Delphi pdf generate - 分页

Question

什么库（Debenu，Gnostic，其他？）允许我从数据库nad读取文本然后将其插入pdf文件，但是有分页？例如，我在数据库中有1000行，但是一个A4页面仅适用于250行，所以我需要4页，而不是一个小字体...

在将文本发送到pdf之前是否可以测量文本的高度？

Answer 1

如果您使用的是Gnostice eDocEngine，则可以使用PDF引擎的AutoPaginate属性自动创建额外的页面。您使用常规Delphi类从数据库中读取记录，然后开始写入PDFEngine中的页面，当您开始耗尽页面空间时，PDFEngine将自动生成新页面并适应您的文本输出。您可以选择任何页面大小。

此示例直接来自帮助文件。

{
  This example illustrates autopagination and the use of
  built-in and custom placeholders.

  Drag a button component and a PDF engine component
  on a form. Double-click the button and use the
  following code for the click-event procedure.
}

procedure TForm3.Button1Click(Sender: TObject);
var
 i: Integer;
begin

  with gtPDFEngine1 do begin
    FileName := 'autopagination_placeholders_demo.pdf';
    Font.Size := 16;
    Font.Name := 'Times New Roman';
    TextFormatting.LineSpacing := 2;

    // Enable autopagination
    AutoPaginate := true;

    // Ensure all text placeholders are replaced at run-time
    Preferences.CalculateVariables := true;

    // Render pages after processing all instructions
    Preferences.ProcessAfterEachPage  // Required for generating values
         := false;                    // for built-in placeholders

    // Specify event handler for placeholder substitution events
    OnCalcVariables := gtPDFEngine1CalcVariablesEventHandler;

    BeginDoc;
    for i := 1 to 50 do begin
      // Render paragraph containing built-in and custom placeholders
      BeginPara;
      Textout('Hello, world! - on page #' +
              CphPageNo + ' of ' + CphTotalPages +
              ' - Random #<%my_random_number_placeholder%>');
      EndPara;
    end;
    EndDoc;
  end;
  Close;

end;

// Event handler that gets called whenever a placeholder is substituted.
procedure TForm3.gtPDFEngine1CalcVariablesEventHandler(
                      Sender: TgtCustomDocumentEngine;
                      Variable: String;
                      var Value: String);
begin
  // Provide a value for the custom placeholder
  if Variable = 'my_random_number_placeholder' then begin
    Value := FloatToStr(Random);
  end;
end;