Build a Presentation Preview Gallery

What this page is about

Complete runnable C# project to build a presentation preview gallery using Aspose.Slides for .NET.

Create a preview gallery and JSON index for a presentation. The example uses duplicate titles and a non-ASCII input filename, generates filenames from slide numbers and escapes titles in HTML. Open gallery.html with its three thumbnail files beside it.

Inputs and execution

Download the complete project, including its original inputs, all source and pinned dependencies. The projects were tested on Windows x64 with Arial and the .NET SDK8.0.427 pinned in global.json. Set ASPOSE_LICENSE_PATH to your license file; unrestricted content checks require a valid license. See licensing. No PowerPoint installation is required.

dotnet run --project Example.csproj --configuration Release

The program generates its own original presentation/template fixture. JSON inputs, when present, are included in the download. All output files are separate from those inputs.

Complete project source

using System;
using System.IO;
using System.Linq;
using System.Net;
using System.Drawing;
using System.Security.Cryptography;
using System.Text.Json;
using Aspose.Slides;
using Aspose.Slides.Charts;
using Aspose.Slides.Export;
using Aspose.Slides.Vba;

internal static class Program
{
    private static void Main()
    {
        var path = Environment.GetEnvironmentVariable("ASPOSE_LICENSE_PATH");
        if (!string.IsNullOrWhiteSpace(path)) new License().SetLicense(path);
        using (var input = Deck("<Planning & Review>", "<Planning & Review>", "Результаты")) input.Save("презентация.pptx", SaveFormat.Pptx);
        using var source = new Presentation("презентация.pptx");
        var items = new System.Collections.Generic.List<object>();
        var html = new System.Text.StringBuilder("""<!doctype html><html lang="en"><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"><title>Presentation gallery</title><body><h1>Presentation gallery</h1>""");
        for (int i = 0; i < source.Slides.Count; i++)
        {
            string file = $"slide-{i + 1}.png"; string title = Text(source.Slides[i]);
            using var image = source.Slides[i].GetImage(new Size(320, 180)); image.Save(file, Aspose.Slides.ImageFormat.Png);
            items.Add(new { slide = i + 1, title, thumbnail = file });
            html.Append($"""<figure><img width="320" height="180" src="{file}" alt="Slide {i + 1}"><figcaption>{i + 1}. {WebUtility.HtmlEncode(title)}</figcaption></figure>""");
        }
        html.Append("</body></html>"); File.WriteAllText("gallery.html", html.ToString());
        File.WriteAllText("gallery.json", JsonSerializer.Serialize(items, new JsonSerializerOptions { WriteIndented = true }));
        Require(html.ToString().Contains("&lt;Planning &amp; Review&gt;"), "HTML labels must be escaped.");
        Report(new { slides = items.Count, unique_filenames = true, escaped_labels = true });
    }

    private static Presentation Deck(params string[] titles)
    {
        var deck = new Presentation();
        deck.SlideSize.SetSize(960, 540, SlideSizeScaleType.DoNotScale);
        var layout = deck.LayoutSlides.GetByType(SlideLayoutType.Blank);
        for (int i = 0; i < titles.Length; i++)
        {
            var slide = i == 0 ? deck.Slides[0] : deck.Slides.AddEmptySlide(layout);
            Label(slide, titles[i], "Title", 40, 30, 880, 80);
        }
        return deck;
    }

    private static IAutoShape Label(ISlide slide, string value, string name, float x, float y, float w, float h)
    {
        var shape = slide.Shapes.AddAutoShape(ShapeType.Rectangle, x, y, w, h);
        shape.Name = name;
        shape.FillFormat.FillType = FillType.Solid;
        shape.FillFormat.SolidFillColor.Color = Color.AliceBlue;
        shape.LineFormat.FillFormat.FillType = FillType.NoFill;
        shape.TextFrame.Text = value;
        shape.TextFrame.TextFrameFormat.AutofitType = TextAutofitType.Normal;
        foreach (var paragraph in shape.TextFrame.Paragraphs)
        foreach (var portion in paragraph.Portions)
        {
            portion.PortionFormat.FontHeight = 24;
            portion.PortionFormat.LatinFont = new FontData("Arial");
            portion.PortionFormat.FillFormat.FillType = FillType.Solid;
            portion.PortionFormat.FillFormat.SolidFillColor.Color = Color.Black;
        }
        return shape;
    }

    private static string Text(ISlide slide) => string.Join(" ", slide.Shapes.OfType<IAutoShape>().Select(s => s.TextFrame?.Text));
    private static string Hash(string path) => Convert.ToHexString(SHA256.HashData(File.ReadAllBytes(path)));
    private static void Require(bool value, string message) { if (!value) throw new InvalidOperationException(message); }
    private static void Preview(Presentation deck, string path)
    {
        using var image = deck.Slides[0].GetImage(new Size(640, 360));
        image.Save(path, Aspose.Slides.ImageFormat.Png);
    }
    private static void Report(object value)
    {
        string json = JsonSerializer.Serialize(value, new JsonSerializerOptions { WriteIndented = true });
        File.WriteAllText("result.json", json); Console.WriteLine(json);
    }
}

Expected outputs

The project writes gallery.html, gallery.json, slide-1.png, slide-2.png, slide-3.png and result.json. Reopen the PPTX/PDF or gallery and inspect its content before adapting the code to a real dataset. Production applications should validate external inputs and choose their own output paths and credentials.

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