验证码类源代码
以 下是一个验证码类源代码，使用方法：建立一个ValidateImg.aspx，后台代码里写：ValidateImage img = new ValidateImage();验证的地方：ValidateImage.Validate(txtCode.Text.Trim())
/// <summary>
/// 验证码类
/// </summary>
public class ValidateImage
{
/// <summary>
/// 要显示的文字
/// </summary>
public string Text
{
get { return this.text; }
}
/// <summary>
/// 图片
/// </summary>
public Bitmap Image
{
get { return this.image; }
}
/// <summary>
/// 宽度
/// </summary>
public int Width
{
get { return this.width; }
}
/// <summary>
/// 高度
/// </summary>
public int Height
{
get { return this.height; }
}
private string text;
private int width;
private int height;
private Bitmap image;
private static byte[] randb = new byte[4];
private static Random rand = new Random();
public ValidateImage()
{
text = rand.Next(1000, 9999).ToString();
System.Web.HttpContext.Current.Session["CheckCode"] = text;
this.width = (int)Math.Ceiling(text.Length * 16.5);
this.height = 30;
GenerateImage();
System.Web.HttpContext.Current.Response.ContentType = "image/pjpeg";
Image.Save(System.Web.HttpContext.Current.Response.OutputStream, ImageFormat.Jpeg);
}
public static bool Validate(string input)
{
return System.Web.HttpContext.Current.Session["CheckCode"] != null && System.Web.HttpContext.Current.Session["CheckCode"].ToString().Equals(input);
}
~ValidateImage()
{
Dispose(false);
}
public void Dispose()
{
GC.SuppressFinalize(this);
this.Dispose(true);
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
this.image.Dispose();
}
private FontFamily[] fonts = {
new FontFamily("Times New Roman"),
new FontFamily("Georgia"),
new FontFamily("Arial"),
new FontFamily("Comic Sans MS")
};
public int Next(int max)
{
return rand.Next(max);
}
/// <summary>
/// 生成验证码图片
/// </summary>
private void GenerateImage()
{
Bitmap bitmap = new Bitmap(this.width, this.height, PixelFormat.Format32bppArgb);
Graphics g = Graphics.FromImage(bitmap);
Rectangle rect = new Rectangle(0, 0, this.width, this.height);
g.SmoothingMode = SmoothingMode.AntiAlias;
g.Clear(Color.White);
//int emSize = Next(3) + 15;//(int)((this.width - 20) * 2 / text.Length);
//int emSize = (int)((this.width - 20) * 2 / text.Length);
int emSize = 12;
FontFamily family = fonts[Next(fonts.Length - 1)];
Font font = new Font(family, emSize, FontStyle.Bold);
SizeF measured = new SizeF(0, 0);
SizeF workingSize = new SizeF(this.width, this.height);
while (emSize > 2 && (measured = g.MeasureString(text, font)).Width > workingSize.Width || measured.Height > workingSize.Height)
{
font.Dispose();
font = new Font(family, emSize -= 2);
}
SolidBrush drawBrush = new SolidBrush(Color.FromArgb(Next(100), Next(80), Next(80)));
for (int x = 0; x < 1; x++)
{
Pen linePen = new Pen(Color.FromArgb(Next(150), Next(100), Next(100)), 1);
g.DrawLine(linePen, new PointF(0.0F + Next(2), 0.0F + Next(this.height)), new PointF(0.0F + Next(this.width), 0.0F + Next(this.height - 10)));
}
for (int x = 0; x < this.text.Length; x++)
{
drawBrush.Color = Color.FromArgb(Next(150) + 20, Next(150) + 20, Next(150) + 20);
PointF drawPoint = new PointF(0.0F + Next(5) + x * 15, 2.0F + Next(4));
g.DrawString(this.text[x].ToString(), font, drawBrush, drawPoint);
}
double distort = rand.Next(5, 10) * (Next(10) == 1 ? 1 : -1);
using (Bitmap copy = (Bitmap)bitmap.Clone())
{
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
int newX = (int)(x + (distort * Math.Sin(Math.PI * y / 84.0)));
int newY = (int)(y + (distort * Math.Cos(Math.PI * x / 54.0)));
if (newX < 0 || newX >= width) newX = 0;
if (newY < 0 || newY >= height) newY = 0;
bitmap.SetPixel(x, y, copy.GetPixel(newX, newY));
}
}
}
//g.DrawRectangle(new Pen(Color.Silver), 0, 0, bitmap.Width - 1, bitmap.Height - 1);
font.Dispose();
drawBrush.Dispose();
g.Dispose();
this.image = bitmap;
}
}
