# Extract Chart Data

> Read editable chart categories, series and numeric values, export embedded workbooks, and identify external workbook references.

Source: https://docs.aspose.com/slides/net/examples/content-extraction/chart-data/
Updated: 2026-10-31



Read editable chart categories, series and numeric values, export embedded workbooks, and identify external workbook references.

## Run the example

Download the [complete project](example.zip), extract it, and run it with the .NET 8 SDK.
The project pins Aspose.Slides.NET6.CrossPlatform 26.10.0. The complete project uses portable image fixtures and the CrossPlatform package.
For the complete data assertions, set `ASPOSE_LICENSE_PATH` to your own valid license;
the visible helper loads it when supplied. Evaluation mode may truncate text or add watermarks.

```text
dotnet restore Example.csproj 
dotnet run --project Example.csproj --configuration Release --no-restore
```

The download contains [Program.cs](Program.cs), [Example.cs](Example.cs), the project,
dependency lock, and any JSON/CSV input. The helper source contains fixture generation,
license loading, serialization and assertions; it is part of the runnable project.
All presentation inputs are generated from original synthetic data. Results go to `output/`.

## Example

```csharp
using System.Threading.Tasks;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Globalization;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Text;
using System.Text.Json;
using Aspose.Slides;
using Aspose.Slides.Charts;
using Aspose.Slides.DOM.Ole;
using Aspose.Slides.Export;

internal static class Program
{
    private static ExampleContext Context = null!;
    private static Task<int> Main(string[] args) => ExampleBootstrap.RunAsync(args, async ctx =>
    {
        Context = ctx;
        Example.Context = ctx;
        ctx.BeginAction("content-extraction/chart-data/block-001");
        RunExample();
        string path=File.Exists("output/result.json")?"output/result.json":"result.json";
        using var result=JsonDocument.Parse(File.ReadAllText(path));
        var checks=new System.Collections.Generic.Dictionary<string,bool>();
        if(ctx.IsLicensed)
        {
            using var expected=JsonDocument.Parse("{\"checks.charts\":2,\"checks.embedded_workbooks\":1,\"checks.external_links\":1,\"checks.all_numeric_values_checked\":true,\"checks.external_data_not_refreshed\":true}");
            foreach(var field in expected.RootElement.EnumerateObject())
            {
                var actual=result.RootElement;foreach(string part in field.Name.Split('.'))actual=actual.GetProperty(part);
                ctx.Require(actual.ToString()==field.Value.ToString(),"Licensed assertion differs: "+field.Name);
                checks["licensed-"+field.Name.Replace('.','-')]=true;
            }
        }
        else
        {
            var values=result.RootElement.TryGetProperty("checks",out var nested)?nested:result.RootElement;
            foreach(var field in values.EnumerateObject())if(field.Value.ValueKind==JsonValueKind.False)throw new InvalidOperationException("Evaluation assertion failed: "+field.Name);
            checks["evaluation-semantic-effect"]=true;checks["evaluation-valid-output"]=true;
        }
        foreach(string pdf in Directory.GetFiles(".","*.pdf",SearchOption.AllDirectories))ctx.Require(File.ReadAllBytes(pdf).AsSpan(0,5).SequenceEqual(System.Text.Encoding.ASCII.GetBytes("%PDF-")),"Invalid PDF output.");
        foreach(string png in Directory.GetFiles(".","*.png",SearchOption.AllDirectories)){var image=PortableImage.Decode(File.ReadAllBytes(png));ctx.Require(image.Width>0&&image.Height>0,"Empty PNG output.");}
        ctx.Pass("content-extraction/chart-data/block-001",checks);
        await Task.CompletedTask;
    });


    private sealed record SeriesData(string Name,double?[] Values);
    private sealed record ChartData(int Slide,string Shape,string Source,string? ExternalWorkbook,string[] Categories,SeriesData[] Series);
    private static void RunExample()
    {
        Example.Setup();using(var p=new Presentation())
        {var chart=Example.Chart(p.Slides[0],"Internal chart");Example.ChartData(chart,new[]{"Jan","Feb"},new[]{"North","South"},new[]{new[]{125.5,80.0},new[]{50.0,75.25}});
         var external=p.Slides.AddEmptySlide(p.LayoutSlides[0]);var linked=Example.Chart(external,"External chart");Example.ChartData(linked,new[]{"Cached"},new[]{"Cached"},new[]{new[]{10.0}});linked.ChartData.SetExternalWorkbook("https://example.invalid/unfetched.xlsx",false);p.Save("output/input.pptx",SaveFormat.Pptx);}
        using var input=new Presentation("output/input.pptx");var rows=new List<ChartData>();int workbooks=0;
        for(int i=0;i<input.Slides.Count;i++)foreach(var chart in Example.Walk(input.Slides[i].Shapes).OfType<IChart>())
        {var data=chart.ChartData;bool external=data.DataSourceType==ChartDataSourceType.ExternalWorkbook;
         // Do not read linked category/series cells: doing so can open the external workbook.
         var categories=external?Array.Empty<string>():data.Categories.Select(c=>c.Value?.ToString()??"").ToArray();
         var series=external?Array.Empty<SeriesData>():data.Series.Select(s=>new SeriesData(s.Name.ToString(),s.DataPoints.Select(point=>point.Value.Data==null?(double?)null:Convert.ToDouble(point.Value.Data,CultureInfo.InvariantCulture)).ToArray())).ToArray();
         rows.Add(new(i+1,chart.Name,external?"external_not_read":"embedded",external?data.ExternalWorkbookPath:null,categories,series));
         if(!external){using var stream=data.ReadWorkbookStream();using var file=File.Create("output/workbook-"+(i+1)+".xlsx");stream.CopyTo(file);workbooks++;}}
        Example.Json("output/chart-data.json",rows);
        var first=rows[0];Example.Require(first.Categories.SequenceEqual(new[]{"Jan","Feb"}),"Categories differ.");
        Example.Require(first.Series[0].Name=="North"&&first.Series[1].Name=="South","Series names differ.");
        Example.Require(first.Series[0].Values.SequenceEqual(new double?[]{125.5,80})&&first.Series[1].Values.SequenceEqual(new double?[]{50,75.25}),"Numeric data differs.");
        Example.Require(rows[1].ExternalWorkbook=="https://example.invalid/unfetched.xlsx"&&workbooks==1,"External workbook policy differs.");
        using(var zip=ZipFile.OpenRead("output/workbook-1.xlsx"))Example.Require(zip.GetEntry("xl/workbook.xml")!=null,"Missing workbook package.");
        Example.Result(new{charts=2,embedded_workbooks=1,external_links=1,all_numeric_values_checked=true,external_data_not_refreshed=true});
    }

}
```

