#region 获取PDF文件的页数private int BytesLastIndexOf(Byte[] buffer, int length, string Search){if (buffer == null)return -1;if (buffer.Length <= 0)return -1;byte[] SearchBytes = Encoding.Default.GetBytes(Search.ToUpper());for (int i = length - SearchBytes.Length; i >= 0; i--){bool bFound = true;for (int j = 0; j < SearchBytes.Length; j++){if (ByteUpper(buffer[i + j]) != SearchBytes[j]){bFound = false;break;}}if (bFound)return i;}return -1;}private byte ByteUpper(byte byteValue){char charValue = Convert.ToChar(byteValue);if (charValue < 'a' || charValue > 'z')return byteValue;elsereturn Convert.ToByte(byteValue - 32);}/// <summary>/// 获取pdf文件的页数/// </summary>public int GetPDFPageCount(string path) //获取pdf文件的页数
        {path = HttpContext.Current.Server.MapPath(path);byte[] buffer = File.ReadAllBytes(path);int length = buffer.Length;if (buffer == null)return -1;if (buffer.Length <= 0)return -1;try{//Sample//      29 0 obj//      <</Count 9//      Type /Pagesint i = 0;int nPos = BytesLastIndexOf(buffer, length, "/Type/Pages");if (nPos == -1)return -1;string pageCount = null;for (i = nPos; i < length - 10; i++){if (buffer[i] == '/' && buffer[i + 1] == 'C' && buffer[i + 2] == 'o' && buffer[i + 3] == 'u' && buffer[i + 4] == 'n' && buffer[i + 5] == 't'){int j = i + 3;while (buffer[j] != '/' && buffer[j] != '>')j++;pageCount = Encoding.Default.GetString(buffer, i, j - i);break;}}if (pageCount == null)return -1;int n = pageCount.IndexOf("Count");if (n > 0){pageCount = pageCount.Substring(n + 5).Trim();for (i = pageCount.Length - 1; i >= 0; i--){if (pageCount[i] >= '0' && pageCount[i] <= '9'){return int.Parse(pageCount.Substring(0, i + 1));}}}return -1;}catch (Exception ex){return -1;}}#endregion