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.
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