Format PowerPoint Shapes in C#

Overview

In PowerPoint, you can add shapes to slides. Since shapes are made up of lines, you can format them by modifying or applying effects to their outlines. Additionally, you can format shapes by specifying settings that control how their interiors are filled.

format-shape-powerpoint

Aspose.Slides for .NET provides interfaces and properties that allow you to format shapes using the same options available in PowerPoint.

Format Lines

Using Aspose.Slides, you can specify a custom line style for a shape. The following steps outline the procedure:

  1. Create an instance of the Presentation class.
  2. Get a reference to a slide by its index.
  3. Add an IAutoShape to the slide.
  4. Set the line style of the shape.
  5. Set the line width.
  6. Set the dash style of the shape.
  7. Set the line color for the shape.
  8. Save the modified presentation as a PPTX file.

This C# code demonstrates how to format a rectangle AutoShape:

// Instantiate the Presentation class that represents a presentation file.
using (Presentation presentation = new Presentation())
{
    // Get the first slide.
    ISlide slide = presentation.Slides[0];

    // Add an auto shape of the Rectangle type.
    IShape shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);

    // Set the fill color for the rectangle shape.
    shape.FillFormat.FillType = FillType.NoFill;

    // Apply formatting to the rectangle's lines.
    shape.LineFormat.Style = LineStyle.ThickThin;
    shape.LineFormat.Width = 7;
    shape.LineFormat.DashStyle = LineDashStyle.Dash;

    // Set the color for the rectangle's line.
    shape.LineFormat.FillFormat.FillType = FillType.Solid;
    shape.LineFormat.FillFormat.SolidFillColor.Color = Color.Blue;

    // Write the PPTX file to disk.
    presentation.Save("formatted_lines.pptx", SaveFormat.Pptx);
}

The result:

The formatted lines in the presentation

Format Join Styles

Here are the three join type options:

  • Round
  • Miter
  • Bevel

By default, when PowerPoint joins two lines at an angle (such as at a shape’s corner), it uses the Round setting. However, if you’re drawing a shape with sharp angles, you may prefer the Miter option.

The join style in the presentation

This C# code demonstrates how three rectangles (as shown in the image above) were created using the Miter, Bevel, and Round join type settings:

// Instantiate the Presentation class that represents a presentation file.
using (Presentation presentation = new Presentation())
{
    // Get the first slide.
    ISlide slide = presentation.Slides[0];

    // Add three auto shapes of the Rectangle type.
    IAutoShape shape1 = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 20, 20, 150, 75);
    IAutoShape shape2 = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 210, 20, 150, 75);
    IAutoShape shape3 = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 20, 135, 150, 75);

    // Set the fill color for each rectangle shape.
    shape1.FillFormat.FillType = FillType.Solid;
    shape1.FillFormat.SolidFillColor.Color = Color.Black;
    shape2.FillFormat.FillType = FillType.Solid;
    shape2.FillFormat.SolidFillColor.Color = Color.Black;
    shape3.FillFormat.FillType = FillType.Solid;
    shape3.FillFormat.SolidFillColor.Color = Color.Black;

    // Set the line width.
    shape1.LineFormat.Width = 15;
    shape2.LineFormat.Width = 15;
    shape3.LineFormat.Width = 15;

    // Set the color for each rectangle's line.
    shape1.LineFormat.FillFormat.FillType = FillType.Solid;
    shape1.LineFormat.FillFormat.SolidFillColor.Color = Color.Blue;
    shape2.LineFormat.FillFormat.FillType = FillType.Solid;
    shape2.LineFormat.FillFormat.SolidFillColor.Color = Color.Blue;
    shape3.LineFormat.FillFormat.FillType = FillType.Solid;
    shape3.LineFormat.FillFormat.SolidFillColor.Color = Color.Blue;

    // Set the join style.
    shape1.LineFormat.JoinStyle = LineJoinStyle.Miter;
    shape2.LineFormat.JoinStyle = LineJoinStyle.Bevel;
    shape3.LineFormat.JoinStyle = LineJoinStyle.Round;

