Format PowerPoint Shapes in .NET

What this page is about

Learn how to format PowerPoint shapes in C# using Aspose.Slides—set fill, line, and effect styles for PPT and PPTX files with precision and full control.

Introduction

Format shapes in PowerPoint by adjusting their outlines, fills, and effects. Aspose.Slides for .NET lets you control these settings programmatically, including transparency, rotation, and 3D formatting.

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

Format Lines

Use IShape.LineFormat to control a shape’s outline. This example creates an unfilled rectangle with a blue, dashed outline. ILineFormat.Style selects a thick-thin compound line, while ILineFormat.Width sets its width to 7 points and ILineFormat.DashStyle selects the dash pattern.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);
shape.FillFormat.FillType = FillType.NoFill;
shape.LineFormat.Style = LineStyle.ThickThin;
shape.LineFormat.Width = 7;
shape.LineFormat.DashStyle = LineDashStyle.Dash;
shape.LineFormat.FillFormat.FillType = FillType.Solid;
shape.LineFormat.FillFormat.SolidFillColor.Color = Color.Blue;

presentation.Save("formatted_lines.pptx", SaveFormat.Pptx);

The result:

Set Custom Line Dash Patterns

Use ILineFormat.CustomDashPattern when predefined line styles do not provide the dash lengths and gaps you need, for example for branded outlines or technical diagrams. Assigning a pattern automatically sets ILineFormat.DashStyle to LineDashStyle.Custom.

Array entries alternate between dash and gap lengths, starting with a dash. Each value is a multiple of the line width: { 4, 2 } at a width of 3 points produces a 12-point dash followed by a 6-point gap. Use pairs of finite, nonnegative values to define complete dash-and-gap segments. The example uses positive values to keep every dash and gap visible.

This example creates five blue lines with the same length and flat caps. The first three compare patterns at a width of 3 points. The fourth repeats the first pattern at twice the width, doubling both the dash and gap lengths. The fifth switches from a custom pattern to a solid line.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
presentation.SlideSize.SetSize(600, 300, SlideSizeScaleType.DoNotScale);
var slide = presentation.Slides[0];

var patterns = new[]
{
    new float[] { 4, 2 },
    new float[] { 1, 2 },
    new float[] { 6, 2, 1, 2 },
    new float[] { 4, 2 },
    new float[] { 4, 2 }
};

for (var i = 0; i < patterns.Length; i++)
{
    var line = slide.Shapes.AddAutoShape(ShapeType.Line, 50, 50 + i * 50, 500, 0);
    line.LineFormat.Width = i == 3 ? 6 : 3;
    line.LineFormat.FillFormat.FillType = FillType.Solid;
    line.LineFormat.FillFormat.SolidFillColor.Color = Color.DarkBlue;
    line.LineFormat.CapStyle = LineCapStyle.Flat;
    line.LineFormat.BeginArrowheadStyle = LineArrowheadStyle.None;
    line.LineFormat.EndArrowheadStyle = LineArrowheadStyle.None;
    line.LineFormat.CustomDashPattern = patterns[i];
}

// Return the last line to a solid style.
slide.Shapes[4].LineFormat.DashStyle = LineDashStyle.Solid;

presentation.Save("custom_dash_patterns.pptx", SaveFormat.Pptx);

To return to a predefined dashed style instead, assign LineDashStyle.Dash to ILineFormat.DashStyle. The selected style controls the line’s appearance.

The result in PowerPoint, from top to bottom: {4, 2}, 3 pt; {1, 2}, 3 pt; {6, 2, 1, 2}, 3 pt; {4, 2}, 6 pt; and Solid, 3 pt.

Set Line Caps

Use ILineFormat.CapStyle to set the ends of an open line. The LineCapStyle enumeration provides three explicit cap styles:

• Flat: The stroke stops at the endpoint.
• Round: A semicircular cap extends beyond the endpoint by half the line width.
• Square: A square cap extends beyond the endpoint by half the line width.

