Word Charts in C# and VB.NET

Chart elements are drawings used for graphical data representation. GemBox.Document provides support for working with charts programmatically with the help of the GemBox.Spreadsheet component.

With GemBox.Spreadsheet, GemBox.Document can create and update charts in Word documents. It can also export documents with graphs to PDF, XPS, or image formats.
Without GemBox.Spreadsheet, GemBox.Document is only able to preserve charts in Word documents.

Create chart

To enable GemBox.Document's support and work with Chart objects, you'll need to add a reference to GemBox.Spreadsheet library and call its SpreadsheetInfo.SetLicense method.

Note, if you don't have a GemBox.Spreadsheet license you can use its Free mode.

You can choose to create charts from the following types:

Area
Bar
Column
Combo
Line
Pie
Scatter

The following example shows how to create a document with a bar chart using C# and VB.NET.

PDF document with chart element — Screenshot of PDF document with chart

C#
VB.NET

View on GitHub

using GemBox.Document;
using GemBox.Spreadsheet;
using GemBox.Spreadsheet.Charts;

class Program
{
    static void Main()
    {
        // If using the Professional version, put your GemBox.Document serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY");

        // If using the Professional version, put your GemBox.Spreadsheet serial key below.
        SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY");

        var document = new DocumentModel();

        // Create Word chart and add it to document.
        var chart = new Chart(document, GemBox.Document.ChartType.Bar,
            new FloatingLayout(
                new HorizontalPosition(HorizontalPositionType.Center, HorizontalPositionAnchor.Margin),
                new VerticalPosition(VerticalPositionType.Top, VerticalPositionAnchor.Paragraph),
                new Size(14, 7, GemBox.Document.LengthUnit.Centimeter)));

        document.Sections.Add(
            new Section(document,
                new Paragraph(document, "New document with chart element."),
                new Paragraph(document, chart)));

        // Get underlying Excel chart.
        ExcelChart excelChart = (ExcelChart)chart.ExcelChart;
        ExcelWorksheet worksheet = excelChart.Worksheet;

        // Add data for Excel chart.
        worksheet.Cells["A1"].Value = "Name";
        worksheet.Cells["A2"].Value = "John Doe";
        worksheet.Cells["A3"].Value = "Fred Nurk";
        worksheet.Cells["A4"].Value = "Hans Meier";
        worksheet.Cells["A5"].Value = "Ivan Horvat";

        worksheet.Cells["B1"].Value = "Salary";
        worksheet.Cells["B2"].Value = 3600;
        worksheet.Cells["B3"].Value = 2580;
        worksheet.Cells["B4"].Value = 3200;
        worksheet.Cells["B5"].Value = 4100;

        // Select data.
        excelChart.SelectData(worksheet.Cells.GetSubrange("A1:B5"), true);

        document.Save("Created Chart.%OutputFileType%");
    }
}

Imports GemBox.Document
Imports GemBox.Spreadsheet
Imports GemBox.Spreadsheet.Charts

Module Program

    Sub Main()

        ' If using the Professional version, put your GemBox.Document serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY")

        ' If using the Professional version, put your GemBox.Spreadsheet serial key below.
        SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY")

        Dim document As New DocumentModel()

        ' Create Word chart and add it to document.
        Dim chart As New Chart(document, GemBox.Document.ChartType.Bar,
            New FloatingLayout(
                New HorizontalPosition(HorizontalPositionType.Center, HorizontalPositionAnchor.Margin),
                New VerticalPosition(VerticalPositionType.Top, VerticalPositionAnchor.Paragraph),
                New Size(14, 7, GemBox.Document.LengthUnit.Centimeter)))

        document.Sections.Add(
            New Section(document,
                New Paragraph(document, "New document with chart element."),
                New Paragraph(document, chart)))

        ' Get underlying Excel chart.
        Dim excelChart As ExcelChart = DirectCast(chart.ExcelChart, ExcelChart)
        Dim worksheet As ExcelWorksheet = excelChart.Worksheet

        ' Add data for Excel chart.
        worksheet.Cells("A1").Value = "Name"
        worksheet.Cells("A2").Value = "John Doe"
        worksheet.Cells("A3").Value = "Fred Nurk"
        worksheet.Cells("A4").Value = "Hans Meier"
        worksheet.Cells("A5").Value = "Ivan Horvat"

        worksheet.Cells("B1").Value = "Salary"
        worksheet.Cells("B2").Value = 3600
        worksheet.Cells("B3").Value = 2580
        worksheet.Cells("B4").Value = 3200
        worksheet.Cells("B5").Value = 4100

        ' Select data.
        excelChart.SelectData(worksheet.Cells.GetSubrange("A1:B5"), True)

        document.Save("Created Chart.%OutputFileType%")

    End Sub
End Module

For more information about charts, visit the Chart Components and Chart Formatting examples.

