SysUtils 中其他 PChar 函数: StrPas、StrNew、StrDispose、StrNextChar、StrFmt、StrLFmt、StrCharLength

//StrPas: 转换 PChar 为 string; 现在可以直接赋值, 很少用了.
var
p: PChar;
s: string;
begin
p := 'Delphi';
s := StrPas(p);
ShowMessage(s); {Delphi}
end;

//StrNew、StrDispose: 建立与销毁 PChar.
var
p: PChar;
begin
p := StrNew('Delphi');
ShowMessage(p); {Delphi}
StrDispose(p);
end;

//StrFmt、StrLFmt: 针对 PChar 的格式化函数
var
buf: array[0..255] of Char;
p: PChar;
begin
p := StrFmt(buf, '%d, %d', [123, MaxInt]);
ShowMessage(buf); {123, 2147483647}
ShowMessage(p);   {123, 2147483647}

p := StrLFmt(buf, 9, '%d, %d', [123, MaxInt]);
ShowMessage(buf); {123, 2147}
ShowMessage(p);   {123, 2147}
end;

//StrNextChar; 因为 PChar 支持加减运算, 这个函数很少用
var
p: PChar;
begin
p := '12345';
p := StrNextChar(p);
ShowMessage(p);      {2345}
end;

//StrCharLength: 一个 Char 的长度
var
p: PChar;
i: Integer;
begin
p := 'Delphi';
i := StrCharLength(p);
ShowMessage(IntToStr(i)); {1}
end;