Delphi tilida
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• EndDoc usuli bilan grafik ma’lumot printerga yuboriladi. Print Demo P rinl ln lo ri m ndr = => P fin lc r p rin ts lc x t in lc x t m o d c I-] P rin t lo rm Dastur matni: Unit Pri_form; interface uses 148
TForml = class(TForm) Buttonl: TButton; Labell: TLabel; Label2: TLabel; Bevell: TBevel; Button2: TButton; Bevel2: TBevel; Button3: TButton; Label3: TLabel; Panell: TPanel; Imaoel: Tlmage; procedure ButtonlClick(Sender: TObject); procedure Button2Click(Sender: TObject); procedure Button3Click(Sender: TObject); private { Private declarations } public { Public declarations } end; Forml: TForml; implementation {$R *.DFM} To_Prn : TextFile; Begin Buttonl.Enabled:=False; AssignPrn(To_Prn); Rewrite(To_Pm); Writeln(To_Prn, Label2.Caption); Procedure TForml.Button2Click(Sender: TObject); Begin 149 Button2.Enabled:=False; Forml.Print; end; BeginDoc; Canvas.Draw(0,0,Image 1. Picture. Bitmap); NewPage; Canvas.StretchDraw(Rect(0, 0,300, 300), Image1.Picture.Bitmap); EndDoc; S a v o 11 a r 150
YI.DELPHI TILINING IMKONIYATLARI 6.1.Yozuvlarni faylga yozish va fayldan o‘qish Yozuvlami faylda saqlash mumkin. Dastuming o‘zgaruvchi yozuv qiymatini faylda saqlash uchun yozuv turidagi faylni e’lon qilish kerak. Misol uchun: Type TRerson = record f riame: string [20] ; l name: string[20]; address: string[50]; end; var f: file of TPerson; Instmksiya komponentalari TPerson turidagi yozuvlar bolgan faylni e’lon qiladi. Yozuvlar fayli bilan ishlash oddiy fayllar bilan ishlashdan farq qilmaydi. Yozuvlarni faylgayozish u s s x m s a m w m Sfalwnw | MMMKlll 3
I-----------3 MMltJ IC K*n»ii»h Killmnli ~oj*j Foydalanuvchi tomo- nidan kiritiluvchi muso- baqa natijalarini faylga yozuvchi dastumi ko‘rib chiqamiz. M a’lumotlar dialog oynasiga kiritilib, komponentalari TMedal turidagi yozuvlar bolgan faylda saqlanadi. Sportsmen familiyasini kiritish uchun Edit kom- ponentasi ishlatiladi. Sport turi va mamlakat nomini kiritish uchun ComboBox komponentasi ishlatiladi. Ro‘yxatnihosil qilish uchun Object Inspector oynasida Items xossasini tanlab, uch nuqtali tugmasini bosib, ro‘yxat muharririni aktiv- lashtirish lozim. 151 String list EJitor 5 t o n zbekis:on PciS-Siyy 'fan^iys LJ £odeEd)« C * Y ti Dastur matni: Unit Unitl; interface uses Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, Grids, ExtCtrls; Type TForml = class(TForm) Editl: TEdit; Label2: TLabel; Label3: TLabel; Label4: TLabel; Label5: TLabel; Buttonl: TButton; ComboBoxl: TComboBox; ComboBox2: TComboBox; RadioGroupl: TRadioGroup; procedure FormActivate(Sender: TObject); procedure FormClose(Sender: TObject; var Action: TCloseAction); procedure ButtonlClick(Sender: TObject); private 152 { Private declarations } public { Public declarations } end; TKind = (GOLD, SILYER, BRONZE); TMedal=record country: string[20]; sport: string[20]; person: string[40]; kind: TKind; end; Var Forml: TForml; f: file of TMedal; implementation {$R *.DFM} procedure TForml.FormActivate(Sender: TObject); var resp : word; begin AssignFile(f,' a:\medals.db'); {$1-} Reset (f); Seek(f, FileSize(f)); {$1+} if IOResult = 0 then buttonl.enabled:=TRUE; else begin resp:=MessageDlg(' 153
