Delphi典型例子.doc

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1、习题1procedure TForm1.Button1Click(Sender: TObject);begin if (edtName.Text=admin)and(edtPass.Text=123456) then begin showmessage(豋录成功。); end else showmessage(姓名戓密码错。);end;习题2var Form1: TForm1;implementation$R *.dfm const iname=user; ipassword=00000;procedure TForm1.Button1Click(Sender: TObject);begin

2、if ( edit1.text=iname)and(edit2.text=ipassword) then ShowMessage( 欢迎使用学生管理系统)else MessageDlg( 用户名或密码不正确,请重新输入!,mtError,mbOk,0);end;习题3var r,c,s:real;const pi=3.14159; / 常量的定义beginr:=strtofloat(edit1.Text);c:=2*pi*r;s:=pi*sqr(r);label2.Caption:=该圆的周长为：+floattostr(c)+ +chr(13)+面积为:+floattostr(s);end;p

3、rocedure TForm1.Button2Click(Sender: TObject);beginclose;end;习题4if 2 1 then begin a:=A;end else c:=Cend;求分段函数的值：procedure TForm1.Button1Click(Sender: TObject);varx,y:real;begin x:=strtofloat(edit1.text); y:=x2+x*x-x+2; edit2.Text:=floattostr(y);end;procedure TForm1.Button2Click(Sender: TObject);begi

4、nclose;end;(*清除按钮的OnClick事件处理代码*)procedure TForm1.Button2Click(Sender: TObject);begin Edit1.Text:=; Edit2.Text:=; Edit3.Text:=; Edit4.Text:=;end;习题4procedure TForm1.Button3Click(Sender: TObject);beginClose;begin if Label1.Visible then begin Label1.Visible:=False; /如果是显示的，则隐藏 Button1.Caption:=显示; end

5、 else begin Label1.Visible:=True; /如果是隐藏的，则显示 Button1.Caption:=隐藏; end;end;习题5procedure TForm1.Button1Click(Sender: TObject);var year:Integer; flag:Boolean;begin year:=StrtoInt(Edit1.text); /将字符串转变为整型 if year mod 4 = 0 then begin if year mod 100 =0 then begin if year mod 400=0 then flag:=true else f

6、lag:=false; end else flag:=true; end else flag:=false; if flag then Label2.Caption:=Edit1.text+年是闰年。 else Label2.Caption:=Edit1.text+年不是闰年。;end;习题6procedure TForm1.Button1Click(Sender: TObject);var n,i,p:integer;begin n:=strtoint(Edit1.Text); i:=1; p:=1; if n0 then begin while iRadioGroup1.ItemIndex

7、1 then Edit1.Text:=只能选+IntTostr(RadioGroup1.ItemIndex+1)+个城市;end;procedure TForm1.Button2Click(Sender: TObject);beginclose;end;end习题9unit Unit4_3;interfaceuses Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, CheckLst, ComCtrls;type TForm1 = class(TForm) Label1: T

8、Label; ListBox1: TListBox; Label2: TLabel; CheckListBox1: TCheckListBox; Label3: TLabel; ComboBox1: TComboBox; RichEdit1: TRichEdit; Label4: TLabel; Button1: TButton; Button2: TButton; Button3: TButton; procedure Button1Click(Sender: TObject); procedure Button3Click(Sender: TObject); procedure Butto

9、n2Click(Sender: TObject); private Private declarations public Public declarations end;var Form1: TForm1;implementation$R *.DFMprocedure TForm1.Button1Click(Sender: TObject);var Item:integer;begin RichEdit1.Lines0:=我最喜欢的PC机品牌有:; RichEdit1.Lines1:=; /PC机品牌 for Item:=0 to ListBox1.Items.Count-1 do if L

10、istBox1.SelectedItem then RichEdit1.Lines1:=RichEdit1.Lines1+ListBox1.Items.StringsItem+ ; RichEdit1.Lines3:=我最喜欢的手机品牌有:; RichEdit1.Lines4:=; /手机品牌 for Item:=0 to CheckListBox1.Items.Count-1 do if CheckListBox1.CheckedItem then RichEdit1.Lines4:=RichEdit1.Lines4+CheckListBox1.Items.StringsItem+ ; Ri

11、chEdit1.Lines6:=我最近想买+ComboBox1.Text;end;procedure TForm1.Button2Click(Sender: TObject);var Item:integer;begin for Item:=0 to ListBox1.Items.Count-1 do ListBox1.SelectedItem:=false; for Item:=0 to CheckListBox1.Items.Count-1 do CheckListBox1.CheckedItem:=false; for Item:=0 to RichEdit1.Lines.Count-1 do RichEdit1.LinesItem:=;end;procedure TForm1.Button3Click(Sender: TObject);begin Close;end;是WIN7吗，权限问题。1. 程序右键，以管理权限运行。2. 将Delphi7目录只读取消。WIN7以上的操作系统正常运行程序不是以管理员方式运行的。