判断文件后缀

通过文件头判断文件类型、后辍

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string path = @"E:b55b319ebc4b745d931e035cefc1e178a82156f";
            using (FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read))
            {
                using (BinaryReader r = new BinaryReader(fs))
                {
                    string bx = "";
                    byte buffer;
                    try
                    {
                        buffer = r.ReadByte();
                        bx = buffer.ToString();
                        buffer = r.ReadByte();
                        bx += buffer.ToString();
                    }
                    catch (Exception exc)
                    {
                        Console.WriteLine(exc.Message);
                    }
                    Console.WriteLine(bx);
                    Console.ReadLine();
                }
            }
        }
    }
}

常见文件类型对应编码

        JPG = 255216,
        GIF = 7173,
        BMP = 6677,
        PNG = 13780,
        COM = 7790,
        EXE = 7790,
        DLL = 7790,
        RAR = 8297,
        ZIP = 8075,
        XML = 6063,
        HTML = 6033,
        ASPX = 239187,
        CS = 117115,
        JS = 119105,
        TXT = 210187,
        SQL = 255254,
        BAT = 64101,
        BTSEED = 10056,
        RDP = 255254,
        PSD = 5666,
        PDF = 3780,
        CHM = 7384,
        LOG = 70105,
        REG = 8269,
        HLP = 6395,
        DOC = 208207,
        XLS = 208207,
        DOCX = 208207,
        XLSX = 208207

参考资料：http://baike.baidu.com/link?url=ou1rjPoTKCnvIghdTdaL-QdSpgCaVm9qETOMoqBJxcj43N2OGgcyymH2-EfAj27ecuwQhasGBHXey9C-qC7bmK