The enumeration also includes NotDefined, which means that no cap style is explicitly assigned.

Caps are different from arrowheads, which add symbols to line ends, and joins, which control corners between line segments. This example disables arrowheads through ILineFormat.BeginArrowheadStyle and ILineFormat.EndArrowheadStyle so that only the cap shapes are compared.

The following example creates three otherwise identical horizontal lines, 20 points wide. From top to bottom, they use flat, round, and square caps. Their endpoints have the same horizontal coordinates; the round and square caps extend 10 points beyond each endpoint.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
presentation.SlideSize.SetSize(500, 240, SlideSizeScaleType.DoNotScale);
var slide = presentation.Slides[0];

var capStyles = new[] { LineCapStyle.Flat, LineCapStyle.Round, LineCapStyle.Square };

for (var i = 0; i < capStyles.Length; i++)
{
    var line = slide.Shapes.AddAutoShape(ShapeType.Line, 100, 50 + i * 70, 300, 0);
    line.LineFormat.Width = 20;
    line.LineFormat.FillFormat.FillType = FillType.Solid;
    line.LineFormat.FillFormat.SolidFillColor.Color = Color.DarkBlue;
    line.LineFormat.DashStyle = LineDashStyle.Solid;
    line.LineFormat.CapStyle = capStyles[i];
    line.LineFormat.BeginArrowheadStyle = LineArrowheadStyle.None;
    line.LineFormat.EndArrowheadStyle = LineArrowheadStyle.None;
}

presentation.Save("line_caps.pptx", SaveFormat.Pptx);

The result in PowerPoint, from top to bottom: Flat, Round, and Square.

Apply Sketch Effects to Shape Lines

A sketch effect makes a shape line look hand-drawn. Use IShape.LineFormat to access the line settings, ILineFormat.SketchFormat to access the sketch settings, and ISketchFormat.SketchType to select a value from the LineSketchType enumeration.

The following C# code shows how to apply a LineSketchType.Curved effect, read the explicitly assigned value, and remove the effect with LineSketchType.None:

using System;
using Aspose.Slides;

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 200, 100);

var sketchFormat = shape.LineFormat.SketchFormat;
sketchFormat.SketchType = LineSketchType.Curved;
var explicitSketchType = sketchFormat.SketchType;
Console.WriteLine($"Explicit sketch type: {explicitSketchType}");
sketchFormat.SketchType = LineSketchType.None;

The value returned by ISketchFormat.SketchType represents the setting assigned directly to the shape. If the line formatting can be inherited from a theme, master slide, or layout slide, use ILineFormat.GetEffective, access ILineFormatEffectiveData.SketchFormat, and read ISketchFormatEffectiveData.SketchType. The effective value reflects the formatting that is actually applied after inheritance is resolved. This example requires an existing presentation with at least one shape on its first slide and prints both values:

using System;
using Aspose.Slides;

using var presentation = new Presentation("presentation.pptx");
var shape = presentation.Slides[0].Shapes[0];

var lineFormat = shape.LineFormat;
var explicitSketchType = lineFormat.SketchFormat.SketchType;
var effectiveLineFormat = lineFormat.GetEffective();
var effectiveSketchType = effectiveLineFormat.SketchFormat.SketchType;

Console.WriteLine($"Explicit sketch type: {explicitSketchType}");
Console.WriteLine($"Effective sketch type: {effectiveSketchType}");

Format Join Styles

Here are the three join type options:

• Round
• Miter
• Bevel

The join style controls how two outline segments meet at a corner. Use Round for rounded corners, Miter for sharp corners, or Bevel for flattened corners.

