public void RenderImage(System.Web.HttpContext context)
{
RandomWord = SelectRandomWord(5);
//context.Session["authcode"] = RandomWord;
Cookie.SetCookie("authcode", RandomWord);
Bitmap objBMP = new System.Drawing.Bitmap(80, 26);
Graphics objGraphics = System.Drawing.Graphics.FromImage(objBMP);
objGraphics.Clear(BackGroundColor);
// Instantiate object of brush with black color
SolidBrush objBrush = new SolidBrush(RandomTextColor);
Font objFont = null;
int a;
String myFont, str;
//Creating an array for most readable yet cryptic fonts for OCR's
// This is entirely up to developer's discretion
String[] crypticFonts = new String[11];
crypticFonts[0] = "Arial";
crypticFonts[1] = "Verdana";
crypticFonts[2] = "微软雅黑";
crypticFonts[3] = "Impact";
crypticFonts[4] = "Haettenschweiler";
crypticFonts[5] = "Lucida Sans Unicode";
crypticFonts[6] = "Garamond";
crypticFonts[7] = "Courier New";
crypticFonts[8] = "Book Antiqua";
crypticFonts[9] = "Arial Narrow";
crypticFonts[10] = "Estrangelo Edessa";
//Loop to write the characters on image
// with different fonts.
for (a = 0; a <= RandomWord.Length - 1; a++)
{
myFont = crypticFonts[new Random().Next(a)];
objFont = new Font(myFont, 12, FontStyle.Bold | FontStyle.Italic);//| FontStyle.Strikeout);
str = RandomWord.Substring(a, 1);
objGraphics.DrawString(str, objFont, objBrush, a * 13, 5);
objGraphics.Flush();
}
var ms = new MemoryStream();
objBMP.Save(ms, ImageFormat.Jpeg);
context.Response.ClearContent();//.
//清除该页输出缓存，设置该页无缓存
context.Response.Buffer = true;
context.Response.ExpiresAbsolute = System.DateTime.Now.AddMilliseconds(0);
context.Response.Expires = 0;
context.Response.CacheControl = "no-cache";
context.Response.AppendHeader("Pragma", "No-Cache");
context.Response.ContentType = "image/jpeg";
//objBMP.Save(context.Response.OutputStream, ImageFormat.Jpeg);
context.Response.BinaryWrite(ms.ToArray());
objFont.Dispose();
objGraphics.Dispose();
objBMP.Dispose();
context.Response.End();
}
public byte[] RenderImageMvc2(System.Web.HttpContext context, string checkCode)
{
//context.Session["authcode"] = checkCode;
Cookie.SetCookie("authcode", checkCode);
return(GetByteFormImages2(checkCode));
}
//--------------------第二种方式
public void RenderImage2(System.Web.HttpContext context)
{
string chkCode = string.Empty;
//颜色列表，用于验证码、噪线、噪点
//Color[] color = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue };
Color[] color = { Color.Gray, Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown };
//字体列表，用于验证码
string[] font = { "Arial", "Mongolian Baiti", "Times New Roman", "Tahoma", "Mangal", "Mongolian Baiti", "Courier", "PMingLiU", "Impact" };
//验证码的字符集，去掉了一些容易混淆的字符
char[] character = { '2', '3', '4', '5', '6', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' };
Random rnd = new Random();
//生成验证码字符串
for (int i = 0; i < 4; i++)
{
chkCode += character[rnd.Next(character.Length)];
}
//保存验证码
//context.Session["authcode"] = chkCode;
Cookie.SetCookie("authcode", chkCode);
Bitmap bmp = new Bitmap(100, 40);
Graphics g = Graphics.FromImage(bmp);
g.Clear(Color.White);
//画噪线
for (int i = 0; i < 5; i++)
{
int x1 = rnd.Next(100);
int y1 = rnd.Next(40);
int x2 = rnd.Next(100);
int y2 = rnd.Next(40);
Color clr = color[rnd.Next(color.Length)];
g.DrawLine(new Pen(clr), x1, y1, x2, y2);
}
//画验证码字符串
for (int i = 0; i < chkCode.Length; i++)
{
string fnt = font[rnd.Next(font.Length)];
Font ft = new Font(fnt, 18);
Color clr = color[rnd.Next(color.Length)];
g.DrawString(chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 20 + 8, (float)8);
}
//画噪点
for (int i = 0; i < 150; i++)
{
int x = rnd.Next(bmp.Width);
int y = rnd.Next(bmp.Height);
Color clr = color[rnd.Next(color.Length)];
bmp.SetPixel(x, y, clr);
}
//清除该页输出缓存，设置该页无缓存
context.Response.Buffer = true;
context.Response.ExpiresAbsolute = System.DateTime.Now.AddMilliseconds(0);
context.Response.Expires = 0;
context.Response.CacheControl = "no-cache";
context.Response.AppendHeader("Pragma", "No-Cache");
//将验证码图片写入内存流，并将其以 "image/Png" 格式输出
MemoryStream ms = new MemoryStream();
try
{
bmp.Save(ms, ImageFormat.Png);
context.Response.ClearContent();
context.Response.ContentType = "image/Png";
context.Response.BinaryWrite(ms.ToArray());
}
finally
{
//显式释放资源
bmp.Dispose();
g.Dispose();
}
}