Update chart

The following example shows how you can update line chart data in a Word document.

Word document with updated chart element — Screenshot of Word document with updated chart

C#
VB.NET

View on GitHub

using System.Linq;
using GemBox.Document;
using GemBox.Spreadsheet;
using GemBox.Spreadsheet.Charts;

class Program
{
    static void Main()
    {
        // If using the Professional version, put your GemBox.Document serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY");

        // If using the Professional version, put your GemBox.Spreadsheet serial key below.
        SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY");

        var document = DocumentModel.Load("%#Chart.docx%");

        // Get Word chart.
        var chart = (Chart)document.GetChildElements(true, ElementType.Chart).First();

        // Get underlying Excel chart and cast it as LineChart.
        var lineChart = (LineChart)chart.ExcelChart;

        // Get underlying Excel sheet and add new cell values.
        var sheet = lineChart.Worksheet;
        sheet.Cells["D1"].Value = "Series 3";
        sheet.Cells["D2"].Value = 8.6;
        sheet.Cells["D3"].Value = 5;
        sheet.Cells["D4"].Value = 7;
        sheet.Cells["D5"].Value = 9;

        // Add new line series to the LineChart.
        lineChart.Series.Add(sheet.Cells["D1"].StringValue, "Sheet1!D2:D5");

        document.Save("Updated Chart.%OutputFileType%");
    }
}

Imports System.Linq
Imports GemBox.Document
Imports GemBox.Spreadsheet
Imports GemBox.Spreadsheet.Charts

Module Program

    Sub Main()

        ' If using the Professional version, put your GemBox.Document serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY")

        ' If using the Professional version, put your GemBox.Spreadsheet serial key below.
        SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY")

        Dim document = DocumentModel.Load("%#Chart.docx%")

        ' Get Word chart.
        Dim chart = DirectCast(document.GetChildElements(True, ElementType.Chart).First(), Chart)

        ' Get underlying Excel chart and cast it as LineChart.
        Dim lineChart = DirectCast(chart.ExcelChart, LineChart)

        ' Get underlying Excel sheet and add new cell values.
        Dim sheet = lineChart.Worksheet
        sheet.Cells("D1").Value = "Series 3"
        sheet.Cells("D2").Value = 8.6
        sheet.Cells("D3").Value = 5
        sheet.Cells("D4").Value = 7
        sheet.Cells("D5").Value = 9

        ' Add new line series to the LineChart.
        lineChart.Series.Add(sheet.Cells("D1").StringValue, "Sheet1!D2:D5")

        document.Save("Updated Chart.%OutputFileType%")

    End Sub
End Module

Some chart types are not supported through an API (like 3D charts) and won't be represented with Chart object.

You can find a list of supported chart types on GemBox.Spreadsheet's Charts help page.

Create chart from array data

Usually, the chart's data is provided as a reference to a worksheet's cell range or a named range. But you can also directly assign an array of numeric values that you want to plot.

Using array data may in some cases be an easier and more convenient way to work with charts, such charts are independent of their parent worksheet. However, note that you cannot add or modify such series with Microsoft Word.

The following example shows how to create chart series using array values directly.

Word document with chart that has values directly in its series — Screenshot of chart series with direct values

C#
VB.NET

View on GitHub

using GemBox.Document;
using GemBox.Spreadsheet.Charts;

class Program
{
    static void Main()
    {
        // If using the Professional version, put your GemBox.Document serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY");

        // If using the Professional version, put your GemBox.Spreadsheet serial key below.
        SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY");

        var document = new DocumentModel();

        var chart = new Chart(document, GemBox.Document.ChartType.Column,
            new FloatingLayout(
                new HorizontalPosition(HorizontalPositionType.Center, HorizontalPositionAnchor.Margin),
                new VerticalPosition(VerticalPositionType.Top, VerticalPositionAnchor.Paragraph),
                new Size(10, 5, GemBox.Document.LengthUnit.Centimeter)));

        document.Sections.Add(
            new Section(document,
                new Paragraph(document, chart)));

