Chart Data Labels in PowerPoint

30 Aug 202412 minutes to read

Data Labels on a chart make it easier to understand. They show important information about the lines or points on the chart. Using Presentation, you can customize the data labels in the chart.

Enable Data Labels in Chart

The following code snippet illustrates how to visible the data label in chart.

C# [Cross-platform]

//Enable the datalabel in chart.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.IsValue = true;

C# [Windows-specific]

//Enable the datalabel in chart.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.IsValue = true;

VB.NET [Windows-specific]

' Enable the datalabel in chart.
chart.Series(0).DataPoints.DefaultDataPoint.DataLabels.IsValue = True

Customize the Data Labels

The following code snippet illustrates how to customize the data label in chart.

C# [Cross-platform]

// Set the font size of the data labels.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.Size = 8;
// Change the color of the data labels.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.Color = OfficeKnownColors.Red;
// Make the data labels bold.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.Bold = true;
// Set the font name for the data labels.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.FontName = "calibri";
// Make the data labels italic.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.Italic = true;

C# [Windows-specific]

// Set the font size of the data labels.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.Size = 8;
// Change the color of the data labels.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.Color = OfficeKnownColors.Red;
// Make the data labels bold.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.Bold = true;
// Set the font name for the data labels.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.FontName = "calibri";
// Make the data labels italic.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.Italic = true;

VB.NET [Windows-specific]

' Set the font size of the data labels.
chart.Series(0).DataPoints.DefaultDataPoint.DataLabels.Size = 8
' Change the color of the data labels.
chart.Series(0).DataPoints.DefaultDataPoint.DataLabels.Color = OfficeKnownColors.Red
' Make the data labels bold.
chart.Series(0).DataPoints.DefaultDataPoint.DataLabels.Bold = True
' Set the font name for the data labels.
chart.Series(0).DataPoints.DefaultDataPoint.DataLabels.FontName = "calibri"
' Make the data labels italic.
chart.Series(0).DataPoints.DefaultDataPoint.DataLabels.Italic = True

Set the Position of Data Labels

The following code snippet illustrates how to set the position of the data label in chart.

C# [Cross-platform]

// Set the position of data labels for the first series.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.Position = OfficeDataLabelPosition.Center;

C# [Windows-specific]

// Set the position of data labels for the first series.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.Position = OfficeDataLabelPosition.Center;

VB.NET [Windows-specific]

' Set the position of data labels for the first series.
chart.Series(0).DataPoints.DefaultDataPoint.DataLabels.Position = OfficeDataLabelPosition.Center

The complete code snippet illustrating the above options is shown below.

C# [Cross-platform]

FileStream fileStreamPath = new FileStream("Data/Template.pptx", FileMode.Open, FileAccess.Read, FileShare.ReadWrite);

//Open an existing PowerPoint Presentation.
using (IPresentation pptxDoc = Presentation.Open(fileStreamPath))
{
    //Gets the first slide.
    ISlide slide = pptxDoc.Slides[0];
    //Gets the chart in slide.
    IPresentationChart chart = slide.Shapes[0] as IPresentationChart;

    for (int i = 0; i < chart.Series.Count; i++)
    {
        //Enable the datalabel in chart.
        chart.Series[i].DataPoints.DefaultDataPoint.DataLabels.IsValue = true;

        // Set the font size of the data labels.
        chart.Series[i].DataPoints.DefaultDataPoint.DataLabels.Size = 10;
        // Change the color of the data labels. 
        chart.Series[i].DataPoints.DefaultDataPoint.DataLabels.Color = OfficeKnownColors.Black;
        // Make the data labels bold.
        chart.Series[i].DataPoints.DefaultDataPoint.DataLabels.Bold = true;
        // Set the position of data labels for the first series.
        chart.Series[i].DataPoints.DefaultDataPoint.DataLabels.Position = OfficeDataLabelPosition.Center;
    }
    using (FileStream outputStream = new FileStream("Result.pptx", FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite))
    {
        //Save the PowerPoint Presentation.
        pptxDoc.Save(outputStream);
    }
}

C# [Windows-specific]

//Open an existing PowerPoint Presentation.
using (IPresentation pptxDoc = Presentation.Open("Template.pptx"))
{
    //Gets the first slide.
    ISlide slide = pptxDoc.Slides[0];
    //Gets the chart in slide.
    IPresentationChart chart = slide.Shapes[0] as IPresentationChart;

    for (int i = 0; i < chart.Series.Count; i++)
    {
        //Enable the datalabel in chart.
        chart.Series[i].DataPoints.DefaultDataPoint.DataLabels.IsValue = true;

