delphi - 使用delphi打印文本文件所需的帮助

Question

我试图用Delphi 2010打印文本文件。我找到了一些代码，但是当我运行时，它要求保存一个xps文件，它不显示打印对话框。该代码位于http://www.delphipages.com/forum/showthread.php?t=72986

procedure TForm1.print_btnClick(Sender: TObject);
var
  filename: string;
begin
  filename := 'printfile.txt';
  ShellExecute(handle, 'print', pchar(Filename), nil, nil, SW_NORMAL);
end;

另一个位于http://www.delphibasics.co.uk/Article.asp?Name=Printing

这一次又一次循环“确定”对话框，它无法打印任何内容。

问候

Answer 1

选项1

您可以编写自己的打印代码。一个简单的例子（uses Printers）：

procedure PrintTextFile(const FileName: string; const Numbering: boolean = true);
const
  FONT_NAME = 'Times New Roman';
  FONT_SIZE = 10;
var
  MARGIN: integer;
  sl: TStringList;
  i, h: Integer;
  r, rFooter: TRect;
  s: string;
  DocEnd: integer;
begin
  with TPrintDialog.Create(nil) do
    try
      if not Execute then
        Exit;
    finally
      Free;
    end;
  sl := TStringList.Create;
  try
    sl.LoadFromFile(FileName);
    Printer.BeginDoc;
    Printer.Title := FileName; // or application name or sth else
    Printer.Canvas.Font.Name := FONT_NAME;
    Printer.Canvas.Font.Size := FONT_SIZE;
    MARGIN := 5*Printer.Canvas.TextWidth('M');
    DocEnd := Printer.PageHeight - MARGIN;
    if Numbering then
    begin
      dec(DocEnd, 2*Printer.Canvas.TextHeight('8'));
      rFooter := Rect(0, DocEnd, Printer.PageWidth, Printer.PageHeight - MARGIN);
      DrawText(Printer.Canvas.Handle,
        PChar(IntToStr(Printer.PageNumber)),
        length(IntToStr(Printer.PageNumber)),
        rFooter,
        DT_SINGLELINE or DT_CENTER or DT_BOTTOM);
    end;
    r.Left := MARGIN;
    r.Top := MARGIN;
    for i := 0 to sl.Count - 1 do
    begin
      r.Right := Printer.PageWidth - MARGIN;
      r.Bottom := DocEnd;
      s := sl.Strings[i];
      if s = '' then s := ' ';
      h := DrawText(Printer.Canvas.Handle, // Height of paragraph on paper
        PChar(s),
        length(s),
        r,
        DT_LEFT or DT_TOP or DT_WORDBREAK or DT_CALCRECT);
      if r.Top + h >= DocEnd then
      begin
        Printer.NewPage;
        if Numbering then
          DrawText(Printer.Canvas.Handle,
            PChar(IntToStr(Printer.PageNumber)),
            length(IntToStr(Printer.PageNumber)),
            rFooter,
            DT_SINGLELINE or DT_CENTER or DT_BOTTOM);
        r.Top := MARGIN;
        r.Bottom := DocEnd;
      end;
      if h > Printer.PageHeight - 2*MARGIN then
        raise Exception.Create('Line too long to fit on single page.');
      DrawText(Printer.Canvas.Handle,
        PChar(s),
        length(s),
        r,
        DT_LEFT or DT_TOP or DT_WORDBREAK);
      inc(r.Top, h);
    end;
    Printer.EndDoc;
  finally
    sl.Free;
  end;
end;

警告：如果文本文件中的任何一行太宽以致于不能放在一张纸上（包装后），上述代码将不起作用。我太累了，无法立即解决该问题。

选项2

一个讨厌的技巧是使用不可见的TRichEdit进行打印。

procedure PrintTextFile(AOwner: TWinControl; const FileName: string);
begin
  with TRichEdit.Create(nil) do
    try
      Visible := false;
      Parent := AOwner;
      Lines.LoadFromFile(FileName);
      with TPrintDialog.Create(nil) do
        try
          if Execute then
            Print(FileName);
        finally
          Free;
        end;
    finally
      Free;
    end;
end;

我建议不要这样做，因为它太讨厌了。