代码文件:
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} uses Character; {Character.ToUpper} procedure TForm1.Button1Click(Sender: TObject); var c: Char; str: string; begin c := ToUpper('a'); str := ToUpper('Delphi'); ShowMessageFmt('%s, %s', [c, str]); {A, DELPHI} end; {Character.ToLower} procedure TForm1.Button2Click(Sender: TObject); var c: Char; str: string; begin c := ToLower('A'); str := ToLower('Delphi'); ShowMessageFmt('%s, %s', [c, str]); {a, delphi} end; {相应的 API 函数: Windows.CharUpper、Windows.CharLower} procedure TForm1.Button3Click(Sender: TObject); var c1,c2: Char; begin c1 := Char(CharUpper(PChar('a'))); c2 := Char(CharLower(PChar('B'))); ShowMessageFmt('%s, %s', [c1, c2]); {A, b} end; {以前 SysUtils 下有: UpperCase、LowerCase} procedure TForm1.Button4Click(Sender: TObject); var s1,s2: string; begin s1 := UpperCase('Delphi'); s2 := LowerCase('Delphi'); ShowMessageFmt('%s, %s', [s1, s2]); {DELPHI, delphi} end; end.窗体文件:
object Form1: TForm1 Left = 0 Top = 0 Caption = 'Form1' ClientHeight = 141 ClientWidth = 251 Color = clBtnFace Font.Charset = DEFAULT_CHARSET Font.Color = clWindowText Font.Height = -11 Font.Name = 'Tahoma' Font.Style = [] OldCreateOrder = False PixelsPerInch = 96 TextHeight = 13 object Button1: TButton Left = 88 Top = 8 Width = 75 Height = 25 Caption = 'Button1' TabOrder = 0 OnClick = Button1Click end object Button2: TButton Left = 88 Top = 39 Width = 75 Height = 25 Caption = 'Button2' TabOrder = 1 OnClick = Button2Click end object Button3: TButton Left = 88 Top = 70 Width = 75 Height = 25 Caption = 'Button3' TabOrder = 2 OnClick = Button3Click end object Button4: TButton Left = 88 Top = 101 Width = 75 Height = 25 Caption = 'Button4' TabOrder = 3 OnClick = Button4Click end end