public void CreateValidateCode()
{
ValidateCoder vc = new ValidateCoder();
string code = vc.CreateValidateCode(4);
Session["ValidateCode"] = code;
byte[] bytes = vc.CreateValidateGraphic(code);
Response.ClearContent();
Response.ContentType = "image/Gif";
Response.BinaryWrite(bytes);
Response.Flush();
Response.End();
}
/// <summary>
/// 创建验证码的图片
/// </summary>
/// <param name="validateCode">验证码</param>
/// <param name="hasBorder">是否需要画边框</param>
public byte[] CreateValidateGraphic(string validateCode, bool hasBorder = false)
{
Bitmap image = new Bitmap(ValidateCoder.GetImageWidth(validateCode.Length), ValidateCoder.GetImageHeight());
Graphics g = Graphics.FromImage(image);
try
{
//生成随机生成器
Random random = new Random();
//清空图片背景色
g.Clear(Color.White);
//画图片的干扰线
for (int i = 0; i < 25; 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.Silver), x1, y1, x2, y2);
}
Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
Color.Blue, Color.DarkRed, 1.2f, true);
g.DrawString(validateCode, font, brush, 3, 2);
//画图片的前景干扰点
for (int i = 0; i < 100; i++)
{
int x = random.Next(image.Width);
int y = random.Next(image.Height);
image.SetPixel(x, y, Color.FromArgb(random.Next()));
}
//画图片的边框线
if (hasBorder)
{
g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
}
//保存图片数据
MemoryStream stream = new MemoryStream();
image.Save(stream, ImageFormat.Jpeg);
//输出图片流
return(stream.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
