Automate Presentation Localization in .NET

Change Language for Presentation and Shape’s Text

• Create an instance of Presentation class.
• Obtain the reference of a slide by using its Index.
• Add an AutoShape of Rectangle type to the slide.
• Add some text to the TextFrame.
• Setting Language Id to text.
• Write the presentation as a PPTX file.

The implementation of the above steps is demonstrated below in an example.

using (Presentation pres = new Presentation("test0.pptx"))
{
    IAutoShape shape = pres.Slides[0].Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 200, 50);
    shape.AddTextFrame("Text to apply spellcheck language");
    shape.TextFrame.Paragraphs[0].Portions[0].PortionFormat.LanguageId = "en-EN";

    pres.Save("test1.pptx",Aspose.Slides.Export.SaveFormat.Pptx);
}

FAQ

Does language ID trigger automatic text translation?

No. LanguageId in Aspose.Slides stores the language for spell-checking and grammar proofing, but it does not translate or change the text content. It is metadata that PowerPoint understands for proofing.

Does language ID affect hyphenation and line breaks during rendering?

In Aspose.Slides, LanguageId is for proofing. Hyphenation quality and line wrapping primarily depend on the availability of proper fonts and layout/line-break settings for the writing system. To ensure correct rendering, make the required fonts available, configure font substitution rules, and/or embed fonts into the presentation.

Can I set different languages within a single paragraph?

Yes. LanguageId is applied at the text portion level, so a single paragraph can mix multiple languages with distinct proofing settings.