编程实现QQ表情文件CFC格式

背景：最近闲来无事，也应论坛某会员要求，想做个QQ表情下载的站点。本来事情是很简单的，写个小小的CRUD也就可以了，但嘻哈呵嘿既然是个.Net程序员，当然要使用.Net来实现了。今天我们就用.Net来实现CFC ( custom face cab? ) 的表情格式的打包功能。

从这篇文章里我们得知了CFC的文件格式大概如下：

一个块有15个字段，如下

md5的字符串形式长度，4个字节
快捷键长度，4字节
表情名称长度，4字节
表情文件名长度，4字节
表情文件长度，4字节
微缩图文件名长度，4字节
微缩文件长度，4字节
表情文件帧数，4字节
图片md5的字符串形式
快捷键
表情名称
表情文件名
微缩图文件名
表情文件内容
微缩图内容
知道了格式就好办了，我们按步就班定义一个结构(struct)
 1    Struct#region Struct
 2    public struct FaceBlock
 3    {
 4        public uint MD5Length; //32
 5        public uint uintcutLength; //4
 6        public uint FaceNameLength; //4
 7        public uint FaceFileNameLength; //36 md5 + extension
 8        public uint FileLength;
 9        public uint ThumbnailFileNameLength; //41 md5 + fixed.bmp
10        public uint ThumbnailFileLength;
11        public uint FrameLength;
12        public string MD5;
13        public string uintcuts;
14        public string FaceName;
15        public string FaceFileName;
16        public string ThumbnailFileName;
17        public byte[] FaceData;
18        public byte[] ThumbnailData;
19
20        public static FaceBlock FromImage(string file)
21        {
22            return FaceHelper.GetFaceBlockFromImage(file);
23        }
24
25        byte[] GetBytes(uint value)
26        {
27            byte[] bt = BitConverter.GetBytes(value);
28            List<byte> bytes = new List<byte>();
29            bytes.AddRange(bt);
30            if (bytes.Count < 4)
31            {
32                int l = 4 - bytes.Count;
33                for (int i = 0; i < l; i++)
34                    bytes.Add((byte)0);
35            }
36            return bytes.ToArray();
37        }
38
39        public byte[] ToBytes()
40        {
41            List<byte> bytes = new List<byte>();
42            Encoding e = Encoding.ASCII;
43            bytes.AddRange(GetBytes(MD5Length));
44            bytes.AddRange(GetBytes(uintcutLength));
45            bytes.AddRange(GetBytes(FaceNameLength));
46            bytes.AddRange(GetBytes(FaceFileNameLength));
47            bytes.AddRange(GetBytes(FileLength));
48            bytes.AddRange(GetBytes(ThumbnailFileNameLength));
49            bytes.AddRange(GetBytes(ThumbnailFileLength));
50            bytes.AddRange(GetBytes(FrameLength));
51
52            bytes.AddRange(e.GetBytes(MD5));
53            bytes.AddRange(e.GetBytes(uintcuts));
54            bytes.AddRange(e.GetBytes(FaceName));
55            bytes.AddRange(e.GetBytes(FaceFileName));
56            bytes.AddRange(e.GetBytes(ThumbnailFileName));
57
58            bytes.AddRange(FaceData);
59            bytes.AddRange(ThumbnailData);
60
61            return bytes.ToArray();
62        }
63    }
64    #endregion其中含有两方法，一个是从文件得到一个此结构的静态方法，另一个是将此结构转化为byte数组。

我们再建一个类，命名为：FaceHelper
代码如下：
    public class FaceHelper
    {
        internal static FaceBlock GetFaceBlockFromImage(string file)
        {
            FaceBlock fb = new FaceBlock();
            //打开文件流  
            FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read);
            //获取图像
            Image img = Image.FromStream(fs);
            //获得一个20*20的缩略图
            Image thumbnail = img.GetThumbnailImage(20, 20, null, IntPtr.Zero);
            MemoryStream ms = new MemoryStream();
            //将缩图图转化数byte数组
            thumbnail.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp);
            byte[] thumbnailData = ms.ToArray();
            ms.Close();
            ms.Dispose();
            thumbnail.Dispose();

