Optimizing the order of slides in a PowerPoint presentation is a simple skill. By rearranging slides, you can refine the logic and flow of your presentation, group related points together, or move slides to more impactful locations. This flexibility enables you to create a cohesive, engaging narrative that captivates your audience.

This article demonstrates how to programmatically change the slide order in a PowerPoint document in C# by using the Spire.Presentation for .NET library.

Install Spire.Presentation for .NET

To begin with, you need to add the DLL files included in the Spire.Presentation for .NET package as references in your .NET project. The DLL files can be either downloaded from this link or installed via NuGet.

PM> Install-Package Spire.Presentation

Change the Slide Order in a PowerPoint Document in C#

To reorder slides in a PowerPoint presentation, create two Presentation objects - one to load the original document and another to create a new document. By copying the slides from the original document to the new one in the desired sequence, you can easily rearrange the slide order.

The steps to rearrange slides in a PowerPoint document using C# are as follows.

• Create a Presentation object.
• Load a PowerPoint document using Presentation.LoadFromFile() method.
• Specify the slide order within an array.
• Create another Presentation object for creating a new presentation.
• Add the slides from the original document to the new presentation in the specified order using Presentation.Slides.Append() method.
• Save the new presentation to a PPTX file using Presentation.SaveToFile() method.

using Spire.Presentation;

namespace ChangeSlideOrder
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a Presentation object
            Presentation presentation = new Presentation();

            // Load a PowerPoint file
            presentation.LoadFromFile("C:\\Users\\Administrator\\Desktop\\input.pptx");

            // Specify the new slide order within an array
            int[] newSlideOrder = new int[] { 4, 2, 1, 3 };

            // Create another Presentation object
            Presentation new_presentation = new Presentation();

            // Remove the default slide
            new_presentation.Slides.RemoveAt(0);

            // Iterate through the array
            for (int i = 0; i < newSlideOrder.Length; i++)
            {
                // Add the slides from the original PowerPoint file to the new PowerPoint document in the new order
                new_presentation.Slides.Append(presentation.Slides[newSlideOrder[i] - 1]);
            }

            // Save the new presentation to file
            new_presentation.SaveToFile("NewOrder.pptx", FileFormat.Pptx2019);

            // Dispose resources
            presentation.Dispose();
            new_presentation.Dispose();
        }
    }
}

Apply for a Temporary License

If you'd like to remove the evaluation message from the generated documents, or to get rid of the function limitations, please request a 30-day trial license for yourself.

Spire.Presentation is a powerful and easy-to-use .NET component, especially designed for developers. Using Spire.Presentation you can generate, modify, convert, render, and print documents without installing Microsoft PowerPoint on your machine. In this document, I will introduce you how to create PowerPoint file and save it to stream. I also introduce you how to load PowerPoint file from stream. Check it below.

Create PowerPoint file and save it to Stream

Step 1: Create Presentation instance.

Presentation presentation = new Presentation();

Step 2: Set background image.

string ImageFile = "bg.png";
RectangleF rect = new RectangleF(0, 0, presentation.SlideSize.Size.Width, presentation.SlideSize.Size.Height);
presentation.Slides[0].Shapes.AppendEmbedImage(ShapeType.Rectangle, ImageFile, rect);
presentation.Slides[0].Shapes[0].Line.FillFormat.SolidFillColor.Color = Color.FloralWhite;

Step 3: Add text to PowerPoint document.

IAutoShape shape = presentation.Slides[0].Shapes.AppendShape(ShapeType.Rectangle, new RectangleF(50, 70, 450, 150));
shape.Fill.FillType = FillFormatType.None;
shape.ShapeStyle.LineColor.Color = Color.White;

//add text to shape
shape.TextFrame.Text = "This demo shows how to Create PowerPoint file and save it to Stream.";
shape.TextFrame.Paragraphs[0].TextRanges[0].Fill.FillType = FillFormatType.Solid;
shape.TextFrame.Paragraphs[0].TextRanges[0].Fill.SolidColor.Color = Color.Black;

Step 4: Save document to stream.

FileStream to_stream = new FileStream("To_stream.pptx", FileMode.Create);
presentation.SaveToFile(to_stream, FileFormat.Pptx2010);
to_stream.Close();

Preview the generated PowerPoint file:

Load PowerPoint file from stream.

Step 1: Create Presentation instance.

Presentation presentationLoad = new Presentation();

Step 2: Load PowerPoint file from stream.

FileStream from_stream = File.OpenRead("sample.pptx");
presentationLoad.LoadFromStream(from_stream, FileFormat.Pptx2010);

Step 3: Save the document.

presentationLoad.SaveToFile("From_stream.pptx",FileFormat.Pptx2010);
from_stream.Dispose();

Preview the PowerPoint file:

Full code:

using Spire.Presentation;
using Spire.Presentation.Drawing;
using System.Drawing;
using System.IO;
namespace SavePPTtoStream
{
    class Program
    {
        static void Main(string[] args)
        {

            //A: create PowerPoint file and save it to stream
            Presentation presentation = new Presentation();

            //set background Image
            string ImageFile = "bg.png";
            RectangleF rect = new RectangleF(0, 0, presentation.SlideSize.Size.Width, presentation.SlideSize.Size.Height);
            presentation.Slides[0].Shapes.AppendEmbedImage(ShapeType.Rectangle, ImageFile, rect);
            presentation.Slides[0].Shapes[0].Line.FillFormat.SolidFillColor.Color = Color.FloralWhite;