        // Get underlying Excel chart.
        var columnChart = (ColumnChart)chart.ExcelChart;

        // Set chart's category labels from array.
        columnChart.SetCategoryLabels(new string[] { "Columns 1", "Columns 2", "Columns 3" });

        // Add chart's series from arrays.
        columnChart.Series.Add("Values 1", new double[] { 3.4, 1.1, 3.7 });
        columnChart.Series.Add("Values 2", new double[] { 4.4, 3.9, 3.5 });
        columnChart.Series.Add("Values 3", new double[] { 2.9, 4.1, 1.9 });

        document.Save("Created Chart from Array.%OutputFileType%");
    }
}

Imports GemBox.Document
Imports GemBox.Spreadsheet.Charts

Module Program

    Sub Main()

        ' If using the Professional version, put your GemBox.Document serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY")

        ' If using the Professional version, put your GemBox.Spreadsheet serial key below.
        SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY")

        Dim document As New DocumentModel()

        Dim chart As New Chart(document, GemBox.Document.ChartType.Column,
            New FloatingLayout(
                New HorizontalPosition(HorizontalPositionType.Center, HorizontalPositionAnchor.Margin),
                New VerticalPosition(VerticalPositionType.Top, VerticalPositionAnchor.Paragraph),
                New Size(10, 5, GemBox.Document.LengthUnit.Centimeter)))

        document.Sections.Add(
            New Section(document,
                New Paragraph(document, chart)))

        ' Get underlying Excel chart.
        Dim columnChart = DirectCast(chart.ExcelChart, ColumnChart)

        ' Set chart's category labels from array.
        columnChart.SetCategoryLabels(New String() {"Columns 1", "Columns 2", "Columns 3"})

        ' Add chart's series from arrays.
        columnChart.Series.Add("Values 1", New Double() {3.4, 1.1, 3.7})
        columnChart.Series.Add("Values 2", New Double() {4.4, 3.9, 3.5})
        columnChart.Series.Add("Values 3", New Double() {2.9, 4.1, 1.9})

        document.Save("Created Chart from Array.%OutputFileType%")

    End Sub
End Module

Export chart

To export a document with a chart to PDF or image format using GemBox.Document, you need to enable WPF. To enable WPF, you need to use a Windows-specific TFM in the project file, and you need to have .NET Windows Desktop Runtime installed.

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net7.0-windows</TargetFramework>
  </PropertyGroup>

  <PropertyGroup>
    <UseWPF>true</UseWPF>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="GemBox.Document" Version="*" />
    <PackageReference Include="GemBox.Spreadsheet" Version="*" />
  </ItemGroup>

</Project>

However, using GemBox.Pdf, you can save documents with charts to PDF without using WPF. This is currently the only way to save Word files with charts to PDF on Linux or macOS. The code below demonstrates how to do that.

C#
VB.NET

View on GitHub

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using GemBox.Document;
using GemBox.Pdf;
using GemBox.Pdf.Content;
using GemBox.Spreadsheet;
using GemBox.Spreadsheet.Charts;

class Program
{
    static void Main()
    {
        // If using the Professional versions, put your serial keys below.
        GemBox.Document.ComponentInfo.SetLicense("FREE-LIMITED-KEY");
        GemBox.Pdf.ComponentInfo.SetLicense("FREE-LIMITED-KEY");
        GemBox.Spreadsheet.SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY");

        var document = DocumentModel.Load("%InputFileName%");
        var placeholdersMapping = ReplaceChartsWithPlaceholders(document);
        document.Save("Chart.pdf");

        using (var pdf = PdfDocument.Load("Chart.pdf"))
        {
            ReplacePlaceholdersWithCharts(pdf, placeholdersMapping);
            pdf.Save();
        }
    }

    static readonly string PlaceholderNameFormat = "GemBox_Chart_Placeholder_{0}";
    static readonly Regex PlaceholderNameRegex = new Regex("GemBox_Chart_Placeholder_\\d+");
    static readonly MemoryStream PlaceholderImage = new MemoryStream(File.ReadAllBytes("%#placeholder.png%"));

