把缓冲区中指定数目的字符转大写

 

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' ;
  CharUpperBuff(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' ;
  CharUpperBuff(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 := CharUpperBuff(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' ;
  CharUpperBuff(@str[ 1 ], Length(str));
  ShowMessage(str); {ABCDEFG}
end;

end.