How to Read and Modify Text by Slide Index in a Presentation in C#?

Aspose.Slides Product Family
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1

Hi,

I have found the following code in documentation which reads text from the complete PPT file (all slides). However, I want to read each piece of text from a specific slide using index, i.e. Slides[0], and modify that text (set text) programmatically. Would you please guide me how to do that? Thanks.

C# .NET:

//Instatiate Presentation class that represents a PPTX file
Presentation pptxPresentation = new Presentation("demo.pptx");

//Get an Array of ITextFrame objects from all slides in the PPTX
ITextFrame[] textFramesPPTX = Aspose.Slides.Util.SlideUtil.GetAllTextFrames(pptxPresentation, true); 

//Loop through the Array of TextFrames
for (int i = 0; i < textFramesPPTX.Length; i++)
{
    //Loop through paragraphs in current ITextFrame
    foreach (IParagraph para in textFramesPPTX[i].Paragraphs)
    {
        //Loop through portions in the current IParagraph
        foreach (IPortion port in para.Portions)
        {
            //Display text in the current portion
            Console.WriteLine(port.Text); 
        }
    }
}
2

@uax99

To read and modify text from a specific slide in a PowerPoint presentation using Aspose.Slides, you can follow these steps. Below is a C# example that demonstrates how to access a specific slide by its index, read the text, and modify it.

C# Example

// Instantiate Presentation class that represents a PPTX file
Presentation pptxPresentation = new Presentation("demo.pptx");

// Access the specific slide by index (e.g., first slide)
ISlide slide = pptxPresentation.Slides[0];

// Iterate through shapes in the slide
foreach (IShape shape in slide.Shapes)
{
    // Check if the shape has a text frame
    if (shape is IAutoShape autoShape && autoShape.TextFrame != null)
    {
        // Display the current text
        Console.WriteLine(autoShape.TextFrame.Text);

        // Modify the text
        autoShape.TextFrame.Text = "This is the modified text.";
    }
}

// Save the modified presentation
pptxPresentation.Save("modified_demo.pptx", SaveFormat.Pptx);

Explanation

  1. Instantiate the Presentation: Load your PPTX file using the Presentation class.
  2. Access the Slide: Use the slide index to access a specific slide. In this case, Slides[0] accesses the first slide.
  3. Iterate Through Shapes: Loop through all shapes in the slide to find those that contain text.
  4. Modify Text: If a shape has a text frame, you can read its current text and modify it as needed.
  5. Save Changes: Finally, save the modified presentation to a new file.

This approach allows you to programmatically read and modify text on a specific slide in your PowerPoint presentation.

If you have any further questions or need additional assistance, feel free to ask!

3

Thank you.

What is the difference between Shapes and TextBoxes and TextFrames? Can we access each piece of text on a slide using Shape collection? Or we need to iterate through TextFrames and TextBoxes also?

4

@uax99,
The SlideUtil.GetAllTextFrames method you found finds all PowerPoint shapes that contain text frames. The IShape interface is the base interface for many shapes. Not every shape can contain a text frame. For example, IAutoShape, inherited from IShape, can contain a text frame, but IChart cannot. Text boxes in PowerPoint documents are autoshapes.

You can access each piece of text on a slide using the IShape collection as shown above.

5

Thanks @andrey.potapov ,

What about the following code? Will this work for all text pieces?

//Instatiate Presentation class that represents a PPTX file
Presentation pptxPresentation = new Presentation("demo.ppt");

foreach (var slide in pptxPresentation.Slides)
{
    ITextFrame[] TextFrames = SlideUtil.GetAllTextBoxes(slide);

    for (int i = 0; i < TextFrames.Length; i++)
    {
        //Loop through paragraphs in current ITextFrame
        foreach (IParagraph para in TextFrames[i].Paragraphs)
        {
            //Loop through portions in the current IParagraph
            foreach (IPortion port in para.Portions)
            {
                //Display text in the current portion
                string text = port.Text;
                port.Text = "[Updated]" + text;
            }
        }
    }
}
6

@uax99,
Yes, the SlideUtil.GetAllTextBoxes method allows you to get all text frames from a slide.

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