    // Add text to each rectangle.
    shape1.TextFrame.Text = "Miter Join Style";
    shape2.TextFrame.Text = "Bevel Join Style";
    shape3.TextFrame.Text = "Round Join Style";

    // Write the PPTX file to disk.
    presentation.Save("join_styles.pptx", SaveFormat.Pptx);
}

Gradient Fill

In PowerPoint, Gradient Fill is a formatting option that allows you to apply a continuous blend of colors to a shape. For example, you can apply two or more colors in a way that one gradually fades into another.

Here’s how to apply a gradient fill to a shape using Aspose.Slides:

  1. Create an instance of the Presentation class.
  2. Get a reference to a slide by its index.
  3. Add an IAutoShape to the slide.
  4. Set the shape’s FillType to Gradient.
  5. Add your two preferred colors with defined positions using the Add methods of the GradientStops collection exposed by the GradientFormat class.
  6. Save the modified presentation as a PPTX file.

The following C# code demonstrates how to apply a gradient fill effect to an ellipse:

// Instantiate the Presentation class that represents a presentation file.
using (Presentation presentation = new Presentation())
{
    // Get the first slide.
    ISlide slide = presentation.Slides[0];

    // Add an auto shape of the Ellipse type.
    IShape shape = slide.Shapes.AddAutoShape(ShapeType.Ellipse, 50, 50, 150, 75);

    // Apply gradient formatting to the ellipse.
    shape.FillFormat.FillType = FillType.Gradient;
    shape.FillFormat.GradientFormat.GradientShape = GradientShape.Linear;

    // Set the direction of the gradient.
    shape.FillFormat.GradientFormat.GradientDirection = GradientDirection.FromCorner2;

    // Add two gradient stops.
    shape.FillFormat.GradientFormat.GradientStops.Add(1.0f, PresetColor.Purple);
    shape.FillFormat.GradientFormat.GradientStops.Add(0.0f, PresetColor.Red);

    // Write the PPTX file to disk.
    presentation.Save("gradient_fill.pptx", SaveFormat.Pptx);
}

The result:

The ellipse with gradient fill

Pattern Fill

In PowerPoint, Pattern Fill is a formatting option that lets you apply a two-color design—such as dots, stripes, crosshatches, or checks—to a shape. You can choose custom colors for the pattern’s foreground and background.

Aspose.Slides provides over 45 predefined pattern styles that you can apply to shapes to enhance the visual appeal of your presentations. Even after selecting a predefined pattern, you can still specify the exact colors it should use.

Here’s how to apply a pattern fill to a shape using Aspose.Slides:

  1. Create an instance of the Presentation class.
  2. Get a reference to a slide by its index.
  3. Add an IAutoShape to the slide.
  4. Set the shape’s FillType to Pattern.
  5. Choose a pattern style from the predefined options.
  6. Set the Background Color of the pattern.
  7. Set the Foreground Color of the pattern.
  8. Save the modified presentation as a PPTX file.

The following C# code demonstrates how to apply a pattern fill to a rectangle:

// Instantiate the Presentation class that represents a presentation file.
using (Presentation presentation = new Presentation())
{
    // Get the first slide.
    ISlide slide = presentation.Slides[0];

    // Add an auto shape of the Rectangle type.
    IShape shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);

    // Set the fill type to Pattern.
    shape.FillFormat.FillType = FillType.Pattern;

    // Set the pattern style.
    shape.FillFormat.PatternFormat.PatternStyle = PatternStyle.Trellis;

    // Set the pattern background and foreground colors.
    shape.FillFormat.PatternFormat.BackColor.Color = Color.LightGray;
    shape.FillFormat.PatternFormat.ForeColor.Color = Color.Yellow;

    // Write the PPTX file to disk.
    presentation.Save("pattern_fill.pptx", SaveFormat.Pptx);
}

The result:

The rectangle with pattern fill

Picture Fill

In PowerPoint, Picture Fill is a formatting option that allows you to insert an image inside a shape—effectively using the image as the shape’s background.

