Manage Placeholder

Change Text in Placeholder

Using Aspose.Slides for .NET, you can find and modify placeholders on slides in presentations. Aspose.Slides allows you to make changes to the text in a placeholder.

Prerequisite: You need a presentation that contains a placeholder. You can create such a presentation in the standard Microsoft PowerPoint app.

This is how you use Aspose.Slides to replace the text in the placeholder in that presentation:

1. Instantiate the Presentation class and pass the presentation as an argument.
2. Get a slide reference through its index.
3. Iterate through the shapes to find the placeholder.
4. Typecast the placeholder shape to an AutoShape and change the text using the TextFrame associated with the AutoShape.
5. Save the modified presentation.

This C# code shows how to change the text in a placeholder:

// Instantiates a Presentation class
using (Presentation pres = new Presentation("ReplacingText.pptx"))
{

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

    // Iterates through shapes to find the placeholder
    foreach (IShape shp in sld.Shapes)
        if (shp.Placeholder != null)
        {
            // Changes the text in each placeholder
            ((IAutoShape)shp).TextFrame.Text = "This is a Placeholder";
        }

    // Saves the presentation to disk
    pres.Save("output_out.pptx", Aspose.Slides.Export.SaveFormat.Pptx);
}

Set Prompt Text in Placeholder

Standard and pre-built layouts contain placeholder prompt texts such as Click to add a title or Click to add a subtitle. Using Aspose.Slides, you can insert your preferred prompt texts into placeholder layouts.

This C# code shows you how to set the prompt text in a placeholder:

using (Presentation pres = new Presentation("Presentation2.pptx"))
{
    ISlide slide = pres.Slides[0];
    foreach (IShape shape in slide.Slide.Shapes) // Iterates through the slide
    {
        if (shape.Placeholder != null && shape is AutoShape)
        {
            string text = "";
            if (shape.Placeholder.Type == PlaceholderType.CenteredTitle) // PowerPoint displays "Click to add title"
            {
                text = "Add Title";
            }
            else if (shape.Placeholder.Type == PlaceholderType.Subtitle) // Adds subtitle
            {
                text = "Add Subtitle";
            }

            ((IAutoShape)shape).TextFrame.Text = text;

            Console.WriteLine($"Placeholder with text: {text}");
        }
    }

    pres.Save("Placeholders_PromptText.pptx", SaveFormat.Pptx);
}

Set Placeholder Image Transparency

Aspose.Slides allows you to set the transparency of the background image in a text placeholder. By adjusting the transparency of the picture in such a frame, you can make the text or the image stand out (depending on the text’s and picture’s colors).

This C# code shows you how to set the transparency for a picture background (inside a shape):

using (var presentation = new Presentation())
{
    IAutoShape autoShape = presentation.Slides[0].Shapes.AddAutoShape(ShapeType.Rectangle, 10, 10, 100, 100);
    
    autoShape.FillFormat.FillType = FillType.Picture;
    autoShape.FillFormat.PictureFillFormat.Picture.Image = presentation.Images.AddImage(File.ReadAllBytes("image.png"));
    autoShape.FillFormat.PictureFillFormat.PictureFillMode = PictureFillMode.Stretch;
    autoShape.FillFormat.PictureFillFormat.Picture.ImageTransform.AddAlphaModulateFixedEffect(75);
}