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Skriv ut en RTF-fil och definiera utskriftsområde Kategori: Skrivare
Inlagt: 2004-11-06
Läst: 1126
Inlagt av: Staffan Berg
Beskrivning
Lite avancerat exempel som demonstrerar hur du skriver ut innehållet i en RTF-fil. Du anger utskriftsutseende och utskriftsområde själv genom att ställa in marginler, sidstorlek, textområde m m. 
Kod
unit Unit1; 
 
interface 
 
uses 
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, 
 Dialogs, StdCtrls, RichEdit, RxRichEd, ExtCtrls, Printers; 
 
type 
 TPageOffset = record 
  mStart, 
  mEnd: Integer; 
  rendRect: TRect; 
 end; 
 TForm1 = class(TForm) 
  Panel1: TPanel; 
  Editor: TRxRichEdit; 
  PrintBtn: TButton; 
  PreviewBtn: TButton; 
  CloseBtn: TButton; 
  procedure PrintBtnClick(Sender: TObject); 
  procedure PreviewBtnClick(Sender: TObject); 
  procedure CloseBtnClick(Sender: TObject); 
  procedure FormShow(Sender: TObject); 
 private 
  { Private-Deklarationen } 
 public 
  { Public-Deklarationen } 
 end; 
 
var 
 Form1: TForm1; 
 
implementation 
 
uses Unit2; 
 