This example creates three black rectangles with blue outlines 15 points wide. It sets ILineFormat.JoinStyle to the miter, bevel, and round values of LineJoinStyle, respectively, to compare how the corners are drawn.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var miterShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 20, 20, 150, 75);
var bevelShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 210, 20, 150, 75);
var roundShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 20, 135, 150, 75);

miterShape.FillFormat.FillType = FillType.Solid;
miterShape.FillFormat.SolidFillColor.Color = Color.Black;
bevelShape.FillFormat.FillType = FillType.Solid;
bevelShape.FillFormat.SolidFillColor.Color = Color.Black;
roundShape.FillFormat.FillType = FillType.Solid;
roundShape.FillFormat.SolidFillColor.Color = Color.Black;

miterShape.LineFormat.Width = 15;
bevelShape.LineFormat.Width = 15;
roundShape.LineFormat.Width = 15;

miterShape.LineFormat.FillFormat.FillType = FillType.Solid;
miterShape.LineFormat.FillFormat.SolidFillColor.Color = Color.Blue;
bevelShape.LineFormat.FillFormat.FillType = FillType.Solid;
bevelShape.LineFormat.FillFormat.SolidFillColor.Color = Color.Blue;
roundShape.LineFormat.FillFormat.FillType = FillType.Solid;
roundShape.LineFormat.FillFormat.SolidFillColor.Color = Color.Blue;

miterShape.LineFormat.JoinStyle = LineJoinStyle.Miter;
bevelShape.LineFormat.JoinStyle = LineJoinStyle.Bevel;
roundShape.LineFormat.JoinStyle = LineJoinStyle.Round;

miterShape.TextFrame.Text = "Miter Join Style";
bevelShape.TextFrame.Text = "Bevel Join Style";
roundShape.TextFrame.Text = "Round Join Style";

presentation.Save("join_styles.pptx", SaveFormat.Pptx);

Limit Miter Joins at Sharp Corners

Use ILineFormat.MiterLimit with ILineFormat.JoinStyle set to LineJoinStyle.Miter to limit how far a sharp corner can extend.

The limit is a ratio of the distance between the inner and outer corners of the join to the line width. For example, a value of 8 permits a miter length of up to eight times the line width; it is not a measurement in points. If the corner would exceed the limit, PowerPoint uses a beveled join at that corner. A larger limit allows sharper points. The setting affects miter joins only, and changing it has no visible effect when the corner remains within both limits.

This example creates two identical, unfilled triangles with outlines 20 points wide. The left triangle uses a limit of 2, and the right uses 8. Each triangle is 80 points wide and 160 points high, giving its top corner a miter-length-to-line-width ratio of approximately 4.12. Consequently, PowerPoint bevels the left apex and preserves the right apex.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
presentation.SlideSize.SetSize(500, 320, SlideSizeScaleType.DoNotScale);
var slide = presentation.Slides[0];

var miterLimits = new[] { 2f, 8f };

for (var i = 0; i < miterLimits.Length; i++)
{
    var triangle = slide.Shapes.AddAutoShape(ShapeType.Triangle, 90 + i * 240, 110, 80, 160);
    triangle.FillFormat.FillType = FillType.NoFill;
    triangle.LineFormat.Width = 20;
    triangle.LineFormat.FillFormat.FillType = FillType.Solid;
    triangle.LineFormat.FillFormat.SolidFillColor.Color = Color.DarkBlue;
    triangle.LineFormat.JoinStyle = LineJoinStyle.Miter;
    triangle.LineFormat.MiterLimit = miterLimits[i];
}

presentation.Save("miter_limits.pptx", SaveFormat.Pptx);

The result in PowerPoint: Miter limit 2 on the left and miter limit 8 on the right.

Gradient Fill

A gradient fill blends colors across a shape. This example fills an ellipse with a linear gradient at a 45-degree angle from red to purple using IFillFormat.GradientFormat. The IGradientStopCollection.Add method places the color stops at 0 and 1, the beginning and end of the gradient. Clearing the existing stops ensures that only these two colors are used.