    static Dictionary<string, MemoryStream> ReplaceChartsWithPlaceholders(DocumentModel document)
    {
        var placeholdersMapping = new Dictionary<string, MemoryStream>();
        int counter = 0;

        foreach (Chart chart in document.GetChildElements(true, ElementType.Chart).Reverse())
        {
            // Replace Word chart with placeholder image that has specific title.
            var placeholder = new Picture(document, PlaceholderImage, PictureFormat.Png, chart.Layout);
            string placeholderName = string.Format(PlaceholderNameFormat, ++counter);
            placeholder.Metadata.Title = placeholderName;
            chart.Content.Start.InsertRange(placeholder.Content);
            chart.Content.Delete();

            // Retrieve Excel chart and export it as PDF.
            var excelChart = (ExcelChart)chart.ExcelChart;
            excelChart.Position.Width = chart.Layout.Size.Width;
            excelChart.Position.Height = chart.Layout.Size.Height;
            var chartAsPdfStream = new MemoryStream();
            excelChart.Format().Save(chartAsPdfStream, GemBox.Spreadsheet.SaveOptions.PdfDefault);

            // Map PDF that contains Excel chart to placeholder name.
            placeholdersMapping.Add(placeholderName, chartAsPdfStream);
        }

        return placeholdersMapping;
    }

    static void ReplacePlaceholdersWithCharts(PdfDocument pdfDocument, Dictionary<string, MemoryStream> placeholdersMapping)
    {
        foreach (var page in pdfDocument.Pages)
        {
            // Find placeholders by searching for images with specific title.
            var placeholders = FindPlaceholders(page);

            foreach (var placeholder in placeholders)
            {
                if (!placeholdersMapping.TryGetValue(placeholder.Key, out MemoryStream chartAsPdfStream))
                    continue;

                PdfImageContent image = placeholder.Value.Item1;
                PdfQuad bounds = placeholder.Value.Item2;

                // Replace placeholder image with PDF that contains Excel chart.
                using (var excelDocument = PdfDocument.Load(chartAsPdfStream))
                {
                    var form = excelDocument.Pages[0].ConvertToForm(pdfDocument);
                    var formContentGroup = page.Content.Elements.AddGroup();
                    var formContent = formContentGroup.Elements.AddForm(form);
                    formContent.Transform = PdfMatrix.CreateTranslation(bounds.Left, bounds.Bottom);
                }

                image.Collection.Remove(image);
            }
        }
    }

    static Dictionary<string, Tuple<PdfImageContent, PdfQuad>> FindPlaceholders(PdfPage page)
    {
        var placeholders = new Dictionary<string, Tuple<PdfImageContent, PdfQuad>>();
        var enumerator = page.Content.Elements.All(page.Transform).GetEnumerator();
        while (enumerator.MoveNext())
        {
            var element = enumerator.Current;
            if (element.ElementType != PdfContentElementType.Image)
                continue;

            var imageElement = (PdfImageContent)element;
            var metadata = imageElement.Image.Metadata?.Value;
            if (metadata == null)
                continue;

            var match = PlaceholderNameRegex.Match(metadata);
            if (!match.Success)
                continue;

            var bounds = imageElement.Bounds;
            enumerator.Transform.Transform(ref bounds);
            placeholders.Add(match.Value, Tuple.Create(imageElement, bounds));
        }

        return placeholders;
    }
}

Imports System
Imports System.Collections.Generic
Imports System.IO
Imports System.Linq
Imports System.Text.RegularExpressions
Imports GemBox.Document
Imports GemBox.Pdf
Imports GemBox.Pdf.Content
Imports GemBox.Spreadsheet
Imports GemBox.Spreadsheet.Charts

Module Program

    Sub Main()

        ' If using the Professional versions, put your serial keys below.
        GemBox.Document.ComponentInfo.SetLicense("FREE-LIMITED-KEY")
        GemBox.Pdf.ComponentInfo.SetLicense("FREE-LIMITED-KEY")
        GemBox.Spreadsheet.SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY")

        Dim document = DocumentModel.Load("%InputFileName%")
        Dim placeholdersMapping = ReplaceChartsWithPlaceholders(document)
        document.Save("Chart.pdf")

        Using pdf = PdfDocument.Load("Chart.pdf")
            ReplacePlaceholdersWithCharts(pdf, placeholdersMapping)
            pdf.Save()
        End Using

