/// </summary>
/// <param name="code"></param>
public byte[] CreateCodeImage(string code)
{
Bitmap image = new Bitmap(50, 20);
Graphics g = Graphics.FromImage(image);
try
{
WebColorConverter ww = new WebColorConverter();
g.Clear((Color) ww.ConvertFromString("#FAE264"));
Random random = new Random();
//画图片的背景噪音线
for (int i = 0; i < 12; i++)
{
int x1 = random.Next(image.Width);
int x2 = random.Next(image.Width);
int y1 = random.Next(image.Height);
int y2 = random.Next(image.Height);
g.DrawLine(new Pen(Color.LightGray), x1, y1, x2, y2);
}
Font font = new Font("Arial", 13, FontStyle.Bold | FontStyle.Italic);
LinearGradientBrush brush = new LinearGradientBrush(
new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.Gray, 1.2f, true);
g.DrawString(code, font, brush, 0, 0);
//画图片的前景噪音点
//for (int i = 0; i < 10; i++)
//{
//    int x = random.Next(image.Width);
//    int y = random.Next(image.Height);
//    image.SetPixel(x, y, Color.White);
//}
//画图片的边框线
// g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
MemoryStream ms = new MemoryStream();
image.Save(ms, ImageFormat.Gif);
return ms.ToArray();
}
finally
{
g.Dispose();
image.Dispose();
}
}
}