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

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var shape = slide.Shapes.AddAutoShape(ShapeType.Ellipse, 50, 50, 150, 75);
shape.FillFormat.FillType = FillType.Gradient;
shape.FillFormat.GradientFormat.GradientShape = GradientShape.Linear;
shape.FillFormat.GradientFormat.LinearGradientAngle = 45;
shape.FillFormat.GradientFormat.GradientStops.Clear();
shape.FillFormat.GradientFormat.GradientStops.Add(1.0f, PresetColor.Purple);
shape.FillFormat.GradientFormat.GradientStops.Add(0.0f, PresetColor.Red);

presentation.Save("gradient_fill.pptx", SaveFormat.Pptx);

The result:

If a gradient looks different in an exported image than it does in PowerPoint, see Choose a Gradient Rendering Style. You can select a rendering style without changing the gradient fill stored in the presentation.

Set the Linear Gradient Angle

Use IGradientFormat.LinearGradientAngle to control the orientation of a GradientShape.Linear fill. The angle is measured in degrees and increases clockwise: 0 runs from left to right, 90 from top to bottom, 180 from right to left, and 270 from bottom to top. Fractional angles are supported. Finite angles outside [0, 360) are normalized to one revolution; for example, -45 becomes 315 and 360 becomes 0.

This example creates six rectangles with identical red, green, and blue stops at positions 0, 0.5, and 1. Scaling is disabled so that the angle can be compared independently of the rectangles' proportions. The angles, from left to right, are 0, 45, and 90 in the first row, and 135, 180, and 270 in the second row.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
presentation.SlideSize.SetSize(720, 400, SlideSizeScaleType.DoNotScale);
var slide = presentation.Slides[0];

var angles = new float[] { 0, 45, 90, 135, 180, 270 };

for (var i = 0; i < angles.Length; i++)
{
    var x = 30 + (i % 3) * 230;
    var y = 30 + (i / 3) * 190;

    var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, x, y, 200, 150);
    shape.LineFormat.FillFormat.FillType = FillType.NoFill;
    shape.FillFormat.FillType = FillType.Gradient;

    var gradient = shape.FillFormat.GradientFormat;
    gradient.GradientShape = GradientShape.Linear;
    gradient.GradientStops.Clear();
    gradient.GradientStops.Add(0f, Color.Red);
    gradient.GradientStops.Add(0.5f, Color.Lime);
    gradient.GradientStops.Add(1f, Color.Blue);
    gradient.LinearGradientScaled = NullableBool.False;
    gradient.LinearGradientAngle = angles[i];
}

presentation.Save("linear_gradient_angles.pptx", SaveFormat.Pptx);

The result in PowerPoint:

Scale a Linear Gradient with the Shape

IGradientFormat.LinearGradientScaled accepts a NullableBool value. Set it explicitly to False to keep the geometric gradient angle as the shape’s proportions change, or to True to scale the gradient with the shape’s width and height. With scaling enabled, the visible angle can differ from the assigned angle on a non-square shape.

The following example uses a 45-degree angle and the same color stops as the angle comparison. The left column uses False; the right column uses True. Each column contains a wide rectangle above a tall rectangle. Both start with the same wide dimensions; changing the second rectangle’s width and height demonstrates how the fill responds to resizing without changing its gradient settings.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
presentation.SlideSize.SetSize(720, 460, SlideSizeScaleType.DoNotScale);
var slide = presentation.Slides[0];

var scalingOptions = new[] { NullableBool.False, NullableBool.True };

for (var column = 0; column < scalingOptions.Length; column++)
{
    for (var row = 0; row < 2; row++)
    {
        var x = 30 + column * 360;
        var y = row == 0 ? 30 : 150;
        
        var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, x, y, 300, 90);
        shape.LineFormat.FillFormat.FillType = FillType.NoFill;
        shape.FillFormat.FillType = FillType.Gradient;

        var gradient = shape.FillFormat.GradientFormat;
        gradient.GradientShape = GradientShape.Linear;
        gradient.GradientStops.Clear();
        gradient.GradientStops.Add(0f, Color.Red);
        gradient.GradientStops.Add(0.5f, Color.Lime);
        gradient.GradientStops.Add(1f, Color.Blue);
        gradient.LinearGradientAngle = 45;
        gradient.LinearGradientScaled = scalingOptions[column];

        if (row == 1)
        {
            shape.Width = 90;
            shape.Height = 280;
        }
    }
}

presentation.Save("linear_gradient_scaling.pptx", SaveFormat.Pptx);

