How to set trendlines for Excel chart series in C#, VB.NET?
This article explains how to set a shadow to the plot area in a chart using WinForms XlsIO.
What is Plot Area?
The plot area in a chart or graph refers to the area of the chart that graphically displays the data being charted. The plot area of a 2D chart contains the data markers, gridlines, data labels, trendlines, and optional chart items placed in the chart area. Whereas the plot area of a 3D chart contains all the above items along with walls, floor, axes, axis titles, and tick-mark labels in the chart.

Shadow for plot area set using XlsIO
Code snippet to set shadow to plot area in chart using XlsIO
// Set shadow to plot area chart.PlotArea.Shadow.ShadowColor = System.Drawing.Color.DarkOrange; chart.PlotArea.Shadow.Size = 100; chart.PlotArea.Shadow.Angle = 45; chart.PlotArea.Shadow.Distance = 10;
Steps to add shadow to plot area in chart
- Initialize chart
Create a chart object by calling the worksheet.Charts.Add method and specify the chart type to ExcelChartType.Line enum value.
// Create the chart IChartShape chart = worksheet.Charts.Add(); // Set chart type to Line chart.ChartType = ExcelChartType.Line;
- Assign data
Set a range of data from the worksheet to chart’s DataRange property. To plot the series values in column and categories in row, set chart’s IsSeriesInRows property to false.
// Set region of chart data chart.DataRange = worksheet["A1:D6"]; // Set chart series in column for assigned data region chart.IsSeriesInRows = false;
- Apply chart elements
Add basic chart elements like the chart title, legend and data labels.
- ChartTitle of the chart object.
- Set TRUE to the chart’s HasLegend property, to show the legend.
// Set chart Title chart.ChartTitle = "Line Chart"; // Set Legend chart.HasLegend = true; chart.Legend.Position = ExcelLegendPosition.Bottom; // Set dataLabels IChartSerie serie1 = chart.Series[0];
serie1.DataPoints.DefaultDataPoint.DataLabels.IsValue = true;
- Set shadow to plot area
Set shadow to plot area in chart using properties in IShadow.
// Set shadow to plot area chart.PlotArea.Shadow.ShadowColor = System.Drawing.Color.DarkOrange; chart.PlotArea.Shadow.Size = 100; chart.PlotArea.Shadow.Angle = 45; chart.PlotArea.Shadow.Distance = 10;
Applicable properties for a shadow of plot area in chart
Basic properties applicable for a shadow of plot area in a chart
1. Angle
2. Blur
3. Distance
4. HasCustomShadowStyle
5. ShadowColor
6. ShadowInnerPresets
7. ShadowOuterPresets
8. ShadowPrespectivePresets
9. Size
10. Transperency
We can set shadow to plot area in chart using CustomShadowStyles method as well.
The following C#/VB complete code snippet explains how to set shadow to plot area in chart using XlsIO.
C#
using Syncfusion.XlsIO;
using System.Reflection;
using System.IO;
namespace ChartSample
{
class Program
{
static void Main(string[] args)
{
using (ExcelEngine excelEngine = new ExcelEngine())
{
IApplication application = excelEngine.Excel;
application.DefaultVersion = ExcelVersion.Excel2016;
// Open existing workbook with data entered
Assembly assembly = typeof(Program).GetTypeInfo().Assembly;
Stream fileStream = assembly.GetManifestResourceStream("ChartSample.InputTemplate.xlsx");
IWorkbook workbook = application.Workbooks.Open(fileStream);
IWorksheet worksheet = workbook.Worksheets[0];
// Initialize chart
IChartShape chart = worksheet.Charts.Add();
chart.ChartType = ExcelChartType.Line;
// Assign data
chart.DataRange = worksheet["A1:D6"];
chart.IsSeriesInRows = false;
// Apply chart elements
// Set chart title
chart.ChartTitle = "Line Chart";
// Set legend
chart.HasLegend = true;
chart.Legend.Position = ExcelLegendPosition.Bottom;
// Set dataLabels
IChartSerie serie1 = chart.Series[0];
IChartSerie serie2 = chart.Series[1];
IChartSerie serie3 = chart.Series[2];
serie1.DataPoints.DefaultDataPoint.DataLabels.IsValue = true;
serie2.DataPoints.DefaultDataPoint.DataLabels.IsValue = true;
serie3.DataPoints.DefaultDataPoint.DataLabels.IsValue = true;
// Set shadow to plot area
chart.PlotArea.Shadow.ShadowColor = System.Drawing.Color.DarkOrange;
chart.PlotArea.Shadow.Size = 100;
chart.PlotArea.Shadow.Angle = 45;
chart.PlotArea.Shadow.Distance = 10;
// Positioning the chart in the worksheet
chart.TopRow = 8;
chart.LeftColumn = 1;
chart.BottomRow = 23;
chart.RightColumn = 8;
// Saving the workbook
Stream stream = File.Create("Output.xlsx");
workbook.SaveAs(stream);
}
}
}
}
VB
Imports Syncfusion.XlsIO
Imports System.Reflection
Imports System.IO
Namespace ChartSample
Class Program
Private Shared Sub Main(ByVal args() As String)
Dim excelEngine As ExcelEngine = New ExcelEngine
Dim application As IApplication = excelEngine.Excel
application.DefaultVersion = ExcelVersion.Excel2016
'Open existing workbook with data entered
Dim assembly As Assembly = GetType(Program).GetTypeInfo.Assembly
Dim fileStream As Stream = assembly.GetManifestResourceStream("ChartSample.InputTemplate.xlsx")
Dim workbook As IWorkbook = application.Workbooks.Open(fileStream)
Dim worksheet As IWorksheet = workbook.Worksheets(0)
'Initialize chart
Dim chart As IChartShape = worksheet.Charts.Add
chart.ChartType = ExcelChartType.Line
'Assign data
chart.DataRange = worksheet("A1:D6")
chart.IsSeriesInRows = False
'Apply chart elements
'Set chart title
chart.ChartTitle = "Line Chart"
'Set legend
chart.HasLegend = True
chart.Legend.Position = ExcelLegendPosition.Bottom
'Set datalabels
Dim serie1 As IChartSerie = chart.Series(0)
Dim serie2 As IChartSerie = chart.Series(1)
Dim serie3 As IChartSerie = chart.Series(2)
serie1.DataPoints.DefaultDataPoint.DataLabels.IsValue = True
serie2.DataPoints.DefaultDataPoint.DataLabels.IsValue = True
serie3.DataPoints.DefaultDataPoint.DataLabels.IsValue = True
'Set shadow to plot area
chart.PlotArea.Shadow.ShadowColor = System.Drawing.Color.DarkOrange
chart.PlotArea.Shadow.Size = 100
chart.PlotArea.Shadow.Angle = 45
chart.PlotArea.Shadow.Distance = 10
'Positioning the chart in the worksheet
chart.TopRow = 8
chart.LeftColumn = 1
chart.BottomRow = 23
chart.RightColumn = 8
'Saving the workbook
Dim stream As Stream = File.Create("Output.xlsx")
workbook.SaveAs(stream)
End Sub
End Class
End Namespace
Conclusion
I hope you enjoyed learning about how to set trendlines for Excel chart series in C#, VB.NET.
You can refer to our WinForms Excel’s feature tour page to know about its other groundbreaking feature representations. You can also explore our WinForms Excel documentation to understand how to present and manipulate data.
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