面向 Delphi 的完整 PDF 生命周期，无需部署任何 DLL

var
  oPDF: TsgcPDFDocument;
  oPage: TsgcPDFPage;
begin
  oPDF := TsgcPDFDocument.Create;
  try
    oPDF.Info.Title := 'Hello sgcPDF';
    // A4 竖向：595 x 842 点
    oPage := oPDF.AddPage(595, 842);
    oPage.DrawTextColor('Hello sgcPDF', 50, 780, sfHelveticaBold, 24, 0, 0.2, 0.6);
    oPage.DrawLine(50, 770, 545, 770, 1.5);
    oPage.DrawText('A PDF written in pure Pascal.', 50, 740, sfHelvetica, 12);
    // 用户密码用于打开文件，所有者密码授予完全权限
    oPDF.SetEncryption(emAES_256, 'user123', 'owner456');
    oPDF.SaveToFile('hello.pdf');
  finally
    oPDF.Free;
  end;
end;

var
  oSigner: TsgcPDFSignatureHandler;
begin
  oSigner := TsgcPDFSignatureHandler.Create;
  try
    oSigner.LoadCertificateFromPFX('signer.pfx', 'test123');
    oSigner.Reason := 'Document approval';
    oSigner.Location := 'Barcelona';
    oSigner.HashAlgorithm := shaSHA256;
    // 第 1 页上的可见签名字段：左、下、右、上
    oSigner.SetField('Signature1', 0, 50, 50, 250, 100);
    oSigner.SignDocument('contract.pdf', 'contract-signed.pdf');
  finally
    oSigner.Free;
  end;
end;

var
  oPDF: TsgcPDFDocument;
  oRenderer: TsgcPDFRendererRaster;
  oPage: TsgcPDFPage;
begin
  oPDF := TsgcPDFDocument.Create;
  try
    oPDF.LoadFromFile('report.pdf');
    oPage := oPDF.Pages[0];
    // 纯 Pascal 光栅化器：不依赖 GDI，可在 Windows 和 Linux 服务器上运行
    oRenderer := TsgcPDFRendererRaster.Create;
    try
      oRenderer.RenderPageToPNG(oPDF.Parser, oPage.PageDict,
        Round(oPage.Width * 150 / 72), Round(oPage.Height * 150 / 72),
        'page1.png');
    finally
      oRenderer.Free;
    end;
  finally
    oPDF.Free;
  end;
end;