The result in PowerPoint, with scaling disabled on the left and enabled on the right:

With scaling disabled, the diagonal color bands keep the same orientation in both rectangles. With scaling enabled, the bands stretch with the shape’s proportions. This helps reproduce a template’s gradient when adapting a shape to a different size. On a square, enabling scaling does not change the appearance of this 45-degree gradient.

Both the angle and scaling settings apply to linear gradients. They do not control GradientShape.Radial or GradientShape.Rectangle fills.

Combine the Angle with Gradient Direction

IGradientFormat.GradientDirection selects a gradient style from the GradientDirection enumeration; it is not a substitute for a numeric angle. For a linear gradient, the corner styles can change the area over which the colors are distributed without changing LinearGradientAngle. Keep the direction unchanged when comparing angles or scaling.

The following example applies the same settings in opposite orders. The two rectangles have the same appearance: assigning the direction before or after the angle does not change the result.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];

for (var i = 0; i < 2; i++)
{
    var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 30, 30 + i * 140, 320, 100);
    shape.LineFormat.FillFormat.FillType = FillType.NoFill;
    shape.FillFormat.FillType = FillType.Gradient;

    var gradient = shape.FillFormat.GradientFormat;
    gradient.GradientShape = GradientShape.Linear;
    gradient.GradientStops.Clear();
    gradient.GradientStops.Add(0f, Color.Red);
    gradient.GradientStops.Add(0.5f, Color.Lime);
    gradient.GradientStops.Add(1f, Color.Blue);
    gradient.LinearGradientScaled = NullableBool.True;

    if (i == 0)
    {
        gradient.GradientDirection = GradientDirection.FromCorner1;
        gradient.LinearGradientAngle = 30;
    }
    else
    {
        gradient.LinearGradientAngle = 30;
        gradient.GradientDirection = GradientDirection.FromCorner1;
    }
}

presentation.Save("linear_gradient_direction.pptx", SaveFormat.Pptx);

Pattern Fill

A pattern fill applies a two-color design, such as dots, stripes, or checks. This example uses IPatternFormat.PatternStyle to select a trellis pattern. IPatternFormat.BackColor supplies the light gray background, and IPatternFormat.ForeColor supplies the yellow pattern color.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);
shape.FillFormat.FillType = FillType.Pattern;
shape.FillFormat.PatternFormat.PatternStyle = PatternStyle.Trellis;
shape.FillFormat.PatternFormat.BackColor.Color = Color.LightGray;
shape.FillFormat.PatternFormat.ForeColor.Color = Color.Yellow;

presentation.Save("pattern_fill.pptx", SaveFormat.Pptx);

The result:

Picture Fill

A picture fill uses an image inside a shape. This example requires a local image and uses Images.FromFile to load it into the presentation’s image collection. Setting IPictureFillFormat.PictureFillMode to the tiled mode repeats the image within the rectangle. The source image used here is shown below:

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

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 255, 130);
shape.FillFormat.FillType = FillType.Picture;
shape.FillFormat.PictureFillFormat.PictureFillMode = PictureFillMode.Tile;

using var image = Images.FromFile("lotus.png");
var presentationImage = presentation.Images.AddImage(image);
shape.FillFormat.PictureFillFormat.Picture.Image = presentationImage;

presentation.Save("picture_fill.pptx", SaveFormat.Pptx);

The result:

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.

This example requires a local image and configures IPictureFillFormat to repeat it at 50% of its original size. Offsets of −32 points shift the tiles horizontally and vertically; bottom-right alignment and flipping in both directions determine how the repeated texture is arranged.