    End Sub

    ReadOnly PlaceholderNameFormat As String = "GemBox_Chart_Placeholder_{0}"
    ReadOnly PlaceholderNameRegex As Regex = New Regex("GemBox_Chart_Placeholder_\d+")
    ReadOnly PlaceholderImage As MemoryStream = New MemoryStream(File.ReadAllBytes("%#placeholder.png%"))

    Function ReplaceChartsWithPlaceholders(document As DocumentModel) As Dictionary(Of String, MemoryStream)
        Dim placeholdersMapping = New Dictionary(Of String, MemoryStream)()
        Dim counter As Integer = 0

        For Each chart As Chart In document.GetChildElements(True, ElementType.Chart).Reverse()
            ' Replace Word chart with placeholder image that has specific title.
            Dim placeholder = New Picture(document, PlaceholderImage, PictureFormat.Png, chart.Layout)
            counter += 1
            Dim placeholderName As String = String.Format(PlaceholderNameFormat, counter)
            placeholder.Metadata.Title = placeholderName
            chart.Content.Start.InsertRange(placeholder.Content)
            chart.Content.Delete()

            ' Retrieve Excel chart and export it as PDF.
            Dim excelChart = CType(chart.ExcelChart, ExcelChart)
            excelChart.Position.Width = chart.Layout.Size.Width
            excelChart.Position.Height = chart.Layout.Size.Height
            Dim chartAsPdfStream = New MemoryStream()
            excelChart.Format().Save(chartAsPdfStream, GemBox.Spreadsheet.SaveOptions.PdfDefault)

            ' Map PDF that contains Excel chart to placeholder name.
            placeholdersMapping.Add(placeholderName, chartAsPdfStream)
        Next

        Return placeholdersMapping
    End Function

    Sub ReplacePlaceholdersWithCharts(pdfDocument As PdfDocument, placeholdersMapping As Dictionary(Of String, MemoryStream))
        Dim chartAsPdfStream As MemoryStream = Nothing

        For Each page In pdfDocument.Pages
            ' Find placeholders by searching for images with specific title.
            Dim placeholders = FindPlaceholders(page)

            For Each placeholder In placeholders
                If Not placeholdersMapping.TryGetValue(placeholder.Key, chartAsPdfStream) Then Continue For

                Dim image As PdfImageContent = placeholder.Value.Item1
                Dim bounds As PdfQuad = placeholder.Value.Item2

                ' Replace placeholder image with PDF that contains Excel chart.
                Using excelDocument = PdfDocument.Load(chartAsPdfStream)
                    Dim form = excelDocument.Pages(0).ConvertToForm(pdfDocument)
                    Dim formContentGroup = page.Content.Elements.AddGroup()
                    Dim formContent = formContentGroup.Elements.AddForm(form)
                    formContent.Transform = PdfMatrix.CreateTranslation(bounds.Left, bounds.Bottom)
                End Using

                image.Collection.Remove(image)
            Next
        Next
    End Sub

    Function FindPlaceholders(page As PdfPage) As Dictionary(Of String, Tuple(Of PdfImageContent, PdfQuad))
        Dim placeholders = New Dictionary(Of String, Tuple(Of PdfImageContent, PdfQuad))()
        Dim enumerator = page.Content.Elements.All(page.Transform).GetEnumerator()

        While enumerator.MoveNext()

            Dim element = enumerator.Current
            If element.ElementType <> PdfContentElementType.Image Then Continue While

            Dim imageElement = CType(element, PdfImageContent)
            Dim metadata = imageElement.Image.Metadata?.Value
            If metadata Is Nothing Then Continue While

            Dim match = PlaceholderNameRegex.Match(metadata)
            If Not match.Success Then Continue While

            Dim bounds = imageElement.Bounds
            enumerator.Transform.Transform(bounds)
            placeholders.Add(match.Value, Tuple.Create(imageElement, bounds))

        End While

        Return placeholders
    End Function

End Module

Next steps

GemBox.Document is a .NET component that enables you to read, write, edit, convert, and print document files from your .NET applications using one simple API. How about testing it today?

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Published: October 23, 2019 | Modified: March 30, 2023 | Author: Marko Kozlina

Word Charts in C# and VB.NET

Create chart

Update chart

Create chart from array data

Export chart

See also

Next steps