You beat me to it. I was going to say the same, that I'm interested in these answers also. I have customers all over the world and just recently the display of Chinese characters was desired in a non-Chinese speaking country. So eventually I'll have to convert to Unicode.
Ross. -----Original Message----- From: delphi-boun...@delphi.org.nz [mailto:delphi-boun...@delphi.org.nz] On Behalf Of David Brennan Sent: Tuesday, 23 November 2010 1:27 PM To: 'NZ Borland Developers Group - Delphi List' Subject: Re: [DUG] Upgrading to XE - Unicode strings questions Just thought I would chime in that I'm really interested in the answers to these questions too (Unicode being something we are also a bit apprehensive of). -----Original Message----- From: delphi-boun...@delphi.org.nz [mailto:delphi-boun...@delphi.org.nz] On Behalf Of John Bird Sent: Tuesday, 23 November 2010 1:04 p.m. To: NZ Borland Developers Group - Delphi List Subject: Re: [DUG] Upgrading to XE - Unicode strings questions Thanks for the references, so I can answer most of the questions now. Here is what I understand so far, if anyone has anything to add this will be useful! Extra question: It looks like code like for i:=1 to length(string1) do begin DoSomethingWithOneChar(string1[i]); end; cannot be used reliably. The problems are that length(string1) looks like it cannot be safely used - as unicode characters may include 2 codepoints and length(string1) highlights that there is a difference between the number of unicode characters in a string and the number of codepoints. Still figuring out what is the best practice here, as I have quite a lot of string routines. Should be be OK as long as the unicode text actually is ASCII. Q2 – With XE do the .pas and .dfm files become unicode text and hence cannot be read by earlier Delphi, eg D2007 any more? Answer - Is a project option from what I have read?, yes not portable if unicode. Q3 – I do a lot of reading ascii data files, and writing back. Using mainly TFilestream and stringlists. Does this in general mean I will need to use file variables declared as Ansichar and AnsiString instead of Char and String? (I would prefer to use the standard VCL where possible) If I have variables as1:Ansistring; s2:string; Q4 – if I do s2:=as1 does this convert ansistrings to unicode? Answer - yes, there are performance issues to watch out for if conversion happens a lot. Q5 – if I do as1:=s2 does this convert a unicode string to ansistring? (otherwise how do I do this?) Answer - yes, there are performance issues to watch out for if conversion happens a lot. Q6 – I understand any code like char1:=string1[i]; if char1 in [‘a’..’z’] then begin message:=string[i]+’ - character is lowercase’; end will break, as ansi characters are ordinal (less than 256 or 512) and set comparisons ['a'..'z'] or ['a','b','c'] can be used, this set code cannot be used for unicode characters. What is the replacement? Answer - There is CharInSet call and numerous extra housekeeping functions added in TCharacter. Q7 – do literals like #13#10 still mean carriage return and linefeed? #9 means tab? if I have code like (logline string1 string2 are string) logline:=FormatDateTime(‘dd-mmm-yyyy hh:nn:ss’,now) + string1 + #13#10+#9 + string2; ShowMessage(logline); Button1.hint:=logline; writeln(f,logline); these work D5-D2007 - ie a 2 line messagebox text, 2 line hint, and 2 lines written to a log file. is this still going to work? do carriage returns/tabs/other control characters have to be defined differently, eg as constants? Answer - not figured out yet - anyone else know? Q8 – stringlist1.loadfromfile(‘Test1.txt’); what happens if this file is ascii text being read into a stringlist which is unicode strings. Answer - Default is Ascii text for loadfromfile and savetofile, use overloaded routines for Unicode Q9 - stringlist1.savetofile(‘Test1.txt’) presumably this is no longer ascii text. How do I save and read a stringlist to/from a file if it is to be Ansi text? Q10 – If there are complexities in Q8 and Q9 is there a TAnsiStringlist type (for ansistrings) as well as a unicode TStringlist type? (I use stringlists a lot) Answer - unicodestring lists can save to ascii or unicode files, so TAnsiStringlist not needed. Q11 – do inifiles become unicode too? Answer - looks like no? Not clear? Anyone else know? Q12 – does Windows Notepad open unicode text files correctly? or can it only be used on Ansi text files? Anyone know this? Q13 - It looks like most programmers editors read and write ascii and unicode encoding.....the one I use seems to distinguish between UTF-8 and unicode as well – what is the difference? Anyone know this? John _______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz Admin: http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: unsubscribe _______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz Admin: http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: unsubscribe _______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz Admin: http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: unsubscribe _______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz Admin: http://delphi.org.nz/mailman/listinfo/delphi Unsubscribe: send an email to delphi-requ...@delphi.org.nz with Subject: unsubscribe
