还是改一个简单点的吧，就用COOKIE实现，而加密那块就先搁着吧~呵呵
以后再加~
要另外加上的命名空间：
using System.Drawing;
using System.Drawing.Drawing2D;
using System.IO;
using System.Drawing.Imaging;
using System.Drawing;
public partial class DiyControls_ValidationCode : System.Web.UI.UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
CreateValidationImage(GenerateValidationCode());
}
/// <summary>
/// 生成验证码
/// </summary>
/// <returns>返回生成的验证码</returns>
private string GenerateValidationCode()
{
int number;
string strCode = String.Empty;
//随机种子的生成，没什么好说的。
Random randomSeed = new Random();
for (int i = 0; i < 4; i++)
{
number = randomSeed.Next();
//这个算法真的巧妙阿，我要认真学习才行！
//大家都知道在ASCII码中，0-9和A-Z分别是48-57，65-90
//而这里用36求余，呵呵，36=（0-9的数）+（A-Z的数）=10+26，这下明白了吧，呵呵。
number = number % 36;
if (number < 10)
{
number += 48;
}
else
{
number += 55;
}
strCode += ((char)number).ToString();
}
//这里用了Cookie来保存验证码，那么当你调用的时候，记得要验证一下浏览器支不支持哦，不然是用不了的阿
Response.Cookies.Add( new HttpCookie ("XiaoLing_ValidationCode", strCode));
return strCode;
}
/// <summary>
/// 生成验证码的图片
/// </summary>
/// <param name="validationCode">图片中的验证码</param>
private void CreateValidationImage(string validationCode)
{
if (validationCode == null||validationCode.Trim()==String.Empty)
{
return;
}
Bitmap validationImage = new Bitmap((int)Math.Ceiling((double)(validationCode.Length * 15)), 20);
Graphics g = Graphics.FromImage(validationImage);
try
{
Random randomSeed = new Random();
//把位图的底色清空，这里把它设为白色
g.Clear(Color.White);
//加上N条干扰线，感觉十来廿条就够了吧
for (int i = 0; i < 20; i++)
{
int x1 = randomSeed.Next(validationImage.Width);
int x2 = randomSeed.Next(validationImage.Width);
int y1 = randomSeed.Next(validationImage.Height);
int y2 = randomSeed.Next(validationImage.Height);
int colorNumber = randomSeed.Next(3);
Color nColor = new Color();
switch (colorNumber)
{
case 0:
nColor = Color.Silver;
break;
case 1:
nColor = Color.SpringGreen;
break;
case 2:
nColor = Color.Tomato;
break;
case 3:
nColor = Color.Violet;
break;
default:
nColor = Color.SeaGreen;
break;
}
g.DrawLine(new Pen(nColor), x1, y1, x2, y2);
}
Font nFont = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
LinearGradientBrush nBrush = new LinearGradientBrush(new Rectangle(0, 0, validationImage.Width, validationImage.Height), Color.Blue, Color.Purple,
//在图片中写上验证码
g.DrawString(validationCode, nFont, nBrush, 2, 2);
//再在上面加N个干扰点
for (int i = 0; i < 100; i++)
{
int x = randomSeed.Next(validationImage.Width);
int y = randomSeed.Next(validationImage.Height);
validationImage.SetPixel(x, y, Color.FromArgb(randomSeed.Next()));
}
//再画个边框
g.DrawRectangle(new Pen(Color.SaddleBrown), 0, 0, validationImage.Width - 1, validationImage.Height - 1);
//弄完了当然要把图片输出了,输出完就给他销毁咯
using (MemoryStream ms = new MemoryStream())
{
validationImage.Save(ms, ImageFormat.Png);
Response.ClearContent();
Response.ContentType = "image/Png";
Response.BinaryWrite(ms.ToArray());
}
}
catch (Exception ex)
{
throw new Exception("这样都有错，真奇怪~！", ex);
}
finally
{
g.Dispose();
validationImage.Dispose();
}
}
}