Add Line Shapes to Presentations in .NET

Overview

Aspose.Slides allows you to add line shapes to PowerPoint slides programmatically. This article shows how to create a simple line and how to customize a line so it appears as an arrow.

You will learn how to add a line shape to a slide, adjust its visual appearance, and save the updated presentation. The examples focus on practical line formatting settings such as style, width, dash pattern, arrowhead options, and fill color.

Create a Plain Line

To add a simple plain line to a selected slide of the presentation, please follow the steps below:

• Create an instance of Presentation class.
• Obtain the reference of a slide by using its Index.
• Add an AutoShape of Line type using AddAutoShape method exposed by Shapes object.
• Write the modified presentation as a PPTX file.

In the example given below, we have added a line to the first slide of the presentation.

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

    // Add an autoshape of type line
    sld.Shapes.AddAutoShape(ShapeType.Line, 50, 150, 300, 0);

    //Write the PPTX to Disk
    pres.Save("LineShape1_out.pptx", SaveFormat.Pptx);
}

Create an Arrow-Shaped Line

Aspose.Slides for .NET also allows developers to configure some properties of the line to make it look more appealing. Let’s try to configure few properties of a line to make it look like an arrow. Please follow the steps below to do so:

• Create an instance of Presentation class.
• Obtain the reference of a slide by using its Index.
• Add an AutoShape of Line type using AddAutoShape method exposed by Shapes object.
• Set the Line Style to one of the styles as offered by Aspose.Slides for .NET.
• Set the Width of the line.
• Set the Dash Style of the line to one of the styles offered by Aspose.Slides for .NET.
• Set the Arrow Head Style and Length of the start point of the line.
• Set the Arrow Head Style and Length of the end point of the line.
• Write the modified presentation as a PPTX file.

// Instantiate PresentationEx class that represents the PPTX file
using (Presentation pres = new Presentation())
{

    // Get the first slide
    ISlide sld = pres.Slides[0];

    // Add an autoshape of type line
    IAutoShape shp = sld.Shapes.AddAutoShape(ShapeType.Line, 50, 150, 300, 0);

    // Apply some formatting on the line
    shp.LineFormat.Style = LineStyle.ThickBetweenThin;
    shp.LineFormat.Width = 10;

    shp.LineFormat.DashStyle = LineDashStyle.DashDot;

    shp.LineFormat.BeginArrowheadLength = LineArrowheadLength.Short;
    shp.LineFormat.BeginArrowheadStyle = LineArrowheadStyle.Oval;

    shp.LineFormat.EndArrowheadLength = LineArrowheadLength.Long;
    shp.LineFormat.EndArrowheadStyle = LineArrowheadStyle.Triangle;

    shp.LineFormat.FillFormat.FillType = FillType.Solid;
    shp.LineFormat.FillFormat.SolidFillColor.Color = Color.Maroon;

    //Write the PPTX to Disk
    pres.Save("LineShape2_out.pptx", SaveFormat.Pptx);
}

FAQ

Can I convert a regular line into a connector so it “snaps” to shapes?

No. A regular line (an AutoShape of type Line) does not automatically become a connector. To make it snap to shapes, use the dedicated Connector type and the corresponding APIs for connections.

What should I do if a line’s properties are inherited from the theme and it’s hard to determine the final values?

Read the effective properties through the ILineFormatEffectiveData/ILineFillFormatEffectiveData interfaces—these already account for inheritance and theme styles.

Can I lock a line against editing (moving, resizing)?

Yes. Shapes provide lock objects that let you disallow editing operations.