Here’s how to use Aspose.Slides to apply a picture fill to a shape:

  1. Create an instance of the Presentation class.
  2. Get a reference to a slide by its index.
  3. Add an IAutoShape to the slide.
  4. Set the shape’s FillType to Picture.
  5. Set the picture fill mode to Tile (or another preferred mode).
  6. Create an IPPImage object from the image you want to use.
  7. Assign this image to the Picture.Image property of the shape’s PictureFillFormat.
  8. Save the modified presentation as a PPTX file.

Let’s say we have a “lotus.png” file with the following picture:

The lotus picture

The following C# code demonstrates how to fill a shape with the picture:

// Instantiate the Presentation class that represents a presentation file.
using (Presentation presentation = new Presentation())
{
    // Get the first slide.
    ISlide slide = presentation.Slides[0];

    // Add an auto shape of the Rectangle type.
    IShape shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 192, 95);

    // Set the fill type to Picture.
    shape.FillFormat.FillType = FillType.Picture;

    // Set the picture fill mode.
    shape.FillFormat.PictureFillFormat.PictureFillMode = PictureFillMode.Tile;

    // Load an image and add it to the presentation resources.
    IImage image = Images.FromFile("lotus.png");
    IPPImage presentationImage = presentation.Images.AddImage(image);
    image.Dispose();

    // Set the picture.
    shape.FillFormat.PictureFillFormat.Picture.Image = presentationImage;

    // Write the PPTX file to disk.
    presentation.Save("picture_fill.pptx", SaveFormat.Pptx);
}

The result:

The shape with picture fill

Tile Picture As Texture

If you want to set a tiled picture as a texture and customize the tiling behavior, you can use the following properties of the IPictureFillFormat interface and PictureFillFormat class:

  • PictureFillMode: Sets the picture fill mode—either Tile or Stretch.
  • TileAlignment: Specifies the alignment of the tiles within the shape.
  • TileFlip: Controls whether the tile is flipped horizontally, vertically, or both.
  • TileOffsetX: Sets the horizontal offset of the tile (in points) from the shape’s origin.
  • TileOffsetY: Sets the vertical offset of the tile (in points) from the shape’s origin.
  • TileScaleX: Defines the horizontal scale of the tile as a percentage.
  • TileScaleY: Defines the vertical scale of the tile as a percentage.

The following code sample shows how to add a rectangle shape with a tiled picture fill and configure tile options:

// Instantiate the Presentation class that represents a presentation file.
using (Presentation presentation = new Presentation())
{
    // Get the first slide.
    ISlide firstSlide = presentation.Slides[0];

    // Load the image and add it to the presentation resources.
    IPPImage presentationImage;
    using (IImage sourceImage = Images.FromFile("lotus.png"))
        presentationImage = presentation.Images.AddImage(sourceImage);

    // Add a rectangle auto shape.
    IShape shape = firstSlide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 185, 90);

    // Set the fill type of the shape to Picture.
    shape.FillFormat.FillType = FillType.Picture;

    // Assign the image to the shape.
    IPictureFillFormat pictureFillFormat = shape.FillFormat.PictureFillFormat;
    pictureFillFormat.Picture.Image = presentationImage;

    // Configure the picture fill mode and tiling properties.
    pictureFillFormat.PictureFillMode = PictureFillMode.Tile;
    pictureFillFormat.TileOffsetX = -32;
    pictureFillFormat.TileOffsetY = -32;
    pictureFillFormat.TileScaleX = 50;
    pictureFillFormat.TileScaleY = 50;
    pictureFillFormat.TileAlignment = RectangleAlignment.BottomRight;
    pictureFillFormat.TileFlip = TileFlip.FlipBoth;

    // Write the PPTX file to disk.
    presentation.Save("tile.pptx", SaveFormat.Pptx);
}

The result:

The tile options

Solid Color Fill

In PowerPoint, Solid Color Fill is a formatting option that fills a shape with a single, uniform color. This plain background color is applied without any gradients, textures, or patterns.