            //append new shape
            IAutoShape shape = presentation.Slides[0].Shapes.AppendShape(ShapeType.Rectangle, new RectangleF(50, 70, 450, 150));
            shape.Fill.FillType = FillFormatType.None;
            shape.ShapeStyle.LineColor.Color = Color.White;

            //add text to shape
            shape.TextFrame.Text = "This demo shows how to Create PowerPoint file and save it to Stream.";
            shape.TextFrame.Paragraphs[0].TextRanges[0].Fill.FillType = FillFormatType.Solid;
            shape.TextFrame.Paragraphs[0].TextRanges[0].Fill.SolidColor.Color = Color.Black;

            //save to Stream
            FileStream to_stream = new FileStream("To_stream.pptx", FileMode.Create);
            presentation.SaveToFile(to_stream, FileFormat.Pptx2010);
            to_stream.Close();

            System.Diagnostics.Process.Start("To_stream.pptx");


            //B: Load PowerPoint file from Stream
            Presentation presentationLoad = new Presentation();

            //load PowerPoint file from stream
            FileStream from_stream = File.OpenRead("sample.pptx");
            presentationLoad.LoadFromStream(from_stream, FileFormat.Pptx2010);

            //save the document
            presentationLoad.SaveToFile("From_stream.pptx", FileFormat.Pptx2010);
            from_stream.Dispose();

            System.Diagnostics.Process.Start("From_stream.pptx");


        }
    }
}

If you couldn't successfully use Spire.Presentation, please refer Spire.Presentation Quick Start which can guide you quickly use Spire.Presentation.

Sometimes, we may need to delete specific slide in a PowerPoint presentation due to any reason. This section will illustrate that how we can accomplish that task using Spire.Presentation for .NET.

As a matter of fact, it is quite easy and convenient to remove slides by only one line of core code if you have Spire.Presentation.Dll installed as a reference in your .NET project assemblies. Here is the method:

Step 1: Create an instance of presentation class and load PPT documents

Presentation presentation = new Presentation();
presentation.LoadFromFile("sample.pptx");

Step 2: Remove the second slide from the presentation by using its index position

presentation.Slides.RemoveAt(1);

Step 3: Save and review

presentation.SaveToFile("result.pptx",FileFormat.Pptx2010);
System.Diagnostics.Process.Start("result.pptx");

Original layout:

Result:

Full C# code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Spire.Presentation;

namespace RemoveSlide
{
    class Program
    {
        static void Main(string[] args)
        {
            Presentation presentation = new Presentation();
            presentation.LoadFromFile("sample.pptx");

            //remove the second slide
            presentation.Slides.RemoveAt(1);

             presentation.SaveToFile("result.pptx",FileFormat.Pptx2010);
            System.Diagnostics.Process.Start("result.pptx");
        }
    }
}

Changing slide size is one way to maintain the visual integrity of your PowerPoint presentation. By adjusting the slide size to the specific aspect ratio and dimensions of the target screen or projection device, you can avoid issues such as content appearing cropped, stretched, or distorted. In this article, you will learn how to change the slide size of a PowerPoint presentation in C# using Spire.Presentation for .NET.

• Change the Slide Size to a Preset Size
• Change the Slide Size to a Custom Size

Install Spire.Presentation for .NET

To begin with, you need to add the DLL files included in the Spire.Presentation for.NET package as references in your .NET project. The DLL files can be either downloaded from this link or installed via NuGet.

PM> Install-Package Spire.Presentation

Change the Slide Size to a Preset Size in C#

Spire.Presentation for .NET provides the Presentation.SlideSize.Type property to set or change the slide size to a preset size. The following are the detailed steps.

• Create a Presentation instance.
• Load a PowerPoint presentation using Presentation.LoadFromFile() method.
• Change the slide type of the presentation using Presentation.SlideSize.Type property.
• Save the result document using Presentation.SaveToFile() method.

using Spire.Presentation;

namespace CreateCombination
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a Presentation instance
            Presentation ppt = new Presentation();

            //Load a presentation file
            ppt.LoadFromFile("sample.pptx");

            //Change the slide size of the presentation
            ppt.SlideSize.Type = SlideSizeType.Screen4x3;

            //Save the result file
            ppt.SaveToFile("SlideSize.pptx", FileFormat.Pptx2013);
            ppt.Dispose();
        }
    }
}

Change the Slide Size to a Custom Size in C#

Customizing the size of slides requires changing the slide size type to Custom first, and then you can set a desired size through the Presentation.SlideSize.Size property. The following are the detailed steps.

• Create a Presentation instance.
• Load a PowerPoint presentation using Presentation.LoadFromFile() method.
• Change the slide size type to custom using Presentation.SlideSize.Type property.
• Customize the slide size using Presentation.SlideSize.Size property.
• Save the result document using Presentation.SaveToFile() method.

using Spire.Presentation;
using System.Drawing;

namespace CreateCombination
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a Presentation instance
            Presentation ppt = new Presentation();

            //Load a presentation file
            ppt.LoadFromFile("sample.pptx");

            //Change the slide size type to custom
            ppt.SlideSize.Type = SlideSizeType.Custom;

            //Set the slide size
            ppt.SlideSize.Size = new SizeF(900, 600);

            //Save the presentation file
            ppt.SaveToFile("CustomSize.pptx", FileFormat.Pptx2013);
            ppt.Dispose();
        }
    }
}