windows - USB-Printer printing progress information -

i need write program finds connected usb-printers of windows pc , send file selected printer list. these 2 points no problem , work pretty fine

first point

        var printerquery = new managementobjectsearcher("select * win32_printer");         = 1;         foreach (var printer in printerquery.get())         {             var name = printer.getpropertyvalue("name");             var status = printer.getpropertyvalue("status");             var isdefault = printer.getpropertyvalue("default");             var isnetworkprinter = printer.getpropertyvalue("network");             var portname = printer.getpropertyvalue("portname");             bool connected = (bool)printer.getpropertyvalue("workoffline");             var caption = printer.getpropertyvalue("caption");              string s = "name: " + name;             string nbr = "";             if (i.tostring().length < 2) nbr = "0";             nbr += i.tostring();             listboxusbinfo.items.add(nbr + ": " + s);             listboxusbinfo.items.add("      status: " + status);             listboxusbinfo.items.add("      default: " + isdefault);             listboxusbinfo.items.add("      network: " + isnetworkprinter);             listboxusbinfo.items.add("      portname: " + portname);             if ( connected) listboxusbinfo.items.add("      connected: true");             if (!connected) listboxusbinfo.items.add("      connected: false");             listboxusbinfo.items.add("      caption: " + caption);              i++;         } 

second point

is quite easy:

the class "rawprinterhelper" known in forum, think

rawprinterhelper.sendfiletoprinter("printername", "filename"); 

but problem.

i must print large files (more 100.000 pages) , operator wants see, how many pages printed. possible information? example every 3 seconds, can display @ on screen.

here more information rawprinterhelper class. contains no callback. what must define callback function?

public class rawprinterhelper {     // structure , api declarions:     [structlayout(layoutkind.sequential, charset = charset.ansi)]     public class docinfoa     {         [marshalas(unmanagedtype.lpstr)]         public string pdocname;         [marshalas(unmanagedtype.lpstr)]         public string poutputfile;         [marshalas(unmanagedtype.lpstr)]         public string pdatatype;     }     [dllimport("winspool.drv", entrypoint = "openprintera", setlasterror = true, charset = charset.ansi, exactspelling = true, callingconvention = callingconvention.stdcall)]     public static extern bool openprinter([marshalas(unmanagedtype.lpstr)] string szprinter, out intptr hprinter, intptr pd);      [dllimport("winspool.drv", entrypoint = "closeprinter", setlasterror = true, exactspelling = true, callingconvention = callingconvention.stdcall)]     public static extern bool closeprinter(intptr hprinter);      [dllimport("winspool.drv", entrypoint = "startdocprintera", setlasterror = true, charset = charset.ansi, exactspelling = true, callingconvention = callingconvention.stdcall)]     public static extern bool startdocprinter(intptr hprinter, int32 level, [in, marshalas(unmanagedtype.lpstruct)] docinfoa di);      [dllimport("winspool.drv", entrypoint = "enddocprinter", setlasterror = true, exactspelling = true, callingconvention = callingconvention.stdcall)]     public static extern bool enddocprinter(intptr hprinter);      [dllimport("winspool.drv", entrypoint = "startpageprinter", setlasterror = true, exactspelling = true, callingconvention = callingconvention.stdcall)]     public static extern bool startpageprinter(intptr hprinter);      [dllimport("winspool.drv", entrypoint = "endpageprinter", setlasterror = true, exactspelling = true, callingconvention = callingconvention.stdcall)]     public static extern bool endpageprinter(intptr hprinter);      [dllimport("winspool.drv", entrypoint = "writeprinter", setlasterror = true, exactspelling = true, callingconvention = callingconvention.stdcall)]     public static extern bool writeprinter(intptr hprinter, intptr pbytes, int32 dwcount, out int32 dwwritten);      // sendbytestoprinter()     // when function given printer name , unmanaged array     // of bytes, function sends bytes print queue.     // returns true on success, false on failure.     public static bool sendbytestoprinter(string szprintername, intptr pbytes, int32 dwcount)     {         int32 dwerror = 0, dwwritten = 0;         intptr hprinter = new intptr(0);         docinfoa di = new docinfoa();         bool bsuccess = false; // assume failure unless succeed.          di.pdocname = "my c#.net raw document";         di.pdatatype = "raw";          // open printer.         if (openprinter(szprintername.normalize(), out hprinter, intptr.zero))         {             // start document.             if (startdocprinter(hprinter, 1, di))             {                 // start page.                 if (startpageprinter(hprinter))                 {                     // write bytes.                     bsuccess = writeprinter(hprinter, pbytes, dwcount, out dwwritten);                     endpageprinter(hprinter);                 }                 enddocprinter(hprinter);             }             closeprinter(hprinter);         }         // if did not succeed, getlasterror may give more information         // why not.         if (bsuccess == false)         {             dwerror = marshal.getlastwin32error();         }         return bsuccess;     }      public static bool sendfiletoprinter(string szprintername, string szfilename)     {         // open file.         filestream fs = new filestream(szfilename, filemode.open);         // create binaryreader on file.         binaryreader br = new binaryreader(fs);         // dim array of bytes big enough hold file's contents.         byte[] bytes = new byte[fs.length];         bool bsuccess = false;         // unmanaged pointer.         intptr punmanagedbytes = new intptr(0);         int nlength;          nlength = convert.toint32(fs.length);         // read contents of file array.         bytes = br.readbytes(nlength);         // allocate unmanaged memory bytes.         punmanagedbytes = marshal.alloccotaskmem(nlength);         // copy managed byte array unmanaged array.         marshal.copy(bytes, 0, punmanagedbytes, nlength);         // send unmanaged bytes printer.         bsuccess = sendbytestoprinter(szprintername, punmanagedbytes, nlength);         // free unmanaged memory allocated earlier.         marshal.freecotaskmem(punmanagedbytes);         fs.close();         return bsuccess;     }      public static bool sendstringtoprinter(string szprintername, string szstring)     {         intptr pbytes;         int32 dwcount;         // how many characters in string?         dwcount = szstring.length;         // assume printer expecting ansi text, , convert         // string ansi text.         pbytes = marshal.stringtocotaskmemansi(szstring);         // send converted ansi string printer.         sendbytestoprinter(szprintername, pbytes, dwcount);         marshal.freecotaskmem(pbytes);         return true;     } } // public class rawprinterhelper