Manage Drawing Guides in Presentations in .NET

Overview

Drawing guides are adjustable horizontal and vertical lines that help users align shapes consistently while editing a presentation in PowerPoint. They are especially useful when an application generates a presentation that will later be refined manually: the application can save the same alignment aids that authors should follow when adding or moving content.

Drawing guides are editing aids, not slide content. They do not appear in a slide show or rendered output. Aspose.Slides for .NET exposes them through the IDrawingGuidesCollection interface. A guide is represented by IDrawingGuide and has an orientation, a position, and a color.

The position is measured in points from the top-left corner of the relevant slide or master. A vertical guide uses a horizontal coordinate, typically between zero and the slide width. A horizontal guide uses a vertical coordinate, typically between zero and the slide height.

Add Guides to the Slide View

Use ICommonSlideViewProperties.DrawingGuides to manage guides displayed while editing normal slides. Call IDrawingGuidesCollection.Add with an Orientation value and a position in points.

The following example adds one vertical guide to the right of the slide center and one horizontal guide below it:

using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();

var slideSize = presentation.SlideSize.Size;
var guides = presentation.ViewProperties.SlideViewProperties.DrawingGuides;

guides.Add(Orientation.Vertical, slideSize.Width / 2 + 12.5f);
guides.Add(Orientation.Horizontal, slideSize.Height / 2 + 12.5f);

presentation.Save("drawing-guides.pptx", SaveFormat.Pptx);

Access Drawing Guides

The IDrawingGuidesCollection.Count property and indexer provide access to existing guides. The IDrawingGuide.Orientation, IDrawingGuide.Position, and IDrawingGuide.Color properties can be read or changed.

The following example reads the slide-view guides from the presentation created above:

using Aspose.Slides;

using var presentation = new Presentation("drawing-guides.pptx");

var guides = presentation.ViewProperties.SlideViewProperties.DrawingGuides;

for (var index = 0; index < guides.Count; index++)
{
    var guide = guides[index];
    Console.WriteLine($"Guide {index}: orientation = {guide.Orientation}, position = {guide.Position}, color = {guide.Color}");
}

Add Guides to Master and Layout Slides

A slide master and each of its layout slides can have their own drawing-guide collections. Use IMasterSlide.DrawingGuides for a master slide and ILayoutSlide.DrawingGuides for a layout slide.

The following example adds a vertical guide to the first master slide and a horizontal guide to the first layout slide:

using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();

var slideSize = presentation.SlideSize.Size;
var masterGuides = presentation.Masters[0].DrawingGuides;
var layoutGuides = presentation.LayoutSlides[0].DrawingGuides;

masterGuides.Add(Orientation.Vertical, slideSize.Width / 2 - 20f);
layoutGuides.Add(Orientation.Horizontal, slideSize.Height / 2 + 20f);

presentation.Save("master-layout-drawing-guides.pptx", SaveFormat.Pptx);

Add Guides to Notes and Handout Masters

Notes masters and handout masters also support drawing guides. Use IMasterNotesSlide.DrawingGuides and IMasterHandoutSlide.DrawingGuides to access their collections. If a presentation does not contain one of these masters, IMasterNotesSlideManager.SetDefaultMasterNotesSlide or IMasterHandoutSlideManager.SetDefaultMasterHandoutSlide creates the default master and returns it.

The following example adds a horizontal guide to a notes master and a vertical guide to a handout master:

using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();

var notesSize = presentation.NotesSize.Size;
var notesMaster = presentation.MasterNotesSlideManager.SetDefaultMasterNotesSlide();
var handoutMaster = presentation.MasterHandoutSlideManager.SetDefaultMasterHandoutSlide();

notesMaster.DrawingGuides.Add(Orientation.Horizontal, notesSize.Height / 2 + 50f);
handoutMaster.DrawingGuides.Add(Orientation.Vertical, notesSize.Width / 2 - 50f);

presentation.Save("notes-handout-drawing-guides.pptx", SaveFormat.Pptx);

Clear Drawing Guides

Call IDrawingGuidesCollection.Clear to remove every guide from a particular collection. Clearing one collection does not affect guides stored in another scope.

The following example clears the slide-view guides and all guides on slide masters, layout slides, the notes master, and the handout master without creating missing masters:

using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation("presentation-with-guides.pptx");

presentation.ViewProperties.SlideViewProperties.DrawingGuides.Clear();

foreach (var masterSlide in presentation.Masters)
{
    masterSlide.DrawingGuides.Clear();
}

foreach (var layoutSlide in presentation.LayoutSlides)
{
    layoutSlide.DrawingGuides.Clear();
}

var notesMaster = presentation.MasterNotesSlideManager.MasterNotesSlide;
if (notesMaster != null)
{
    notesMaster.DrawingGuides.Clear();
}

var handoutMaster = presentation.MasterHandoutSlideManager.MasterHandoutSlide;
if (handoutMaster != null)
{
    handoutMaster.DrawingGuides.Clear();
}

presentation.Save("presentation-without-guides.pptx", SaveFormat.Pptx);

FAQ

Do drawing guides appear in a slide show or exported images?

No. Drawing guides are alignment aids for editing and are not rendered as presentation content.

Can a drawing guide be added directly to an individual normal slide?

Normal-slide editing guides are stored in the presentation’s slide-view properties. Separate guide collections are available for slide masters, layout slides, notes masters, and handout masters.

Which units are used for guide positions?

Positions are specified in points, where 72 points equal one inch. Vertical positions are measured from the left edge, and horizontal positions are measured from the top edge.

Does clearing drawing guides remove shapes or change slide content?

No. The Clear method removes only the guides in the selected collection. Shapes and other slide content remain unchanged.

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