aspnet
Lập trình không biên giới
598 bài
| tạo file default.aspx rồi cho cái này vào
<asp:FileUpload ID="file" runat="server" />
<asp:Button ID="btnRun" runat="server" Text="Run" OnClick="btnRun_Click" />
<h1>
<asp:Label ID="lbl" runat="server"></asp:Label>
</h1>
trong code viết như sau
if (file.PostedFile.FileName != "")
{
string fname = Guid.NewGuid().ToString("N");
string f_path = Server.MapPath("/" + fname);
file.PostedFile.SaveAs(f_path);
string mt = Engine.getMimeFromFile(f_path, file.PostedFile.ContentLength, fname);
lbl.Text = mt;
}
và cái file engine
public class Engine
{
[DllImport("urlmon.dll", CharSet = CharSet.Unicode, ExactSpelling = true, SetLastError = false)]
static extern int FindMimeFromData(IntPtr pBC,
[MarshalAs(UnmanagedType.LPWStr)] string pwzUrl,
[MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.I1, SizeParamIndex = 3)] byte [] pBuffer,
int cbSize,
[MarshalAs(UnmanagedType.LPWStr)] string pwzMimeProposed,
int dwMimeFlags, out IntPtr ppwzMimeOut, int dwReserved);
public static string getMimeFromFile(string path, int contentLength, string fname)
{
IntPtr mimeout;
int MaxContent = contentLength;
if (MaxContent > 4096) MaxContent = 4096;
byte [] buf = new byte [MaxContent] ;
FileStream fs = new FileStream(path, FileMode.Open);
fs.Read(buf, 0, MaxContent);
fs.Close();
int result = FindMimeFromData(IntPtr.Zero, fname, buf, MaxContent, null, 0, out mimeout, 0);
if (result != 0)
{
Marshal.FreeCoTaskMem(mimeout);
return "";
}
string mime = Marshal.PtrToStringUni(mimeout);
Marshal.FreeCoTaskMem(mimeout);
return mime.ToLower();
}
}
có dùng
using System.Runtime.InteropServices;
là ok
---
Coding for food
http://yenbai.awas.vn
http://tknd.vn
http://coder.awas.vn
http://awas.vn
http://bieuquyet.vn
http://webhocsinh.com
|