Delphi 2009 新增单元 Character[2]: IsLetter、IsUpper、IsLower、IsDigit、IsNumber

IsLetter: {是否是个字母; 范围 A..Z 与 a..z}
IsUpper:  {是否是个大写字母; 范围 A..Z}
IsLower:  {是否是个小写字母; 范围 a..z}
IsDigit:  {是否是个十进制数字; 范围 0..9}
IsNumber: {是否是个数字符号; 范围包括 0..9, 还有 ASCII 码中的 178、179、185、188、189、190 等}

测试代码:

---

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;
    Button5: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses Character;

{IsLetter: 是否是个字母}
procedure TForm1.Button1Click(Sender: TObject);
var
  b1,b2,b3: Boolean;
begin
  b1 := IsLetter('A'); {是}
  b2 := IsLetter('a'); {是}
  b3 := IsLetter('9'); {否}
  ShowMessageFmt('%s,%s,%s', [BoolToStr(b1,True),BoolToStr(b2,True),BoolToStr(b3,True)]);
  {True,True,False}

  b1 := IsLetter('D2009', 1);
  b2 := IsLetter('D2009', 2);
  ShowMessageFmt('%s,%s', [BoolToStr(b1,True),BoolToStr(b2,True)]);
  {True,False}
end;

{IsUpper: 是否是个大写字母}
procedure TForm1.Button2Click(Sender: TObject);
var
  b1,b2,b3: Boolean;
begin
  b1 := IsUpper('A'); {是}
  b2 := IsUpper('a'); {否}
  b3 := IsUpper('9'); {否}
  ShowMessageFmt('%s,%s,%s', [BoolToStr(b1,True),BoolToStr(b2,True),BoolToStr(b3,True)]);
  {True,False,False}

  b1 := IsUpper('Delphi', 1);
  b2 := IsUpper('Delphi', 2);
  ShowMessageFmt('%s,%s', [BoolToStr(b1,True),BoolToStr(b2,True)]);
  {True,False}
end;

{IsLower: 是否是个小写字母}
procedure TForm1.Button3Click(Sender: TObject);
var
  b1,b2,b3: Boolean;
begin
  b1 := IsLower('A'); {否}
  b2 := IsLower('a'); {是}
  b3 := IsLower('9'); {否}
  ShowMessageFmt('%s,%s,%s', [BoolToStr(b1,True),BoolToStr(b2,True),BoolToStr(b3,True)]);
  {False,True,False}

  b1 := IsLower('Delphi', 1);
  b2 := IsLower('Delphi', 2);
  ShowMessageFmt('%s,%s', [BoolToStr(b1,True),BoolToStr(b2,True)]);
  {False,True}
end;

{IsDigit: 是否是个十进制数字}
procedure TForm1.Button4Click(Sender: TObject);
var
  b1,b2,b3: Boolean;
begin
  b1 := IsDigit('A'); {否}
  b2 := IsDigit('½'); {否}
  b3 := IsDigit('9'); {是}
  ShowMessageFmt('%s,%s,%s', [BoolToStr(b1,True),BoolToStr(b2,True),BoolToStr(b3,True)]);
  {False,False,True}

  b1 := IsDigit('D2009', 1);
  b2 := IsDigit('D2009', 2);
  ShowMessageFmt('%s,%s', [BoolToStr(b1,True),BoolToStr(b2,True)]);
  {False,True}
end;

{IsNumber: 是否是个数字符号}
procedure TForm1.Button5Click(Sender: TObject);
var
  b1,b2,b3: Boolean;
begin
  b1 := IsNumber('A'); {是}
  b2 := IsNumber('½'); {是}
  b3 := IsNumber('9'); {否}
  ShowMessageFmt('%s,%s,%s', [BoolToStr(b1,True),BoolToStr(b2,True),BoolToStr(b3,True)]);
  {False,True,True}

  b1 := IsNumber('123¹²³¼½¾', 1);
  b2 := IsNumber('123¹²³¼½¾', 4); {这里的 9 个字符全都复合}
  ShowMessageFmt('%s,%s', [BoolToStr(b1,True),BoolToStr(b2,True)]);
  {True,True}
end;

end.