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

using var presentation = new Presentation();
var firstSlide = presentation.Slides[0];

var shape = firstSlide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 190, 95);
shape.FillFormat.FillType = FillType.Picture;

using var sourceImage = Images.FromFile("lotus.png");
var presentationImage = presentation.Images.AddImage(sourceImage);

var pictureFillFormat = shape.FillFormat.PictureFillFormat;
pictureFillFormat.Picture.Image = presentationImage;
pictureFillFormat.PictureFillMode = PictureFillMode.Tile;
pictureFillFormat.TileOffsetX = -32;
pictureFillFormat.TileOffsetY = -32;
pictureFillFormat.TileScaleX = 50;
pictureFillFormat.TileScaleY = 50;
pictureFillFormat.TileAlignment = RectangleAlignment.BottomRight;
pictureFillFormat.TileFlip = TileFlip.FlipBoth;

presentation.Save("tile.pptx", SaveFormat.Pptx);

The result:

Solid Color Fill

A solid fill gives a shape a single, uniform color. This example sets IFillFormat.FillType to the solid fill mode and assigns yellow through IFillFormat.SolidFillColor, then saves the rectangle in a presentation.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);
shape.FillFormat.FillType = FillType.Solid;
shape.FillFormat.SolidFillColor.Color = Color.Yellow;

presentation.Save("solid_color_fill.pptx", SaveFormat.Pptx);

The result:

Copy Colors While Preserving Theme References

Use IColorFormat.CopyFrom to copy a color definition, including its color type, theme reference, and transformations. This is useful when transferring a fill color between shapes that should continue to follow the presentation theme. The method copies only the color: it does not copy the fill type, outline, or other shape formatting. Set the destination’s IFillFormat.FillType explicitly.

This example creates three rectangles, from left to right: the source, a theme-aware copy, and a fixed RGB copy. The source uses IColorFormat.SchemeColor to reference the first accent color and adds a tint through IColorOperationCollection.Add. The RGB copy uses the source’s effective fill color so all three initially look identical. Assigning IColorFormat.Color sets a fixed RGB value and clears any existing color transformations.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
presentation.SlideSize.SetSize(660, 220, SlideSizeScaleType.DoNotScale);
var slide = presentation.Slides[0];

presentation.MasterTheme.ColorScheme.Accent1.Color = Color.RoyalBlue;

var source = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 30, 40, 180, 140);
var themeCopy = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 240, 40, 180, 140);
var rgbCopy = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 450, 40, 180, 140);

foreach (var shape in new[] { source, themeCopy, rgbCopy })
{
    shape.FillFormat.FillType = FillType.Solid;
    shape.LineFormat.FillFormat.FillType = FillType.NoFill;
}

var sourceColor = source.FillFormat.SolidFillColor;
sourceColor.SchemeColor = SchemeColor.Accent1;
sourceColor.ColorTransform.Add(ColorTransformOperation.Tint, 0.75f);

themeCopy.FillFormat.SolidFillColor.CopyFrom(sourceColor);
rgbCopy.FillFormat.SolidFillColor.Color = source.FillFormat.GetEffective().SolidFillColor;

using var before = slide.GetImage(1f, 1f);
before.Save("color-copy-before.png", ImageFormat.Png);

// Theme references follow the new accent color; the fixed RGB value does not.
presentation.MasterTheme.ColorScheme.Accent1.Color = Color.OrangeRed;

using var after = slide.GetImage(1f, 1f);
after.Save("color-copy-after.png", ImageFormat.Png);
presentation.Save("copied_colors.pptx", SaveFormat.Pptx);

Before the theme change, all three fills match:

After the theme change, the source and the theme-aware copy follow the new accent color and retain their tint. The fixed RGB copy remains blue:

The copied definition is independent of the source. Subsequently changing the source’s theme reference, assigning another color, or adding or removing its transformations does not change the destination. A theme change still affects both shapes because each independently refers to the same theme color.

