public string RandomWords(int maxLength)
{
string words = "1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,P,Q,R,S,T,U,V,W,X,Y,Z";
string[] wordsArr = words.Split(new char[] { ',' });
Random random = new Random();
string code = string.Empty;
for (int i = 0; i < maxLength; i++)
{
code += wordsArr[random.Next(0, 33)];
}
return code;
}
public void CreateImage(string content)
{
//图片长度
int imageWidth = (int)(content.Length * 15);
//创建位图
Bitmap image = new Bitmap(imageWidth, 23);
//根据图片大小生成画板
Graphics grap = Graphics.FromImage(image);
//字体
Font font = new Font("Arial", 14, FontStyle.Italic);
//笔刷
Brush brush = new SolidBrush(Color.FromArgb(204, 0, 240));
//生成画板背景
grap.Clear(Color.FromArgb(235,235,235));
//画笔
Pen pen = new Pen(Color.White,1);
//生成三条背景线
Random random = new Random();
for(int i = 0; i < 3; i++)
{
int y = random.Next(image.Height);
grap.DrawLine(pen,0,y,image.Width,y);
}
//在画板上画随机码内容
grap.DrawString(content,font,brush,1,1);
//增加随机噪点
Random randomPoints = new Random((int)DateTime.Now.Ticks);
Random randomXY = new Random(unchecked((int)DateTime.Now.Ticks));
for (int i = 0; i < 10; i++)
{
int x = random.Next(image.Width);
int y = random.Next(image.Height);
grap.DrawLine(new Pen(Color.FromArgb(randomPoints.Next(0, 255), randomPoints.Next(0, 255), randomPoints.Next(0, 255)), 1), x, y, x + randomXY.Next(0, 10), y + randomXY.Next(0, 10));
}
for (int i = 0; i < 100; i++)
{
int x = random.Next(image.Width);
int y = random.Next(image.Height);
grap.DrawLine(new Pen(Color.FromArgb(randomPoints.Next(0, 255), randomPoints.Next(0, 255), randomPoints.Next(0, 255)), 0), x, y, x + randomXY.Next(0, 3), y + randomXY.Next(0, 3));
}
//以流的形式返回图片
System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms,System.Drawing.Imaging.ImageFormat.Jpeg);
Response.ClearContent();
Response.ContentType ="image/Jpeg";
Response.BinaryWrite(ms.ToArray());
grap.Dispose();
image.Dispose();
}