Master Slide

Master slides form the top level of the slide inheritance hierarchy in PowerPoint. A master slide defines common design elements such as backgrounds, logos, and text formatting. Layout slides inherit from master slides, and normal slides inherit from layout slides.

This article demonstrates how to create, modify, and manage master slides using Aspose.Slides for C++.

Add a Master Slide

This example shows how to create a new master slide by cloning the default one. It then adds a company name banner to all slides through layout inheritance.

static void AddMasterSlide()
{
    auto presentation = MakeObject<Presentation>();

    // Clone the default master slide.
    auto defaultMasterSlide = presentation->get_Master(0);
    auto newMasterSlide = presentation->get_Masters()->AddClone(defaultMasterSlide);

    // Add a banner with company name to the top of the master slide.
    auto textBox = newMasterSlide->get_Shapes()->AddAutoShape(ShapeType::Rectangle, 0, 0, 720, 25);
    textBox->get_TextFrame()->set_Text(u"Company Name");
    auto paragraph = textBox->get_TextFrame()->get_Paragraph(0);
    auto textFormat = paragraph->get_ParagraphFormat()->get_DefaultPortionFormat();
    textFormat->get_FillFormat()->set_FillType(FillType::Solid);
    textFormat->get_FillFormat()->get_SolidFillColor()->set_Color(Color::get_Black());
    textBox->get_FillFormat()->set_FillType(FillType::NoFill);

    // Assign the new master slide to a layout slide.
    auto layoutSlide = presentation->get_LayoutSlide(0);
    layoutSlide->set_MasterSlide(newMasterSlide);

    // Assign the layout slide to the first slide in the presentation.
    presentation->get_Slide(0)->set_LayoutSlide(layoutSlide);

    presentation->Dispose();
}

💡 Note 1: Master slides provide a way to apply consistent branding or shared design elements across all slides. Any changes made to the master will automatically reflect on dependent layout and normal slides.

💡 Note 2: Any shapes or formatting added to a master slide are inherited by layout slides and, in turn, all normal slides using those layouts. The image below illustrates how a text box added on a master slide is automatically rendered on the final slide.

Access a Master Slide

You can access master slides using the presentation master collection. Here’s how to retrieve and work with them:

static void AccessMasterSlide()
{
    auto presentation = MakeObject<Presentation>();

    auto firstMasterSlide = presentation->get_Master(0);

    // Change the background type.
    firstMasterSlide->get_Background()->set_Type(BackgroundType::OwnBackground);

    presentation->Dispose();
}

Remove a Master Slide

Master slides can be removed either by index or by reference.

static void RemoveMasterSlide()
{
    auto presentation = MakeObject<Presentation>(u"sample.pptx");

    // Remove a master slide by index.
    presentation->get_Masters()->RemoveAt(0);

    // Remove a master slide by reference.
    auto firstMasterSlide = presentation->get_Master(0);
    presentation->get_Masters()->Remove(firstMasterSlide);

    presentation->Dispose();
}

Remove Unused Master Slides

Some presentations contain master slides that are not in use. Removing these slides can help reduce file size.

static void RemoveUnusedMasterSlide()
{
    auto presentation = MakeObject<Presentation>();

    // Remove all unused master slides (even those marked as Preserve).
    presentation->get_Masters()->RemoveUnused(true);

    presentation->Dispose();
}