            //得到一个唯一的MD5字符串
            string md5 = GetMD5(fs);
            //文件名，格式为:md5 + 扩展名
            string fileName = string.Format("{0}{1}", md5, Path.GetExtension(file));
            //缩略图文件名，格式为：md5 + fixed.bmp
            string thumbnailName = string.Format("{0}fixed.bmp", md5);
            //随机设置一个快捷键
            string uintcuts = "qq.5inet.net_" + RandomNum(6);
            fs.Close();
            fs.Dispose();

            //取得总的帧数
System.Drawing.Imaging.FrameDimension fd = System.Drawing.Imaging.FrameDimension.Resolution;
            int frameCount = img.FrameDimensionsList.Length;
            img.Dispose();

            fb.MD5 = md5;
            fb.MD5Length = (uint)md5.Length;
            fb.uintcuts = uintcuts;
            fb.uintcutLength = (uint)uintcuts.Length;
            fb.FaceName = uintcuts;
            fb.FaceNameLength = (uint)uintcuts.Length;
            fb.FaceFileName = fileName;
            fb.FaceFileNameLength = (uint)fileName.Length;
            fb.ThumbnailFileName = thumbnailName;
            fb.ThumbnailFileNameLength = (uint)thumbnailName.Length;
            fb.FaceData = File.ReadAllBytes(file);
            fb.FileLength = (uint)fb.FaceData.Length;
            fb.ThumbnailData = thumbnailData;
            fb.ThumbnailFileLength = (uint)thumbnailData.Length;
            fb.FrameLength = (uint)frameCount;

            return fb;
        }

        Helper#region Helper
        //随机方法
        internal static string RandomNum(int n) //
        {
            string strchar = "0,1,2,3,4,5,6,7,8,9";
            string[] VcArray = strchar.Split(',');
            string VNum = "";//由于字符串很短，F77pclw,c络G|?,业,e'b就不用StringBuilder了
            int temp = -1;    //记录上次随机数值，尽量避免产生几个一样的随机数
            //采用一个简单的算法以保证生成随机数的不同
            Random rand = new Random();
            for (int i = 1; i < n + 1; i++)
            {
                if (temp != -1)
                {
                    rand = new Random(i * temp * unchecked((int)

                 DateTime.Now.Ticks));
                }
                //int t =  rand.Next(35) ;
                int t = rand.Next(10);
                if (temp != -1 && temp == t)
                {
                    return RandomNum(n);
                }
                temp = t;
                VNum += VcArray[t];
            }
            return VNum;//返回生成的随机数
        }

        //从文件名获得MD5
        internal static string GetMD5(FileStream fs)
        {
            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
            byte[] md5byte = md5.ComputeHash(fs);
            string str = string.Empty;
            int i, j;
            foreach (byte b in md5byte)
            {
                i = Convert.ToInt32(b);
                j = i >> 4;
                str += (Convert.ToString(j, 16));
                j = ((i << 4) & 0x00ff) >> 4;
                str += (Convert.ToString(j, 16));
            }

            return str.ToUpper();
        }
        #endregion

        //从一个目录生成一个CFC文件集合
        public static void
BuildCFCFileFromDirectory(string directory)
        {
            List<byte> bytes = new List<byte>();
            foreach (string file in Directory.GetFiles(directory))
            {
                if (!IsImageFile(file))
                    continue;

                bytes.AddRange(FaceBlock.FromImage(file).ToBytes());
            }

            string fName = Path.Combine(directory, Path.GetDirectoryName(directory) + ".cfc");
            FileStream fs = File.Create(fName);
            fs.Write(bytes.ToArray(), 0, bytes.Count);
            fs.Close();
        }

        //判断是否为图像文件，方法比较简陋。
        private static bool IsImageFile(string file)
        {
            List<string> validExt = new List<string>(new string[]{
                ".bmp",
                ".jpg",
                ".jpeg",
                ".gif",
                ".png",
            });

            return validExt.Contains(Path.GetExtension(file).ToLower());
        }
    }
好，有了上面的方法，我们就可以调用了。
调用方法实在是有些简单。

FaceHelper.BuildCFCFileFromDirectory(Server.MapPath("~/img/"));
这样就OK了，现在去你的网站根目录下看看，有没有一个img.cfc的文件呢？再双击一下，是不是将img目录下的文件全部导入到QQ表情里了呢？ enjoy coding!