C#验证码

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/// <summary>
///验证码
/// </summary>
public class VerifyCode
{
    /// <summary>
    /// 验证码字体大小 ( 为了显示扭曲效果，默认 40 像素，可以自行修改 )
    /// </summary>
    int FontSize = 40;
 
    /// <summary>
    /// 文字间距
    /// </summary>
    int Padding = 3;
 
    /// <summary>
    /// 自定义背景色 ( 默认白色 )
    /// </summary>
    Color BackgroundColor = Color.White;
 
    /// <summary>
    /// 自定义随机颜色数组
    /// </summary>
    Color[] Colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };
    /// <summary>
    /// 自定义字体数组
    /// </summary>
    string[] Fonts = { "Arial", "Georgia", "courier new" };
 
 
    /// <summary>
    /// 自定义随机码字符串序列 ( 使用逗号分隔 )
    /// </summary>
    string CodeSerial = "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
 
    #region 产生波形滤镜效果
    private const double PI2 = 6.283185307179586476925286766559;
    /// <summary>
    /// 正弦曲线 Wave 扭曲图片（ Edit By 51aspx.com ）
    /// </summary>
    /// <param name="srcBmp"> 图片路径 </param>
    /// <param name="bXDir"> 如果扭曲则选择为 True </param>
    /// <param name="dMultValue"> 波形的幅度倍数，越大扭曲的程度越高，一般为 3 </param>
    /// <param name="dPhase"> 波形的起始相位，取值区间 [0-2*PI) </param>
    /// <returns></returns>
    public byte[] TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)
    {
        using (Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height))
        {
            // 将位图背景填充为白色
            using (Graphics graph = Graphics.FromImage(destBmp))
            {
                graph.FillRectangle(new SolidBrush(Color.White), 0, 0, destBmp.Width, destBmp.Height);
                double dBaseAxisLen = bXDir ? (double)destBmp.Height : (double)destBmp.Width;
                for (int i = 0; i < destBmp.Width; i++)
                {
                    for (int j = 0; j < destBmp.Height; j++)
                    {
                        double dx = (bXDir ? (PI2 * (double)j) / dBaseAxisLen : (PI2 * (double)i) / dBaseAxisLen) + dPhase;
                        double dy = Math.Sin(dx);
                        // 取得当前点的颜色 
                        int nOldX = bXDir ? i + (int)(dy * dMultValue) : i;
                        int nOldY = bXDir ? j : j + (int)(dy * dMultValue);
                        Color color = srcBmp.GetPixel(i, j);
                        if (nOldX >= 0 && nOldX < destBmp.Width && nOldY >= 0 && nOldY < destBmp.Height)
                        {
                            destBmp.SetPixel(nOldX, nOldY, color);
                        }
                    }
                }
            }
            using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
            {
                destBmp.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
                return ms.GetBuffer();
            }
        }
    }
    #endregion
    #region 生成校验码图片
    public byte[] CreateImageCode(int codeLen = 6)
    {
        string code = CreateVerifyCode(codeLen);
        int fSize = FontSize;
        int fWidth = fSize + Padding;
        int imageWidth = (int)(code.Length * fWidth) + 4 + Padding * 2;
        int imageHeight = fSize * 2 + Padding;
        using (Bitmap image = new Bitmap(imageWidth, imageHeight))
        {
            using (Graphics g = Graphics.FromImage(image))
            {
                g.Clear(BackgroundColor);
                Random rand = new Random();
                int left = 0, top = 0;
                int n1 = (imageHeight - FontSize - Padding * 2);
                int n2 = n1 / 4;
                Font f;
                Brush b;
                int cindex, findex;
                // 随机字体和颜色的验证码字符
                for (int i = 0; i < code.Length; i++)
                {
                    cindex = rand.Next(Colors.Length - 1);
                    findex = rand.Next(Fonts.Length - 1);
 
                    f = new Font(Fonts[findex], fSize, FontStyle.Bold);
                    b = new SolidBrush(Colors[cindex]);
                    if (i % 2 == 1)
                    {
                        top = n2 * 2;
                    }
                    else
                    {
                        top = n2;
                    }
                    left = i * fWidth;
                    g.DrawString(code.Substring(i, 1), f, b, left, top);
                }
            }
            // 产生波形
            return TwistImage(image, true, 8, 4);
        }
    }
    #endregion 
    #region 生成随机字符码
    public string CreateVerifyCode(int codeLen)
    {
        string[] arr = CodeSerial.Split(',');
        string code = "";
        Random rand = new Random(unchecked((int)DateTime.Now.Ticks));
        for (int i = 0; i < codeLen; i++)
        {
            code += arr[rand.Next(0, arr.Length - 1)];
        }
        return code;
    }
    #endregion
}