unit1.pas

Delphi实效编程百例的随书源代码 这是其中的操作系统部分

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ExtCtrls, StdCtrls,printers;

type
  TForm1 = class(TForm)
    Memo1: TMemo;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Image1: TImage;
    PrintDialog1: TPrintDialog;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var 
lines:integer; 
prntext:system.text; 
//将PRNTEXT声明为一个在SYSTEM程序单元当中定义的文本文件 
begin
if printdialog1.execute then
assignprn(prntext); //将PRNTEST分配给打印机
rewrite(prntext); //调用REWRITE函数,为输出打开已分配的文件 
printer.canvas.font:=memo1.font; 
//把当前MEMO1的字体指定给打印对象的CANVAS的字体属性 
for lines:=0 to memo1.lines.count-1 do 
writeln(prntext,memo1.lines[lines]); 
//把MEMO的内容写到打印机对象 
system.close(prntext); //关闭打印文件 
end; 

procedure TForm1.FormCreate(Sender: TObject); 
begin
memo1.lines.loadfromfile('d:\private\1.txt'); 
//在FORM建立时读入d:\private\1.TXT文件 
end;




procedure TForm1.Button2Click(Sender: TObject);
begin
if printdialog1.execute then 
begin 
printer.begindoc; 
printer.canvas.draw(0,0,image1.picture.graphic); 
printer.enddoc; 
end;
end;

procedure TForm1.Button3Click(Sender: TObject);
VAR 
strect:Trect; //定义打印输出矩形框的大小 
temhi,temwd:integer; 
begin 
if printdialog1.execute then 
begin 
temhi:=image1.picture.height; 
temwd:=image1.picture.width; 
while (temhi<printer.pageheight div 2)and //将图形放大到打印页面的1/2
(temwd<printer.pagewidth div 2) do
begin 
temhi:=temhi+temhi; 
temwd:=temwd+temwd; 
end; 
with strect do //定义图形在页面上的中心位置输出 
begin 
left:=(printer.pagewidth -temwd) div 2; 
top:=(printer.pageheight-temhi) div 2; 
right:=left+temwd; 
bottom:=top+temhi; 
end; 
with Printer do 
begin 
begindoc; //将放大的图形向打印机输出 
canvas.stretchdraw(strect,image1.picture.graphic);
enddoc; 
end; 
end; 
end; 


end.