Extract text from Microsoft Office PowerPoint presentations

To extract a text from Microsoft Office PowerPoint presentations GetText and GetText(pageIndex) method is used. These methods allow to extract a text from the entire presentation or a text from the selected slide.

Here are the steps to extract a text from Microsoft Office PowerPoint presentations:

Instantiate Parser object for the initial presentation;
Call GetText method and obtain TextReader object;
Read a text from reader.

GetText method returns null value if text extraction isn’t supported for the document. For example, text extraction isn’t supported for Zip archive. Therefore, for Zip archive GetText method returns null. For empty Microsoft Office PowerPoint presentations GetText method returns an empty TextReader object (reader.ReadToEnd method returns an empty string).

The following example demonstrates how to extract a text from Microsoft Office PowerPoint presentation:

// Create an instance of Parser class
using(Parser parser = new Parser(filePath))
{
    // Extract a text into the reader
    using(TextReader reader = parser.GetText())
    {
        // Print a text from the presentation
        Console.WriteLine(reader.ReadToEnd());
    }
}

Here are the steps to extract a text from the sheet of Microsoft Office PowerPoint presentation:

Instantiate Parser object for the initial presentation;
Call GetDocumentInfo method and obtain IDocumentInfo object with page count;
Call GetText(pageIndex) method with the sheet index and obtain TextReader object;
Read a text from reader.

The following example demonstrates how to extract a text from the slide of Microsoft Office PowerPoint presentation:

// Create an instance of Parser class
using(Parser parser = new Parser(filePath))
{
    // Get the document info
    IDocumentInfo documentInfo = parser.GetDocumentInfo();
    
    // Iterate over slides
    for(int p = 0; p < documentInfo.PageCount; p++)
    {
        // Print a page number 
        Console.WriteLine(string.Format("Slide {0}/{1}", p + 1, documentInfo.PageCount));
    
        // Extract a text into the reader
        using(TextReader reader = parser.GetText(p))
        {
            // Print a text from the presentation slide
            Console.WriteLine(reader.ReadToEnd());
        }
    }
}

Raw mode allows to increase the speed of text extraction due to poor formatting accuracy. GetText(TextOptions) and GetText(pageIndex, TextOptions) methods are used to extract a text in raw mode.

Raw mode is not supported for password-protected presentations.

Some presentations may have different slide numbers in raw and accurate modes. Use DocumentInfo.RawPageCount instead of IDocumentInfo.PageCount in raw mode.

Here are the steps to extract a raw text from the sheet of Microsoft Office PowerPoint presentation:

Instantiate Parser object for the initial presentation;
Instantiate TextOptions object with true parameter;
Call GetDocumentInfo method and cast the result to DocumentInfo class;
Use RawPageCount instead of PageCount to avoid extra calculations;
Call GetText(pageIndex, TextOptions) method with the sheet index and obtain TextReader object;
Read a text from reader.

The following example demonstrates how to extract a raw text from the slide of Microsoft Office PowerPoint presentation:

// Create an instance of Parser class
using (Parser parser = new Parser(filePath))
{
    // Get the document info
    DocumentInfo documentInfo = parser.GetDocumentInfo() as DocumentInfo;
    // Check if the document has slides
    if (documentInfo == null || documentInfo.RawPageCount == 0)
    {
        Console.WriteLine("Document hasn't pages.");
        return;
    }
    // Iterate over slides
    for (int p = 0; p < documentInfo.RawPageCount; p++)
    {
        // Print a slide number 
        Console.WriteLine(string.Format("Slide {0}/{1}", p + 1, documentInfo.RawPageCount));
        // Extract a text into the reader
        using (TextReader reader = parser.GetText(p, new TextOptions(true)))
        {
            // Print a text from the presentation slide
            Console.WriteLine(reader.ReadToEnd());
        }
    }
}

GroupDocs.Parser also allows to extract a text from Microsoft Office PowerPoint presentations as HTML, Markdown and formatted plain text. For more details, see Extract Formatted Text.

Here are the steps to extract a text from Microsoft Office PowerPoint presentation as HTML:

Instantiate Parser object for the initial presentation;
Call GetFormattedText method and obtain TextReader object;
Read a text from reader.

The following example shows how to extract a text from Microsoft Office PowerPoint presentation as HTML:

// Create an instance of Parser class
using (Parser parser = new Parser(filePath))
{
    // Extract a formatted text into the reader
    using (TextReader reader = parser.GetFormattedText(new FormattedTextOptions(FormattedTextMode.Html)))
    {
        // Print a formatted text from the presentation
        Console.WriteLine(reader.ReadToEnd());
    }
}

More resources

GitHub examples

You may easily run the code above and see the feature in action in our GitHub examples:

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