C#获取指定PDF文件页数的方法

using System;using System.IO;using System.Text.RegularExpressions;using System.Windows.Forms;namespace RobvanderWoude{ class PDFPageCount {  static int Main( string[] args )  {   #region Get help   if ( args.Length == 0 )   {    ShowHelp( );    return 0;   }   foreach ( string arg in args )   {    if ( arg == "/?" || arg == "-?" || arg.ToLower( ) == "--help" )    {     ShowHelp( );     return 0;    }   }   #endregion   int errors = 0;   foreach ( string arg in args )   {    try    {     Regex regexp = new Regex( @"^(.*)//([^//]+/.pdf)$", RegexOptions.IgnoreCase );     if ( regexp.IsMatch( arg ) )     {      // Match means the filespec has a valid format (i.e. *.pdf)      string[] matches = regexp.Split( arg );      string folder = matches[1];      string filespec = matches[2];      if ( Directory.Exists( folder ) )      {       // Folder exists, check for matching files       string[] fileList = Directory.GetFiles( folder, filespec );       if ( fileList.Length == 0 )       {        // No matching files in this folder        ShowError( "ERROR: No files matching /"{0}/" were found in /"{1}/"", filespec, folder );        errors += 1;       }       else       {        // Iterate through list of matching files        foreach ( string file in fileList )        {         int pagecount = PageCount( file );         if ( pagecount == -1 )         {          // Just increase the error count, the PageCount( )          // procedure already wrote an error message to screen          errors += 1;         }         else         {          // No pages means there is a problem with the file          if ( pagecount == 0 )          {           Console.ForegroundColor = ConsoleColor.Red;           errors += 1;          }          // Display the formated result on screen          Console.WriteLine( "{0,4} {1,-10} {2}", pagecount.ToString( ), ( pagecount == 1 ? "page" : "pages" ), file );          if ( pagecount == 0 )          {           Console.ForegroundColor = ConsoleColor.Gray;          }         }        }       }      }      else      {       // Folder doesn't exist       ShowError( "ERROR: Folder /"{0}/" not found", folder );       errors += 1;      }     }     else     {      // No match for the regular expression means the filespec was invalid      ShowError( "ERROR: Invalid filespec /"{0}/", please specify PDF files only", arg );      errors += 1;     }    }    catch ( Exception e )    {     // All other errors: display an error message and then continue     ShowError( "ERROR: {0}", e.Message );     errors += 1;    }   }   if ( errors != 0 )   {    ShowError( "    {0} finished with {1} error{2}", GetExeName( ), errors.ToString( ), ( errors == 1 ? "" : "s" ) );   }   return errors;  }  static string GetExeName( )  {   string exe = Application.ExecutablePath.ToString( );   Regex regexp = new Regex( @"//([^//]+)$" );   return regexp.Split( exe )[1];  }  static int PageCount( string filename )  {   Regex regexp = new Regex( @"/.pdf$", RegexOptions.IgnoreCase );   if ( regexp.IsMatch( filename ) )   {    try    {     FileStream fs = new FileStream( filename, FileMode.Open, FileAccess.Read );     StreamReader sr = new StreamReader( fs );     string pdfText = sr.ReadToEnd( );     regexp = new Regex( @"/Type/s*/Page[^s]" );     MatchCollection matches = regexp.Matches( pdfText );     return matches.Count;    }    catch ( Exception e )    {     ShowError( "ERROR: {0} ({1})", e.Message, filename );     return -1;    }   }   else   {    ShowError( "ERROR: {0} is not a PDF file", filename );    return -1;   }  }  static void ShowError( string message, string param1, string param2 = "", string param3 = "" )  {   Console.Error.WriteLine( );   Console.ForegroundColor = ConsoleColor.Red;   Console.Error.WriteLine( message, param1, param2, param3 );   Console.ForegroundColor = ConsoleColor.Gray;   Console.Error.WriteLine( );  }  #region Display help text  static void ShowHelp( )  {   Console.Error.WriteLine( );   Console.Error.WriteLine( "{0}, Version 1.02", GetExeName( ) );   Console.Error.WriteLine( "Return the page count for the specified PDF file(s)" );   Console.Error.WriteLine( );   Console.Error.WriteLine( "Usage: {0} filespec [ filespec [ filespec [ ... ] ] ]", GetExeName( ).ToUpper( ) );   Console.Error.WriteLine( );   Console.Error.WriteLine( "Where: /"filespec/"  is a file specification for the PDF file(s) to" );   Console.Error.WriteLine( "       be listed (wildcards * and ? are allowed)" );   Console.Error.WriteLine( );   Console.Error.WriteLine( "Note:  The program's return code equals the number of errors encountered." );   Console.Error.WriteLine( );   Console.Error.WriteLine( "Written by Rob van der Woude" );  }  #endregion }}