## Expected result and checks

The program writes its semantic checks to `output/result.json` and throws if a required
result differs. Expected check values are:

```json
{
  "charts": 2,
  "embedded_workbooks": 1,
  "external_links": 1,
  "all_numeric_values_checked": true,
  "external_data_not_refreshed": true
}
```

Embedded values are preserved as numbers or null. For external workbooks the JSON records the link and the explicit external_not_read state, with empty category/series arrays. Reading linked workbook cells can cause a download, so this offline example does not inspect them. Missing values remain null; the example does not invent external data or turn chart images into editable data.

## Learn more

- [Manage Chart Workbooks in Presentations in .NET](https://docs.aspose.com/slides/net/chart-workbook/)
- [Manage Chart Data Series in Presentations in .NET](https://docs.aspose.com/slides/net/chart-series/)


## Open and run the complete project

[Download the complete project](example.zip), extract it and open `Example.sln`, or run:

```text
dotnet restore Example.sln
dotnet run --project Example.csproj --configuration Release -- --mode evaluation
```

Use the current supported .NET 10 SDK/runtime. The project keeps a stable `net8.0`
target and accepts compatible stable SDKs; no exact SDK patch is required.
Evaluation runs without a license and explicitly ignores license environment settings.
It uses bounded fixtures and checks valid output while allowing the evaluation watermark
and documented read-back text truncation. For unrestricted checks, use `--mode licensed`
with your authorized `ASPOSE_LICENSE_PATH`. No license is included.

Inputs are copied from `Fixtures` into a separate output workspace. The program prints
the absolute output path; `execution.json` records the actual runtime and verified action.
The portable PNG helper creates original synthetic pixels without a Windows bitmap engine.
See [setup and prerequisites](/slides/net/examples/getting-started/) for native libraries,
fonts, IDE settings and the .NET 8/9 runtime support boundary of 2026-11-10.