Code to Check filte Type by reading its Content

public bool isPDFDocument(string file)
{

string mimeout = "";

int MaxContent = 0;

Stream fs = null;

byte[] buf = null;

int result = 0;

try
{

HttpWebRequest request = (HttpWebRequest)

WebRequest.Create(file);

HttpWebResponse response = (HttpWebResponse)
request.GetResponse();
fs = response.GetResponseStream();

//MaxContent = response.ContentLength;

if (response.ContentLength > 4096)
{
MaxContent = 4096;
}

else
{
MaxContent =
Convert.ToInt32(response.ContentLength);
}

buf =
new byte[MaxContent + 1];
fs.Read(buf, 0, MaxContent);
fs.Close();
result = FindMimeFromData(
IntPtr.Zero, null, buf, MaxContent, null, 0, ref mimeout, 0);

if (mimeout != null && (mimeout.ToLower().Contains("pdf") || mimeout.ToLower().Contains("tif")))
{

return true;
}

else
{

return false;
}
}

catch (Exception ex)
{

return false;
}
}