测试代码
byte[] imgb; using (FileStream fs = new FileStream(@"D:\favicon.ico", FileMode.Open)) { imgb = new byte[fs.Length]; fs.Read(imgb, 0, (int)fs.Length); } string imgtype = imgb.GetImageType();
扩展方法实现
public static string GetImageType(this byte[] imgb) { //JPEG/JPG - 文件头标识 (2 bytes): $ff, $d8 (SOI) (JPEG 文件标识) - 文件结束标识 (2 bytes): $ff, $d9 (EOI) if (imgb[0]== 0xff && imgb[1] == 0xd8 && imgb[imgb.Length-2] == 0xff && imgb[imgb.Length - 1] == 0xd9 ) { return "JPEG/JPG"; } //TGA - 未压缩的前5字节 00 00 02 00 00 - RLE压缩的前5字节 00 00 10 00 00 if ((imgb[0] == 0 && imgb[1] == 0 && imgb[2] == 2 && imgb[3] == 0 && imgb[4] == 0) || (imgb[0] == 0 && imgb[1] == 0 && imgb[2] == 10 && imgb[3] == 0 && imgb[4] == 0)) { return "TGA"; } //PNG - 文件头标识 (8 bytes) 89 50 4E 47 0D 0A 1A 0A if (imgb[0] == 0x89 && imgb[1] == 0x50 && imgb[2] == 0x4e && imgb[3] == 0x47 && imgb[4] == 0x0d && imgb[5] == 0x0a && imgb[6] == 0x1a && imgb[7] == 0x0a) { return "PNG"; } //GIF - 文件头标识 (6 bytes) 47 49 46 38 39(37) 61 G I F 8 9 (7) a if (imgb[0] == 0x47 && imgb[1] == 0x49 && imgb[2] == 0x46 && imgb[3] == 0x38 && (imgb[4] ==0x39 || imgb[4] == 0x37) && imgb[5] == 0x61) { return "GIF"; } //BMP - 文件头标识 (2 bytes) 42 4D B M if (imgb[0] == 0x42 && imgb[1] == 0x4d ) { return "BMP"; } //PCX - 文件头标识 (1 bytes) 0A if (imgb[0] == 0x0a) { return "PCX"; } ///TIFF - 文件头标识 (2 bytes) 4D 4D 或 49 49 if ((imgb[0] == 0x4d && imgb[1] == 0x4d)|| (imgb[0] == 0x49 && imgb[1] == 0x49)) { return "TIFF"; } //ICO - 文件头标识 (8 bytes) 00 00 01 00 01 00 30 30 if (imgb[0] == 0x00 && imgb[1] == 0x00 && imgb[2] == 0x01 && imgb[3] == 0x00 && imgb[4] == 0x01 && imgb[5] == 0x00 && imgb[6] == 0x30 && imgb[7] == 0x30) { return "ICO"; } //CUR - 文件头标识 (8 bytes) 00 00 02 00 01 00 20 20 if (imgb[0] == 0x00 && imgb[1] == 0x00 && imgb[2] == 0x02 && imgb[3] == 0x00 && imgb[4] == 0x01 && imgb[5] == 0x00 && imgb[6] == 0x20 && imgb[7] == 0x20) { return "CUR"; } ///IFF - 文件头标识 (4 bytes) 46 4F 52 4D F O R M if (imgb[0] == 0x46 && imgb[1] == 0x4f && imgb[2] == 0x52 && imgb[3] == 0x4d) { return "IFF"; } //ANI - 文件头标识 (4 bytes) 52 49 46 46 R I F F if (imgb[0] == 0x52 && imgb[1] == 0x49 && imgb[2] == 0x46 && imgb[3] == 0x46) { return "IFF"; } return string.Empty; }
时间: 2024-11-05 15:56:56