Saving and reopening the PPTX preserves the copied color’s IColorFormat.ColorType, theme reference, and IColorFormat.ColorTransform collection; it does not flatten the definition to RGB.

When copying between different theme contexts, such as presentations with different accent palettes, the copied reference resolves against the destination’s theme. The same reference and transformations can therefore produce a different visible color. See Presentation Theme for more about configuring theme colors.

Use the Slide Background as a Shape Fill

Use IAutoShape.UseBackgroundFill when a shape should match the slide background, for example in a presentation template. Set IFillFormat.FillType to FillType.NotDefined first to remove any explicit fill. With this combination, the shape uses the slide background instead of its style fill. Enabling the flag alone does not remove an existing explicit fill.

This differs from FillType.NoFill: background fill covers objects behind the shape with the corresponding area of the slide background, while no fill leaves those objects visible. A gradient remains aligned with the slide rather than restarting inside each shape.

The following example creates a master background inherited by the slide and places a magenta band behind three rectangles. The left rectangle uses the background, the middle rectangle has no fill, and the right rectangle switches from background fill to an explicit orange fill.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
presentation.SlideSize.SetSize(720, 400, SlideSizeScaleType.DoNotScale);
var slide = presentation.Slides[0];

// Inherit the gradient from the master.
slide.Background.Type = BackgroundType.NotDefined;
slide.LayoutSlide.Background.Type = BackgroundType.NotDefined;
var background = slide.LayoutSlide.MasterSlide.Background;
background.Type = BackgroundType.OwnBackground;
background.FillFormat.FillType = FillType.Gradient;
var gradient = background.FillFormat.GradientFormat;
gradient.GradientShape = GradientShape.Linear;
gradient.LinearGradientAngle = 0;
gradient.GradientStops.Clear();
gradient.GradientStops.Add(0, Color.DarkBlue);
gradient.GradientStops.Add(1, Color.LightSkyBlue);

// Add this object first so it appears behind the rectangles.
var band = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 25, 150, 670, 100);
band.FillFormat.FillType = FillType.Solid;
band.FillFormat.SolidFillColor.Color = Color.Magenta;
band.LineFormat.FillFormat.FillType = FillType.NoFill;

var backgroundShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 100, 160, 200);
backgroundShape.FillFormat.FillType = FillType.NotDefined;
backgroundShape.UseBackgroundFill = true;

var noFillShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 280, 100, 160, 200);
noFillShape.FillFormat.FillType = FillType.NoFill;

var explicitShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 510, 100, 160, 200);
explicitShape.FillFormat.FillType = FillType.NotDefined;
explicitShape.UseBackgroundFill = true;

// Disable background fill before applying an explicit fill.
explicitShape.UseBackgroundFill = false;
explicitShape.FillFormat.FillType = FillType.Solid;
explicitShape.FillFormat.SolidFillColor.Color = Color.Orange;

presentation.Save("background_fill.pptx", SaveFormat.Pptx);

The result, from left to right: background fill, no fill, and explicit fill. The magenta band is hidden by the left and right rectangles but remains visible through the middle rectangle.

The same behavior applies to a background defined directly on the slide or inherited from a layout. The shape uses the slide’s resolved background; the example leaves both the slide and layout backgrounds undefined so the master supplies it.

Set Transparency

For a solid fill, the color’s alpha component controls opacity: 0 is fully transparent and 255 is fully opaque. This example uses an alpha value of 128 for a yellow rectangle, making it approximately 50% transparent so the rectangle underneath remains visible. The color is assigned through IFillFormat.SolidFillColor.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

const int alpha = 128;

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var solidShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);

var transparentShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 80, 80, 150, 75);
transparentShape.FillFormat.FillType = FillType.Solid;
transparentShape.FillFormat.SolidFillColor.Color = Color.FromArgb(alpha, Color.Yellow);

presentation.Save("shape_transparency.pptx", SaveFormat.Pptx);

The result:

Rotate Shapes

Use IShape.Rotation to rotate a shape in the slide plane. The angle is measured in degrees; this example rotates a rectangle 5 degrees clockwise and saves the presentation.