begin with medal do begin country := ComboBoxl.Text; sport := ComboBox2.Text; person := Editl.Text; case RadioGroupl.ItemIndex of 0: kind := GOLD; 1: kind := SILVER; 2: kind := BRONZE; end; end; write(f,medal); end; procedure TForml.FormClose(Sender: TObject; var Action: TCloseAction); begin CloseFile(f); end. Bu dasturda TForml.FormActivate protsedurasi faylni ochadi. Fayl matnli bolmagani uchun Rewrite protsedurasi bilan ochilib Seek protsedurasi ko‘rsatgichni fayl oxiriga o‘rnatadi. TForml.ButtonlClickprotsedurasi faylgayozuv qo‘shishni amalga oshiradi. TFormLFormClose protsedurasi faylni berkitadi. Ko‘rilgan dasturda ro‘yxat loyihalashtirish jarayonida o‘rnatiladi. Dastur bajarilishjarayonida ro‘yxatni o‘rnatish uchun items xossasiga Add usulini qollash kerak. Masalan: Forml.ComboBoxl.Item.Add(' Rossiya'); FormLComboBoxl .Item.Add(' Avstriya'); Forml.ComboBoxl.Item.Add(' Germaniya'); Forml.ComboBoxl.Item.Add(' Fransiya'); Fayldan yozuvni o‘qish Quyidagi dasturda fayl ochilib, hamma mamlakatlar yoki tanlangan mamlakat sportchilari tomonidan yutib olingan medallar ro‘yxatini ekranga chiqaradi. 154 Quyidagi jadvalda forma komponentalari xossalari berilgan: Xossa Qiymat RadioButtonl.Checked Labell.Enabled ComboBoxLEnabled Memo1.Readonly Memo1.ScrollBars True False False True Vertical Mamlakat nomini tanlash uchun ComboBoxl komponentasidan foydalanilgan. Ro‘yxat loyihalashtirish jarayonida kiritilishi lozim. Dastur matni: Unit Unitl; interface -^5 - |Q| xl C H iin n ih iii C Tb-nilisll M.iim1>ih.]l Procedure ButtonlClick(Sender: TObject); procedure RadioButton2Click(Sender: TObject); procedure RadioButtonlClick(Sender: TObject); private { Private declarations } public { Public declarations } end; Var Forml: TForml; implementation {$R *.DFM} procedure TForml.ButtonlClick(Sender: TObject) ; Type / / tip medali TKind = (GOLD,SILVER,BRONZE); / / zapis fayla TMedal = record country:string[20]; sport:string[20]; person:string[40]; kind:TKind; end; Var f: file of TMedal; rec: TMedal; n: Integer; st: string[80]; Begin AssionFile(f, ’a:\medals.db’); {$!-} 156 Memol.Clear; / / OMHCTHTb cnncoK nojia Memo while not EOF(f) do begin read(f, rec); / / npoMHTaTb 3anncb if RadioButtonl.Checked or (rec.country = ComboBoxl.Text) then begin n := n + 1; st := rec.person+ ', ' + rec.sport; if RadioButtonl.Checked then st := st + ', '+ rec.country; case rec.kind of OOLD: st := st+ ', oltin'; SILVER:st := st+ ', kumush'; BRONZE:st := st+ ', bronza'; end; Memol.Lines.Add(st); end; end; CloseFile(f); if n = 0 then ShowMessage('Kerakli maiumot yo‘q.'); end; Procedure TForml.RadioButton2Click(Sender: TObject); Begin Labell.Enabled := True; ComboBoxl.Enabled := True; ComboBoxl.SetFocus; end; Procedure TForml.RadioButtonlClick(Sender: TObject); Begin Labell.Enabled := False; ComboBoxl.Enabled := False; end; end. 157
TForml.ButtonlClick protsedurasi faylni ochib yozuvlami ketma- ket o‘qiydi. Yozuv Memol maydoniga, mamlakat nomi country maydoni qiymatibilan mos kelsa yoki RadioButtonl tanlangan bolsa qo‘shiladi. 6.2. Dinamik tuzilmalar Ko‘rsatkich deb qiymati boshqa o‘zgaruvchi yoki ma’lumotlar tuzilmasi adresiga teng bolgan o‘zgaruvchiga aytiladi. Ko‘rsatkichlar quyidagicha ta’riflanadi: Nom: ATur; Masalan: pl: AInteger; r2: Areal; Agar ko‘rsatkich hech narsaga tengligi ko‘rsatilmasa uning qiymati NIL ga teng deyiladi. Ko‘rsatkichga biror o‘zgaruvchi adresi qiymat sifatida berilsa @ adres olish operatoridan foydalaniladi. Masalan: r := @n; Ko‘rsatkichga boshqa ko‘rsatkich qiymatini berish mumkin, agar ular bir turli bo‘lsa. Masalan: p2 := pl; Agar ko‘rsatkich i o‘zgaruvchiga ko‘rsatayotgan bo‘lsa. rA: = 5; instruksiya bajarilgandan so‘ng i qiymati 5 ga teng boladi. |