Advanced Features

Sending Pdf to Browser for Download

Sometimes when you are developing an ASP.NET application, you need to send PDF file(s) to web browser(s) for download without saving them physically. In order to achieve that you can save PDF document into MemoryStream object after generating it and pass bytes from that MemoryStream to Response object. Doing this will make the browser to download the generated PDF document.

Following code snippet demonstrate the above functionality:

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.Pdf-for-.NET
Aspose.Pdf.Document doc = new Aspose.Pdf.Document();
doc.Pages.Add().Paragraphs.Add(new Aspose.Pdf.Text.TextFragment("Hello World"));
MemoryStream ms = new MemoryStream();
doc.Save(ms);
Response.Clear();
Response.ClearHeaders();
Response.ClearContent();
Response.Charset = "UTF-8";
Response.AddHeader("content-length", ms.Length.ToString());
Response.AddHeader("content-disposition", String.Format("attachment;filename=TestDocument.pdf", "FileName"));
Response.ContentType = "application/pdf"; Response.BinaryWrite(ms.ToArray());
Response.Flush();
Response.End();

Extracting embedded files from a PDF file

Aspose.PDF stands out when it comes to advanced features for working with PDF format files. It extracts embedded files way better than other tools offering this feature.

With Aspose.PDF for .NET, you can efficiently extract any embedded file which may be an embedded font, an image, a video or an audio. Following goal-specific approach demonstrates how quickly and efficiently the embedded files can be extracted. Aspose.PDF facilitates you to extract all the font files whether it is a true type (TTF) or an open type font (OTF). Likewise, using this feature, image of any format JPG, PNG, SVG etc can be extracted in its ‘as is’ condition.

Following code snippet extracts all the embedded files from a PDF file:

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_DocumentConversion();            
// Load source PDF file
Document doc = new Document(dataDir + "input.pdf");
// Save output in XML format
doc.Save(dataDir + "PDFToXML_out.xml", SaveFormat.MobiXml);

Use of Latex Script to Add Mathematical Expressions

With Aspose.PDF, you can add mathematical expressions/formulas inside PDF document using latex script. Following examples show how this feature can be used in two different ways, in order to add a mathematical formula inside a table cell:

Without preamble and document environment

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_Text();
// Create a new Document Object
Document doc = new Document();
// Add Page in Pages Collection
Page page = doc.Pages.Add();
// Create a Table
Table table = new Table();
// Add a row into Table
Row row = table.Rows.Add();
// Add Cell with Latex Script to add methematical expressions/formulae
string latexText1 = "$123456789+\\sqrt{1}+\\int_a^b f(x)dx$";
Cell cell = row.Cells.Add();
cell.Margin = new MarginInfo { Left = 20, Right = 20, Top = 20, Bottom = 20 };
// Second LatexFragment constructor bool parameter provides LaTeX paragraph indents elimination.
LatexFragment ltext1 = new LatexFragment(latexText1, true);
cell.Paragraphs.Add(ltext1);
// Add table inside page
page.Paragraphs.Add(table);
// Save the document
doc.Save(dataDir + "LatextScriptInPdf_out.pdf");

With preamble and document environment

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_Text();
// Create a new Document Object
Document doc = new Document();
// Add Page in Pages Collection
Page page = doc.Pages.Add();
// Create a Table
Table table = new Table();
// Add a row into Table
Row row = table.Rows.Add();
// Add Cell with Latex Script to add methematical expressions/formulae
string latexText2 = @"\documentclass{article}
                    \begin{document}
                    Latex and the document class will normally take care of page layout issues for you. For submission to an academic publication, this entire topic will be out
                    \end{document}";
Cell cell = row.Cells.Add();
cell.Margin = new MarginInfo { Left = 20, Right = 20, Top = 20, Bottom = 20 };
HtmlFragment text2 = new HtmlFragment(latexText2);
cell.Paragraphs.Add(text2);
// Add table inside page
page.Paragraphs.Add(table);
// Save the document
doc.Save(dataDir + "LatextScriptInPdf2_out.pdf");

Support for Latex Tags

The align environment is defined in amsmath package, and proof environment is defined in amsthm package. Thus, you have to specify these packages using \usepackage command in the document preamble. And this means that you have to enclose the LaTeX text into document environment either as shown in the following code sample.

// For complete examples and data files, please go to https://github.com/aspose-pdf/Aspose.PDF-for-.NET
var dataDir = RunExamples.GetDataDir_AsposePdf_Text();
var s = @"
\usepackage{amsmath,amsthm}
\begin{document}
\begin{proof} The proof is a follows: 
\begin{align}
(x+y)^3&=(x+y)(x+y)^2
(x+y)(x^2+2xy+y^2)\\
&=x^3+3x^2y+3xy^3+x^3.\qedhere
\end{align}
\end{proof}
\end{document}";

var doc = new Document();
var page = doc.Pages.Add();

var latex = new LatexFragment(s);

page.Paragraphs.Add(latex);
doc.Save(dataDir + "Script_out.pdf");