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

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);
shape.Rotation = 5;

presentation.Save("shape_rotation.pptx", SaveFormat.Pptx);

The result:

Add 3D Bevel Effects

Use IShape.ThreeDFormat to give a shape depth and beveled edges. This example creates a green ellipse with an orange outline, sets IThreeDFormat.Depth to 4 points, and applies a circular top bevel with a width and height of 6 points through IThreeDFormat.BevelTop. A front-facing orthographic camera and three-point lighting make the bevel visible.

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var 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;
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;

presentation.Save("3D_bevel_effect.pptx", SaveFormat.Pptx);

The result:

Add 3D Rotation Effects

A shape’s 3D view is controlled by its camera settings. This example uses ICamera.SetRotation with latitude, longitude, and revolution angles of 40, 35, and 20 degrees, respectively. It selects an isometric camera through ICamera.CameraType and balanced lighting through ILightRig.LightType, then saves the formatted rectangle.

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

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var autoShape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 150, 75);
autoShape.TextFrame.Text = "Hello, Aspose!";
autoShape.ThreeDFormat.Camera.CameraType = CameraPresetType.IsometricLeftUp;
autoShape.ThreeDFormat.Camera.SetRotation(40, 35, 20);
autoShape.ThreeDFormat.LightRig.LightType = LightRigPresetType.Balanced;

presentation.Save("3D_rotation_effect.pptx", SaveFormat.Pptx);

The result:

Control Black-and-White Rendering for Shapes

The IShape.BlackWhiteMode property specifies how an individual shape is rendered when a presentation is viewed or processed in black-and-white mode. It does not enable black-and-white display by itself, and it does not change the shape’s fill, line, or other formatting in normal color mode.

Use a value from the BlackWhiteMode enumeration to select the desired behavior. For example, Automatic lets the rendering application choose the conversion, Gray and LightGray use gray coloring, BlackWhite uses only black and white, Black and White force a single color, Color preserves normal coloring, and Hidden omits the shape in black-and-white mode. NotDefined means that no shape-level mode is assigned.

This example creates an orange rectangle and sets IShape.BlackWhiteMode to gray. The saved shape retains its orange fill for normal color display and requests gray coloring from applications that honor black-and-white display settings:

using System.Drawing;
using Aspose.Slides;
using Aspose.Slides.Export;

using var presentation = new Presentation();
var slide = presentation.Slides[0];

var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, 50, 50, 200, 100);
shape.FillFormat.FillType = FillType.Solid;
shape.FillFormat.SolidFillColor.Color = Color.Orange;
shape.BlackWhiteMode = BlackWhiteMode.Gray;

presentation.Save("shape_black_white_mode.pptx", SaveFormat.Pptx);

In normal color mode, the rectangle retains its orange fill. In a black-and-white display workflow, it uses gray coloring because its mode is set to Gray. This lets you preserve a full-color slide while defining a distinct appearance for printing, previewing, or other workflows that honor the presentation’s black-and-white display settings.

Reset Formatting

Use ISlide.Reset to restore the position, size, and formatting of slide placeholders from their corresponding layout placeholders. This example requires an existing presentation with layout-linked placeholders and resets every slide before saving. Shapes without corresponding layout placeholders are not reset.

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

using var presentation = new Presentation("sample.pptx");
foreach (var slide in presentation.Slides)
{
    slide.Reset();
}

presentation.Save("reset_formatting.pptx", SaveFormat.Pptx);

FAQ

Does shape formatting affect the final presentation file size?

Colors, line styles, and effect settings generally add little data compared with embedded images and media. Picture fills can increase the file size because their images are stored in the presentation.

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 reapply their formatting wherever required.

Related features

• Set shape fills
• Format shape outlines

Related articles

• Manage Presentation Backgrounds in .NET