{$R *.dfm} 
 
procedure TForm1.PrintBtnClick(Sender: TObject); 
var  
 wPage, hPage, xPPI, yPPI, wTwips, hTwips: integer; 
 pageRect, rendRect: TRect; 
 po: TPageOffset; 
 fr: TFormatRange; 
 lastOffset, currPage, pageCount: integer; 
 xOffset, yOffset: integer; 
 FPageOffsets: array of TPageOffset; 
 TextLenEx: TGetTextLengthEx; 
 firstPage: boolean; 
begin 
 //First, get the size of a printed page in printer device units 
 wPage := GetDeviceCaps(Printer.Handle, PHYSICALWIDTH); 
 hPage := GetDeviceCaps(Printer.Handle, PHYSICALHEIGHT); 
 //Next, get the device units per inch for the printer 
 xPPI := GetDeviceCaps(Printer.Handle, LOGPIXELSX); 
 yPPI := GetDeviceCaps(Printer.Handle, LOGPIXELSY); 
 //Convert the page size from device units to twips 
 wTwips := MulDiv(wPage, 1440, xPPI); 
 hTwips := MulDiv(hPage, 1440, yPPI); 
 //Save the page size in twips 
 with pageRect do  
 begin 
  Left := 0; 
  Top := 0; 
  Right := wTwips; 
  Bottom := hTwips 
 end; 
 //Next, calculate the size of the rendering rectangle in twips 
 //Rememeber - two inch margins are hardcoded, so the below code 
 //reduces the width of the output by four inches 
 with rendRect do  
 begin 
  Left := 0; 
  Top := 0; 
  Right := pageRect.Right - (1440 * 4); 
  Bottom := pageRect.Bottom - (1440 * 4) 
 end; 
 //Define a single page and set starting offset to zero 
 po.mStart := 0; 
 //Define and initialize a TFormatRange structure. This structure is passed 
 //to the TRichEdit with a request to format as much text as will fit on a 
 //page starting with the chrg.cpMin offset and ending with the chrg.cpMax. 
 //Initially, we tell the RichEdit control to start at the beginning 
 //(cpMin = 0) and print as much as possible (cpMax = -1). We also tell it 
 //to render to the printer 
 with fr do  
 begin 
  hdc := Printer.Handle; 
  hdcTarget := Printer.Handle; 
  chrg.cpMin := po.mStart; 
  chrg.cpMax := -1; 
 end; 
 //In order to recognize when the last page is rendered, we need to know how 
 //much text is in the control. 
 if RichEditVersion >= 2 then  
 begin 
  with TextLenEx do  
  begin 
   flags := GTL_DEFAULT; 
   codepage := CP_ACP; 
  end; 
  lastOffset := SendMessage(Editor.Handle, EM_GETTEXTLENGTHEX, wParam(@TextLenEx), 0) 
 end 
 else  
  lastOffset := SendMessage(Editor.Handle, WM_GETTEXTLENGTH, 0, 0); 
 //As a precaution, clear the formatting buffer 
 SendMessage(Editor.Handle, EM_FORMATRANGE, 0, 0); 
 //Printers frequently cannot print at the absolute top-left position on the 
 //page. In other words, there is usually a minimum margin on each edge of the 
 //page. When rendering to the printer, RichEdit controls adjust the top-left 
 //corner of the rendering rectangle for the amount of the page that is 
 //unprintable. Since we are printing with two-inch margins, we are presumably 
 //already within the printable portion of the physical page. 
 SaveDC(fr.hdc); 
 SetMapMode(fr.hdc, MM_TEXT); 
 xOffset := GetDeviceCaps(Printer.Handle, PHYSICALOFFSETX); 
 yOffset := GetDeviceCaps(Printer.Handle, PHYSICALOFFSETY); 
 xOffset := xOffset + MulDiv(1440 + 1440, xPPI, 1440); 
 yOffset := yOffset + MulDiv(1440 + 1440, yPPI, 1440); 
 SetViewportOrgEx(fr.hdc, xOffset, yOffset, nil); 
 //Now we build a table of page entries, one entry for each page that would be 
 //printed. 
 while ((fr.chrg.cpMin <> -1) and (fr.chrg.cpMin < lastOffset)) do  
 begin 
  fr.rc := rendRect; 
  fr.rcPage := pageRect; 
  po.mStart := fr.chrg.cpMin; 
  fr.chrg.cpMin := SendMessage(Editor.Handle, EM_FORMATRANGE, 0, Longint(@fr)); 
  po.mEnd := fr.chrg.cpMin - 1; 
  po.rendRect := fr.rc; 
  if High(FPageOffsets) = -1 then SetLength(FPageOffsets, 1) 
  else  
   SetLength(FPageOffsets, Length(FPageOffsets) + 1); 
  FPageOffsets[High(FPageOffsets)] := po 
 end; 
 pageCount := Length(FPageOffsets); 
 ShowMessage(Format('Es wurde %d Seiten ermittelt', [pageCount])); 
 SendMessage(Editor.Handle, EM_FORMATRANGE, 0, 0); 
 RestoreDC(fr.hdc, - 1); 
 //Now, we are almost ready to actually print. 
 Printer.BeginDoc; 
 fr.hdc := Printer.Handle; 
 fr.hdcTarget := Printer.Handle; 
 SaveDC(fr.hdc); 
 SetViewportOrgEx(fr.hdc, xOffset, yOffset, nil); 
 //Ok, here we go to print 
 firstPage := True; 
 //At this point you can select from page and to page 
 currPage := 0; //Print from the first page 
 pageCount := 1; //Only One page for testing 
 while (currPage < pageCount) do  
 begin 
  if firstPage then firstPage := False 
  else  
   Printer.NewPage; 
  SetViewportOrgEx(fr.hdc, xOffset, yOffset, nil); 
  fr.rc := FPageOffsets[currPage].rendRect; 
  fr.rcPage := pageRect; 
  fr.chrg.cpMin := FPageOffsets[currPage].mStart; 
  fr.chrg.cpMax := FPageOffsets[currPage].mEnd; 
  fr.chrg.cpMin := SendMessage(Editor.Handle, EM_FORMATRANGE, 1, Longint(@fr)); 
  Inc(currPage); 
 end; 
 //At this point, we have finished rendering the contents of the RichEdit 
 //control. Now we restore the printer's HDC settings and tell Windows that 
 //we are through printing this document 
 RestoreDC(fr.hdc, - 1); 
 Printer.EndDoc; 
 //Finally, we clear the RichEdit control's formatting buffer and delete 
 //the saved page table information 
 fr.chrg.cpMin := SendMessage(Editor.Handle, EM_FORMATRANGE, 0, 0); 
 Finalize(FPageOffsets); 
 //That's it 
end; 
 
procedure TForm1.PreviewBtnClick(Sender: TObject); 
begin 
 PreviewForm.ShowModal 
end; 
 
procedure TForm1.CloseBtnClick(Sender: TObject); 
begin 
 Close 
end; 
 
procedure TForm1.FormShow(Sender: TObject); 
begin 
 Editor.Lines.LoadFromFile('Exceltabelle.rtf'); 
end; 
 
end. 

 
 
© Copyright 2005 - Staffan Berg
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