Format Excel chart data label in C#, VB.NET

using Syncfusion.XlsIO;

Imports Syncfusion.XlsIO

using (ExcelEngine excelEngine = new ExcelEngine())
{
//Instantiate the application object
IApplication application = excelEngine.Excel;
 
//Add a workbook
IWorkbook workbook = application.Workbooks.Create(1);
 
//The first worksheet object in the worksheets collection is accessed
IWorksheet worksheet = workbook.Worksheets[0];
worksheet.Name = "First Chart";
 
//Entering the chart data
worksheet.Range["A1"].Text = "Texas books Unit sales";
worksheet.Range["A1:D1"].Merge();
worksheet.Range["A1"].CellStyle.Font.Bold = true;
 
worksheet.Range["B2"].Text = "Jan";
worksheet.Range["C2"].Text = "Feb";
worksheet.Range["D2"].Text = "Mar";
 
worksheet.Range["A3"].Text = "Austin";
worksheet.Range["A4"].Text = "Dallas";
worksheet.Range["A5"].Text = "Houston";
worksheet.Range["A6"].Text = "San Antonio";
 
worksheet.Range["B3"].Number = 53.75;
worksheet.Range["B4"].Number = 52.85;
worksheet.Range["B5"].Number = 59.77;
worksheet.Range["B6"].Number = 96.15;
 
worksheet.Range["C3"].Number = 79.79;
worksheet.Range["C4"].Number = 59.22;
worksheet.Range["C5"].Number = 10.09;
worksheet.Range["C6"].Number = 73.02;
 
worksheet.Range["D3"].Number = 26.72;
worksheet.Range["D4"].Number = 33.71;
worksheet.Range["D5"].Number = 45.81;
worksheet.Range["D6"].Number = 12.17;
 
//Adding a New (Embedded chart) to the worksheet 
IChartShape shape = worksheet.Charts.Add();
shape.ChartType = ExcelChartType.Column_Clustered;
shape.DataRange = worksheet.Range["B3:D6"];
shape.IsSeriesInRows = false;
shape.PrimaryCategoryAxis.Title = "City";
shape.PrimaryCategoryAxis.CategoryLabels = worksheet["A3:A6"];
shape.PrimaryValueAxis.Title = "Sales (in Dollars)";
shape.ChartTitle = "Texas Books Unit Sales";
shape.HasDataTable = true;
 
// Displaying the values in the series
IChartDataPoint point = shape.Series[0].DataPoints.DefaultDataPoint;
IChartDataLabels labels = point.DataLabels;
 
// Formatting the labels
labels.IsValue = true;
labels.Bold = true;
labels.FrameFormat.Border.LinePattern = ExcelChartLinePattern.DashDotDot;
labels.Size = 20;
labels.Italic = true;
labels.Color = ExcelKnownColors.Red;
 
//Save the file
workbook.SaveAs("Output.xlsx");
 
System.Diagnostics.Process.Start("Output.xlsx");
}

Using excelEngine As ExcelEngine = New ExcelEngine()
'Instantiate the application object
Dim application As IApplication = excelEngine.Excel
 
'Add a workbook
Dim workbook As IWorkbook = application.Workbooks.Create(1)
 
'The first worksheet object in the worksheets collection is accessed
Dim worksheet As IWorksheet = workbook.Worksheets(0)
worksheet.Name = "First Chart"
 
'Entering the chart data
worksheet.Range("A1").Text = "Texas books Unit sales"
worksheet.Range("A1:D1").Merge()
worksheet.Range("A1").CellStyle.Font.Bold = True
 
worksheet.Range("B2").Text = "Jan"
worksheet.Range("C2").Text = "Feb"
worksheet.Range("D2").Text = "Mar"
 
worksheet.Range("A3").Text = "Austin"
worksheet.Range("A4").Text = "Dallas"
worksheet.Range("A5").Text = "Houston"
worksheet.Range("A6").Text = "San Antonio"
 
worksheet.Range("B3").Number = 53.75
worksheet.Range("B4").Number = 52.85
worksheet.Range("B5").Number = 59.77
worksheet.Range("B6").Number = 96.15
 
worksheet.Range("C3").Number = 79.79
worksheet.Range("C4").Number = 59.22
worksheet.Range("C5").Number = 10.09
worksheet.Range("C6").Number = 73.02
 
worksheet.Range("D3").Number = 26.72
worksheet.Range("D4").Number = 33.71
worksheet.Range("D5").Number = 45.81
worksheet.Range("D6").Number = 12.17
 
'Adding a New (Embedded chart) to the Worksheet 
Dim shape As IChartShape = worksheet.Charts.Add()
shape.ChartType = ExcelChartType.Column_Clustered
shape.DataRange = worksheet.Range("B3:D6")
shape.IsSeriesInRows = False
shape.PrimaryCategoryAxis.Title = "City"
shape.PrimaryCategoryAxis.CategoryLabels = worksheet("A3:A6")
shape.PrimaryValueAxis.Title = "Sales (in Dollars)"
shape.ChartTitle = "Texas Books Unit Sales"
shape.HasDataTable = True
 
'Displaying the values in the series
Dim point As IChartDataPoint = shape.Series(0).DataPoints.DefaultDataPoint
Dim labels As IChartDataLabels = point.DataLabels
 
'Formatting the labels
labels.IsValue = True
labels.Bold = True
labels.FrameFormat.Border.LinePattern = ExcelChartLinePattern.DashDotDot
labels.Size = 20
labels.Italic = True
labels.Color = ExcelKnownColors.Red
 
'Save the file
workbook.SaveAs("Output.xlsx")
 
System.Diagnostics.Process.Start("Output.xlsx")
End Using