        // Set the font size of the data labels.
        chart.Series[i].DataPoints.DefaultDataPoint.DataLabels.Size = 10;
        // Change the color of the data labels. 
        chart.Series[i].DataPoints.DefaultDataPoint.DataLabels.Color = OfficeKnownColors.Black;
        // Make the data labels bold.
        chart.Series[i].DataPoints.DefaultDataPoint.DataLabels.Bold = true;
        // Set the position of data labels for the first series.
        chart.Series[i].DataPoints.DefaultDataPoint.DataLabels.Position = OfficeDataLabelPosition.Center;
    }
    //Save the PowerPoint Presentation.
    pptxDoc.Save("Result.pptx");
}

VB.NET [Windows-specific]

' Open an existing PowerPoint Presentation.
Using pptxDoc As IPresentation = Presentation.Open("Template.pptx")
    ' Gets the first slide.
    Dim slide As ISlide = pptxDoc.Slides(0)
    ' Gets the chart in the slide.
    Dim chart As IPresentationChart = TryCast(slide.Shapes(0), IPresentationChart)

    For i As Integer = 0 To chart.Series.Count - 1
        ' Enable the datalabel in the chart.
        chart.Series(i).DataPoints.DefaultDataPoint.DataLabels.IsValue = True

        ' Set the font size of the data labels.
        chart.Series(i).DataPoints.DefaultDataPoint.DataLabels.Size = 10
        ' Change the color of the data labels. 
        chart.Series(i).DataPoints.DefaultDataPoint.DataLabels.Color = OfficeKnownColors.Black
        ' Make the data labels bold.
        chart.Series(i).DataPoints.DefaultDataPoint.DataLabels.Bold = True
        ' Set the position of data labels for the first series.
        chart.Series(i).DataPoints.DefaultDataPoint.DataLabels.Position = OfficeDataLabelPosition.Center
    Next

    ' Save the PowerPoint Presentation.
    pptxDoc.Save("Result.pptx")
End Using

You can download a complete working sample from GitHub.

Resize the Data Labels

The following code snippet illustrates how to resize the data label in chart.

C# [Cross-platform]

//Manually resizing data label area using Layout.
chart.Series[0].DataPoints[0].DataLabels.Layout.Left = 3;
chart.Series[0].DataPoints[0].DataLabels.Layout.Top = 3;

//Manually resizing data label area using Manual Layout.
chart.Series[0].DataPoints[0].DataLabels.Layout.ManualLayout.Left = 3;
chart.Series[0].DataPoints[0].DataLabels.Layout.ManualLayout.Top = 3;

C# [Windows-specific]

//Manually resizing data label area using Layout.
chart.Series[0].DataPoints[0].DataLabels.Layout.Left = 3;
chart.Series[0].DataPoints[0].DataLabels.Layout.Top = 3;

//Manually resizing data label area using Manual Layout.
chart.Series[0].DataPoints[0].DataLabels.Layout.ManualLayout.Left = 3;
chart.Series[0].DataPoints[0].DataLabels.Layout.ManualLayout.Top = 3;

VB.NET [Windows-specific]

' Manually resizing data label area using Layout.
chart.Series(0).DataPoints(0).DataLabels.Layout.Left = 3
chart.Series(0).DataPoints(0).DataLabels.Layout.Top = 3

' Manually resizing data label area using Manual Layout.
chart.Series(0).DataPoints(0).DataLabels.Layout.ManualLayout.Left = 3
chart.Series(0).DataPoints(0).DataLabels.Layout.ManualLayout.Top = 3

Show Leader lines

The leader lines can be shown in a chart through ShowLeaderLines API which can be set to all data labels by enabling the leader lines for DefaultDataPoint.

The following code illustrates how to enable the leader lines for all data labels in the chart.

C# [Cross-platform]

// Enable the leader lines in Chart.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.ShowLeaderLines = true;

C# [Windows-specific]

// Enable the leader lines in Chart.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.ShowLeaderLines = true;

VB.NET [Windows-specific]

' Enable the leader lines in Chart.
chart.Series[0].DataPoints.DefaultDataPoint.DataLabels.ShowLeaderLines = true;

You can download a complete working sample from GitHub.

See Also

• How to change text of data labels for Chart in Presentation