/// <summary>
/// 生成二维码
/// </summary>
/// <param name="length">二维码长度，默认4个字符</param>
/// <param name="buildImg">是否生成图片，默认true</param>
/// <returns></returns>
public static VerificationCode Create(int length = 4, bool buildImg = true)
{
if (length < 1)
{
throw new ArgumentException("二维码长度必须大于1", "length");
}
int[] randMembers = new int[length];
int[] validateNums = new int[length];
string code = "";
//生成起始序列值
int seekSeek = unchecked ((int)DateTime.Now.Ticks);
Random seekRand = new Random(seekSeek);
int beginSeek = (int)seekRand.Next(0, Int32.MaxValue - length * 10000);
int[] seeks = new int[length];
for (int i = 0; i < length; i++)
{
beginSeek += 10000;
seeks[i] = beginSeek;
}
//生成随机数字
for (int i = 0; i < length; i++)
{
Random rand = new Random(seeks[i]);
int pownum = 1 * (int)Math.Pow(10, length);
randMembers[i] = rand.Next(pownum, Int32.MaxValue);
}
//抽取随机数字
for (int i = 0; i < length; i++)
{
string numStr = randMembers[i].ToString();
int numLength = numStr.Length;
Random rand = new Random();
int numPosition = rand.Next(0, numLength - 1);
validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));
}
//生成验证码
for (int i = 0; i < length; i++)
{
code += validateNums[i].ToString();
}
VerificationCode entity = new VerificationCode {
Code = code, NeedImage = buildImg
};
//生成验证码图片
if (buildImg)
{
BuildImage(ref entity);
}
return(entity);
}
private static void BuildImage(ref VerificationCode entity)
{
if (string.IsNullOrEmpty(entity.Code))
{
throw new ArgumentNullException("entity", "二维码字符不正确");
}
int width = (int)Math.Ceiling(entity.Code.Length * 12.0);
int height = 22;
Bitmap image = new Bitmap(width, height);
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(width);
int x2 = random.Next(width);
int y1 = random.Next(height);
int y2 = random.Next(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, width, height),
Color.Blue, Color.DarkRed, 1.2f, true);
g.DrawString(entity.Code, font, brush, 3, 2);
//画图片的前景干扰点
for (int i = 0; i < 100; i++)
{
int x = random.Next(width);
int y = random.Next(height);
image.SetPixel(x, y, Color.FromArgb(random.Next()));
}
//画图片的边框线
g.DrawRectangle(new Pen(Color.Silver), 0, 0, width - 1, height - 1);
//保存图片数据
using (MemoryStream stream = new MemoryStream())
{
image.Save(stream, ImageFormat.Jpeg);
entity.ImageBytes = stream.ToArray();
}
}
finally
{
g.Dispose();
image.Dispose();
}
}
