Edytuj

Udostępnij za pośrednictwem

Set the font for a text run

  • Artykuł

This topic shows how to use the classes in the Open XML SDK for Office to set the font for a portion of text within a word processing document programmatically.

Packages and Document Parts

An Open XML document is stored as a package, whose format is defined by ISO/IEC 29500. The package can have multiple parts with relationships between them. The relationship between parts controls the category of the document. A document can be defined as a word-processing document if its package-relationship item contains a relationship to a main document part. If its package-relationship item contains a relationship to a presentation part it can be defined as a presentation document. If its package-relationship item contains a relationship to a workbook part, it is defined as a spreadsheet document. In this how-to topic, you will use a word-processing document package.

Structure of the Run Fonts Element

The following text from the ISO/IEC 29500 specification can be useful when working with rFonts element.

This element specifies the fonts which shall be used to display the text contents of this run. Within a single run, there may be up to four types of content present which shall each be allowed to use a unique font:

  • ASCII

  • High ANSI

  • Complex Script

  • East Asian

The use of each of these fonts shall be determined by the Unicode character values of the run content, unless manually overridden via use of the cs element.

If this element is not present, the default value is to leave the formatting applied at previous level in the style hierarchy. If this element is never applied in the style hierarchy, then the text shall be displayed in any default font which supports each type of content.

Consider a single text run with both Arabic and English text, as follows:

English العربية

This content may be expressed in a single WordprocessingML run:

    <w:r>
      <w:t>English العربية</w:t>
    </w:r>

Although it is in the same run, the contents are in different font faces by specifying a different font for ASCII and CS characters in the run:

    <w:r>
      <w:rPr>
        <w:rFonts w:ascii="Courier New" w:cs="Times New Roman" />
      </w:rPr>
      <w:t>English العربية</w:t>
    </w:r>

This text run shall therefore use the Courier New font for all characters in the ASCII range, and shall use the Times New Roman font for all characters in the Complex Script range.

© ISO/IEC 29500: 2016

How the Sample Code Works

After opening the package file for read/write, the code creates a RunProperties object that contains a RunFonts object that has its Ascii property set to "Arial". RunProperties and RunFonts objects represent run properties rPr elements and run fonts elements rFont, respectively, in the Open XML Wordprocessing schema. Use a RunProperties object to specify the properties of a given text run. In this case, to set the font of the run to Arial, the code creates a RunFonts object and then sets the Ascii value to "Arial".

// Set the font to Arial to the first Run.
// Use an object initializer for RunProperties and rPr.
RunProperties rPr = new RunProperties(
    new RunFonts()
    {
        Ascii = "Arial"
    });

The code then creates a Run object that represents the first text run of the document. The code instantiates a Run and sets it to the first text run of the document. The code then adds the RunProperties object to the Run object using the PrependChild method. The PrependChild method adds an element as the first child element to the specified element in the in-memory XML structure. In this case, running the code sample produces an in-memory XML structure where the RunProperties element is added as the first child element of the Run element. There is no need to call Save directly, because we are inside of a using statement.

if (package.MainDocumentPart is null)
{
    throw new ArgumentNullException("MainDocumentPart is null.");
}

Run r = package.MainDocumentPart.Document.Descendants<Run>().First();
r.PrependChild<RunProperties>(rPr);

Note

This code example assumes that the test word processing document at fileName path contains at least one text run.

The following is the complete sample code in both C# and Visual Basic.

static void SetRunFont(string fileName)
{
    // Open a Wordprocessing document for editing.
    using (WordprocessingDocument package = WordprocessingDocument.Open(fileName, true))
    {
        // Set the font to Arial to the first Run.
        // Use an object initializer for RunProperties and rPr.
        RunProperties rPr = new RunProperties(
            new RunFonts()
            {
                Ascii = "Arial"
            });

        if (package.MainDocumentPart is null)
        {
            throw new ArgumentNullException("MainDocumentPart is null.");
        }

        Run r = package.MainDocumentPart.Document.Descendants<Run>().First();
        r.PrependChild<RunProperties>(rPr);
    }
}

See also