1 /*文件扩展名说明
2 * 255216 jpg
3 * 208207 doc xls ppt wps
4 * 8075 docx pptx xlsx zip
5 * 5150 txt
6 * 8297 rar
7 * 7790 exe
8 * 3780 pdf
9 *
10 * 4946/104116 txt
11 * 7173 gif
12 * 255216 jpg
13 * 13780 png
14 * 6677 bmp
15 * 239187 txt,aspx,asp,sql
16 * 208207 xls.doc.ppt
17 * 6063 xml
18 * 6033 htm,html
19 * 4742 js
20 * 8075 xlsx,zip,pptx,mmap,zip
21 * 8297 rar
22 * 01 accdb,mdb
23 * 7790 exe,dll
24 * 5666 psd
25 * 255254 rdp
26 * 10056 bt种子
27 * 64101 bat
28 * 4059 sgf
29 */
30
31 public static bool IsAllowedExtension(string hifile)
32 {
33
34 string[] extList = { "255216", "208207", "8075", "3780", "4946", "104116", "7173", "255216", "13780", "6677", "5150" };
35
36 System.IO.FileStream fs = new System.IO.FileStream(hifile, System.IO.FileMode.Open, System.IO.FileAccess.Read);
37 System.IO.BinaryReader r = new System.IO.BinaryReader(fs);
38 string fileclass = "";
39 //这里的位长要具体判断.
40 byte buffer;
41 try
42 {
43 buffer = r.ReadByte();
44 fileclass = buffer.ToString();
45 buffer = r.ReadByte();
46 fileclass += buffer.ToString();
47
48 }
49 catch
50 {
51
52 }
53 r.Close();
54 fs.Close();
55 if (extList.Contains(fileclass))
56 {
57 return true;
58 }
59 else
60 {
61 return false;
62 }
63
64 }