高级功能

将 PDF 发送到浏览器以供下载

有时，当您开发 ASP.NET 应用程序时，您需要将 PDF 文件发送到网页浏览器以供下载，而无需将其物理保存。为了实现这一点，您可以在生成 PDF 文档后将其保存到 MemoryStream 对象中，并将该 MemoryStream 的字节传递给 Response 对象。这样做将使浏览器下载生成的 PDF 文档。

以下代码片段演示了上述功能：

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private void Page_Load(object sender, EventArgs e)
{
    // Clear the response before writing to it
    Response.Clear();
    // Set content type for PDF
    Response.ContentType = "application/pdf";
    // Set the response header for file download
    Response.AddHeader("content-disposition", "attachment; filename=TestDocument.pdf");

    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add Page in Pages Collection
        var page = document.Pages.Add();
        var textFragment = new Aspose.Pdf.Text.TextFragment("Hello World");
        page.Paragraphs.Add(textFragment);
        
        // Save PDF document to a MemoryStream
        using (var ms = new MemoryStream())
        {
            document.Save(ms);
             // Reset the stream position to the beginning
            ms.Position = 0;

            // Write the MemoryStream to the response
            ms.CopyTo(Response.OutputStream);
            Response.AddHeader("content-length", ms.Length.ToString());
            Response.Flush();
            // Suppress the remaining content
            Response.SuppressContent = true; 
        }
    }
    // End the response to prevent further processing
    Response.End(); 
}

使用 LaTeX 脚本添加数学表达式

使用 Aspose.PDF，您可以使用 LaTeX 脚本在 PDF 文档中添加数学表达式/公式。以下示例展示了如何以两种不同的方式使用此功能，以便在表格单元格中添加数学公式：

无前言和文档环境

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

有前言和文档环境

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void LatexWithPreambleAndDocEnvironment()
{
    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Text();
    // Open PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add page
        var page = doc.Pages.Add();
        // Create a Table
        var table = new Aspose.Pdf.Table();
        // Add a row into Table
        var row = table.Rows.Add();
       // Add Cell with Latex Script to add methematical expressions/formulae
        var 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}";
        var cell = row.Cells.Add();
        cell.Margin = new Aspose.Pdf.MarginInfo { Left = 20, Right = 20, Top = 20, Bottom = 20 };
        var text2 = new Aspose.Pdf.HtmlFragment(latexText2);
        cell.Paragraphs.Add(text2);
        // Add table inside page
        page.Paragraphs.Add(table);
        // Save PDF document
        document.Save(dataDir + "LatextScriptInPdf2_out.pdf");
    }
}

对 LaTeX 标签的支持

对齐环境在 amsmath 包中定义，证明环境在 amsthm 包中定义。因此，您必须在文档前言中使用 \usepackage 命令指定这些包。这意味着您必须将 LaTeX 文本封装在文档环境中，如以下代码示例所示。

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void LatexTagsSupport()
{
    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}";

    // The path to the documents directory
    var dataDir = RunExamples.GetDataDir_AsposePdf_Text();
    
    // Create PDF document
    using (var document = new Aspose.Pdf.Document())
    {
        // Add page
        var page = document.Pages.Add();
        var latex = new Aspose.Pdf.TeXFragment(s);
        page.Paragraphs.Add(latex);
        // Save PDF document
        document.Save(dataDir + "Script_out.pdf");
    }
}