Convert Char into AnsiChar or WideChar (Delphi)

问题

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?

回答1:

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

回答2:

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.

回答3:

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.

来源：https://stackoverflow.com/questions/4997142/convert-char-into-ansichar-or-widechar-delphi