/// <summary>
/// 验证码图片
/// </summary>
/// <param name="context"></param>
/// <param name="options"></param>
public static void Captcha(HttpContextWrapper context, CaptchaModel options)
{
if (Equals(options, null)) options = CaptchaOptions();
int width = options.Width, height = options.Height;
string value = options.Value, cookieName = options.CookieName;
var colors = options.Colors;
var fonts = options.Fonts;
var bmp = new Bitmap(width, height);
var g = Graphics.FromImage(bmp);
g.Clear(options.BackGroundColor);
g.TextRenderingHint = TextRenderingHint.AntiAliasGridFit;
for (var i = 0; i < 3; i++)
{
var x1 = StringConvert.SysRandom.Next(width);
var y1 = StringConvert.SysRandom.Next(height);
var x2 = StringConvert.SysRandom.Next(width);
var y2 = StringConvert.SysRandom.Next(height);
var clr = colors[StringConvert.SysRandom.Next(colors.Length)];
g.DrawLine(new Pen(clr), x1, y1, x2, y2);
}
for (var i = 0; i < value.Length; i++)
{
var fnt = fonts[StringConvert.SysRandom.Next(fonts.Length)];
var ft = new Font(fnt, 16);
var clr = colors[StringConvert.SysRandom.Next(colors.Length)];
g.DrawString(value[i].ToString(), ft, new SolidBrush(clr), (float)i * 20 + 20, 6);
}
for (var i = 0; i < 50; i++)
{
var x = StringConvert.SysRandom.Next(bmp.Width);
var y = StringConvert.SysRandom.Next(bmp.Height);
var clr = colors[StringConvert.SysRandom.Next(colors.Length)];
bmp.SetPixel(x, y, clr);
}
var ms = new MemoryStream();
try
{
bmp.Save(ms, ImageFormat.Jpeg);
context.Response.ClearContent();
context.Response.ContentType = "image/jpg";
context.Response.BinaryWrite(ms.ToArray());
}
finally
{
bmp.Dispose();
g.Dispose();
ms.Dispose();
}
CookieHelper.SetCookie(context, cookieName, BaseCryption.SignData(cookieName, value, HmacType.Sha1));
}
/// <summary>
/// 验证码默认选项
/// </summary>
/// <returns></returns>
private static CaptchaModel CaptchaOptions()
{
var options = new CaptchaModel
{
Width = 150,
Height = 30,
CookieName = "CAPTCHAModel",
Colors = new[] { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.DarkBlue },
BackGroundColor = Color.White,
Characters = "23456789ABCDEFGHJKLMNPRSTWXY",
Fonts = new[] { "Times New Roman", "MS Mincho", "Book Antiqua", "Gungsuh", "PMingLiU", "Impact" },
Value = string.Empty
};
for (var i = 0; i < 6; i++)
{
options.Value += options.Characters[StringConvert.SysRandom.Next(options.Characters.Length)];
}
return options;
}
/// <summary>
/// 验证验证码是否正确
/// </summary>
/// <param name="context"></param>
/// <param name="options"></param>
/// <param name="value"></param>
/// <returns></returns>
public static bool VerifyCaptcha(HttpContextWrapper context, CaptchaModel options, string value)
{
if (Equals(options, null)) options = CaptchaOptions();
return BaseCryption.VerifyData(options.CookieName, CookieHelper.GetCookie(context, options.CookieName), HmacType.Sha1);
}