Convert Char into AnsiChar or WideChar (Delphi)

2
votes

I'm upgrading a very old (10+ years) application to the latest Delphi XE. There are a number of errors I keep getting like 

Incompatible types: 'WideChar' and 'AnsiChar'

I have been just casting the char to the right type: ex. AWideChar = WideChar(fncReturnsChar);

Is this going to cause problems?

3
delphiunicodedelphi-xewidechar
On XE you cannot get the error message that you report since WideChar and Char are one and the same. I think you need to show some more code. - David Heffernan
Also, have you read the various tutorials on how to switch to Unicode Delphi? In particular I believe there is a very useful white paper by Marco Cantu. - David Heffernan
@David The error I mentioned wasn't cut and paste, I meant to say 'AnsiChar' instead of 'Char'. Thanks to the link Mikael posted I've read the witepaper and understand now that WideChar=Char. I have to thank you for your help too, so here's an upvote. - Daisetsu

3 Answers

6
votes

There might be problems in there for you. Here is a white paper on Unicode in Delphi by Marco Cantù.

http://edn.embarcadero.com/article/38980

2
votes
var
    Initials: String[10];
    FullName: String;

begin

    Initials[1] := FullName[1]; // Error here after Delphi 2009

end;

The problem is that String[10] is the type of AnsiString in later Delphi versions. You are going to assign a Unicode character to an ANSI character in the above code.

The solution is a simple type cast:

Initials[1] := AnsiChar(FullName[1]);

Please refer the document recommended in Mikael Eriksson's answer. That is essential.

2
votes
var
  C : Char;
  AC : AnsiChar;
begin
  AC := '1';
  // C := AC; Delphi does not know how to convert ANSI to Unicode without a codepage
  C := String(AC)[1]; // Any way we can do that by default ANSI decoder
end.