To apply a solid color fill to a shape using Aspose.Slides, follow these steps:

  1. Create an instance of the Presentation class.
  2. Get a reference to a slide by its index.
  3. Add an IAutoShape to the slide.
  4. Set the shape’s FillType to Solid.
  5. Assign your preferred fill color to the shape.
  6. Save the modified presentation as a PPTX file.

The following C# code demonstrates how to apply a solid color fill to a rectangle in a PowerPoint slide:

// Instantiate the Presentation class that represents a presentation file.
using (Presentation presentation = new Presentation())
{
    // Get the first slide.
    ISlide slide = presentation.Slides[0];

    // Add an auto shape of the Rectangle type.
    IShape shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);

    // Set the fill type to Solid.
    shape.FillFormat.FillType = FillType.Solid;

    // Set the fill color.
    shape.FillFormat.SolidFillColor.Color = Color.Yellow;

    // Write the PPTX file to disk.
    presentation.Save("solid_color_fill.pptx", SaveFormat.Pptx);
}

The result:

The shape with solid color fill

Set Transparency

In PowerPoint, when you apply a solid color, gradient, picture, or texture fill to shapes, you can also set a transparency level to control the opacity of the fill. A higher transparency value makes the shape more see-through, allowing the background or underlying objects to be partially visible.

Aspose.Slides lets you set the transparency level by adjusting the alpha value in the color used for the fill. Here’s how to do it:

  1. Create an instance of the Presentation class.
  2. Get a reference to a slide by its index.
  3. Add an IAutoShape to the slide.
  4. Set the fill type to Solid.
  5. Use Color.FromArgb(alpha, baseColor) to define a color with transparency (the alpha component controls transparency).
  6. Save the presentation.

This C# code demonstrates how to apply a transparent fill color to a rectangle:

const int alpha = 128;

// Instantiate the Presentation class that represents a presentation file.
using (Presentation presentation = new Presentation())
{
    // Get the first slide.
    ISlide slide = presentation.Slides[0];

    // Add a solid rectangle auto shape.
    IShape solidShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);

    // Add a transparent rectangle auto shape over the solid shape.
    IShape transparentShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 80, 80, 150, 75);
    transparentShape.FillFormat.FillType = FillType.Solid;
    transparentShape.FillFormat.SolidFillColor.Color = Color.FromArgb(alpha, Color.Yellow);

    // Write the PPTX file to disk.
    presentation.Save("shape_transparency.pptx", SaveFormat.Pptx);
}

The result:

The transparent shape

Rotate Shapes

Aspose.Slides lets you rotate shapes in PowerPoint presentations. This can be useful when positioning visual elements with specific alignment or design needs.

To rotate a shape on a slide, follow these steps:

  1. Create an instance of the Presentation class.
  2. Get a reference to a slide by its index..
  3. Add an IAutoShape to the slide.
  4. Set the shape’s Rotation property to the desired angle.
  5. Save the presentation.

This C# code demonstrates how to rotate a shape by 5 degrees:

// Instantiate the Presentation class that represents a presentation file.
using (Presentation presentation = new Presentation())
{
    // Get the first slide.
    ISlide slide = presentation.Slides[0];

    // Add an auto shape of the Rectangle type.
    IShape shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);

    // Rotate the shape by 5 degrees.
    shape.Rotation = 5;

    // Write the PPTX file to disk.
    presentation.Save("shape_rotation.pptx", SaveFormat.Pptx);
}

The result:

The shape rotation

Add 3D Bevel Effects

Aspose.Slides allows you to apply 3D bevel effects to shapes by configuring their ThreeDFormat properties.

To add 3D bevel effects to a shape, follow these steps:

  1. Instantiate the Presentation class.
  2. Get a reference to a slide by its index.
  3. Add an IAutoShape to the slide.
  4. Configure the shape’s ThreeDFormat to define bevel settings.
  5. Save the presentation.

