WinAPI 字符及字符串函数(2): CharLowerBuff - 把缓冲区中指定数目的字符转小写
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
TForm1 = class(TForm)
Button1: TButton;
Button2: TButton;
Button3: TButton;
Button4: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
procedure Button4Click(Sender: TObject);

end;

var
Form1: TForm1;

implementation

{$R *.dfm}

{对字符数组, 全部转换}
procedure TForm1.Button1Click(Sender: TObject);
var
buf: array[0..6] of Char;
begin
buf := 'ABCDEFG';
CharLowerBuff(buf, Length(buf));

ShowMessage(buf); {abcdefg}
end;

{只转换前 3}
procedure TForm1.Button2Click(Sender: TObject);
var
buf: array[0..6] of Char;
begin
buf := 'ABCDEFG';
CharLowerBuff(buf, 3);

ShowMessage(buf); {abcDEFG}
end;

{返回值}
procedure TForm1.Button3Click(Sender: TObject);
var
buf: array[0..6] of Char;
num: Integer;
begin
buf := 'ABCDEFG';
num := CharLowerBuff(buf, 4);

ShowMessageFmt('%s, %d', [string(buf), num]); {abcdEFG, 4}
end;

{对字符串}
procedure TForm1.Button4Click(Sender: TObject);
var
str: string;
begin
str := 'ABCDEFG';
CharLowerBuff(@str[1], Length(str));
ShowMessage(str); {abcdefg}
end;

end.