prints.pas

一个信息查询系统,主要功能文件上传下载,信息浏览,打印等

unit prints;
interface
uses
 Windows, SysUtils, Classes, Graphics, Forms, Controls, StdCtrls, 
  Buttons, ExtCtrls, ExtDlgs, Dialogs,printers,jpeg;
 type
  tprintthread=class(tthread)
  private

  i:integer;
  protected
  procedure execute;override;  
  public
  constructor create();


  end;
implementation
 uses pic;
 constructor tprintthread.create();
 begin 
 inherited create(false);

 end;
 procedure tprintthread.execute;
 var
    prnrect,imagrect:trect;
    centerx,centery,x1,y1,x2,y2:integer;
     pheight,pwidth:integer;
    destrect,sourect:trect; bt,bt1:Tbitmap;
 begin

         pheight:=printer.pageheight;
         pwidth:=printer.pagewidth;
         destrect.Top:=0;
         destrect.Left:=0;
      if pheight>round((OKBottomDlg5.image1.Picture.Height*pwidth)/OKBottomDlg5.image1.Picture.Width) then
          begin
         DestRect.Right:=pwidth;
         DestRect.Bottom:=round((OKBottomDlg5.image1.Picture.Height*pwidth)/OKBottomDlg5.image1.Picture.Width);
         end
         else
          begin
         DestRect.Right:=round((OKBottomDlg5.image1.Picture.Width*pheight)/OKBottomDlg5.image1.Picture.Height) ;
         destrect.Bottom:=pheight;
          end;
    bt:=Tbitmap.Create();
    bt1:=Tbitmap.Create();
    bt.Canvas.Lock;
    bt1.Canvas.Lock;
    try
        bt.PixelFormat:=pf24bit;
        bt.Width:=OKBottomDlg5.image1.Picture.Width;
        bt.Height:=OKBottomDlg5.image1.Picture.Height;
        bt.Assign(OKBottomDlg5.image1.Picture.Graphic);
        bt1.PixelFormat:=pf24bit;
        bt1.Width:=DestRect.Right;
        bt1.Height:=destrect.Bottom;
        bt1.Canvas.StretchDraw(destrect,bt);
    finally
    bt.Canvas.Unlock;
    bt.Free;
    end;
    try  
     with bt1 do
      begin
     try
         printer.begindoc;
         centerx:=pwidth div 2;
         centery:=pheight div 2;
         x1:=centerx-(DestRect.Right div 2);
         y1:=centery-(destrect.Bottom div 2);
         x2:=centerx+(DestRect.Right div 2);
         y2:=centery+(destrect.Bottom  div 2);
         prnrect:=rect(x1,y1,x2,y2);
         imagrect:=rect(0,0,bt1.Width,bt1.Height);
         printer.Canvas.CopyRect(prnrect,bt1.Canvas,imagrect);
         printer.EndDoc;
         except
          application.MessageBox('打印终止','提示',mb_ok);
         end;
         end;
         finally
         bt1.Canvas.Unlock;
         bt1.Free;
        end;

 end;
end.