This C# code shows how to apply 3D bevel effects to a shape:

// Create an instance of the Presentation class.
using (Presentation presentation = new Presentation())
{
    ISlide slide = presentation.Slides[0];

    // Add a shape to the slide.
    IAutoShape shape = slide.Shapes.AddAutoShape(ShapeType.Ellipse, 50, 50, 100, 100);
    shape.FillFormat.FillType = FillType.Solid;
    shape.FillFormat.SolidFillColor.Color = Color.Green;
    shape.LineFormat.FillFormat.FillType = FillType.Solid;
    shape.LineFormat.FillFormat.SolidFillColor.Color = Color.Orange;
    shape.LineFormat.Width = 2.0;

    // Set the shape's ThreeDFormat properties.
    shape.ThreeDFormat.Depth = 4;
    shape.ThreeDFormat.BevelTop.BevelType = BevelPresetType.Circle;
    shape.ThreeDFormat.BevelTop.Height = 6;
    shape.ThreeDFormat.BevelTop.Width = 6;
    shape.ThreeDFormat.Camera.CameraType = CameraPresetType.OrthographicFront;
    shape.ThreeDFormat.LightRig.LightType = LightRigPresetType.ThreePt;
    shape.ThreeDFormat.LightRig.Direction = LightingDirection.Top;

    // Write the presentation as a PPTX file.
    presentation.Save("3D_bevel_effect.pptx", SaveFormat.Pptx);
}

The result:

The 3D bevel effect

Add 3D Rotation Effect

Aspose.Slides allows you to apply 3D rotation effects to shapes by configuring their ThreeDFormat properties.

To apply 3D rotation to a shape:

  1. Create an instance of the Presentation class.
  2. Get a reference to a slide by its index.
  3. Add an IAutoShape to the slide.
  4. Set the shape’s CameraType and LightType to define the 3D rotation.
  5. Save the presentation.

This C# code demonstrates how to apply 3D rotation effects to a shape:

// Create an instance of the Presentation class.
using (Presentation presentation = new Presentation())
{
    ISlide slide = presentation.Slides[0];

    IAutoShape autoShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);
    autoShape.TextFrame.Text = "Hello, Aspose!";

    autoShape.ThreeDFormat.Depth = 6;
    autoShape.ThreeDFormat.Camera.SetRotation(40, 35, 20);
    autoShape.ThreeDFormat.Camera.CameraType = CameraPresetType.IsometricLeftUp;
    autoShape.ThreeDFormat.LightRig.LightType = LightRigPresetType.Balanced;

    // Write the presentation as a PPTX file.
    presentation.Save("3D_rotation_effect.pptx", SaveFormat.Pptx);
}

The result:

The 3D rotation effect

Reset Formatting

This C# code shows how to reset the formatting of a slide and revert the position, size, and formatting of all shapes with placeholders on the LayoutSlide to their default settings:

using (Presentation presentation = new Presentation())
{
    foreach (ISlide slide in presentation.Slides)
    {
        // Revert each shape on the slide that has a placeholder on the layout.
        slide.Reset();
    }
}

FAQs

Does shape formatting affect the final presentation file size?

Only minimally. Embedded images and media occupy most of the file space, while shape parameters such as colors, effects, and gradients are stored as metadata and add virtually no extra size.

How can I detect shapes on a slide that share identical formatting so I can group them?

Compare each shape’s key formatting properties—fill, line, and effect settings. If all corresponding values match, treat their styles as identical and logically group those shapes, which simplifies later style management.

Can I save a set of custom shape styles to a separate file for reuse in other presentations?

Yes. Store sample shapes with the desired styles in a template slide deck or a .POTX template file. When creating a new presentation, open the template, clone the styled shapes you need, and re‑apply their formatting wherever required.

Shape Types Apply Shape Effects in PowerPoint Using C#