PM> Install-Package Spire.Presentation

using Spire.Presentation;
using Spire.Presentation.Charts;
using Spire.Presentation.Drawing;
using System;
using System.Data;
using System.Drawing;

namespace CombinationChart
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a Presentation instance
            Presentation presentation = new Presentation();

            //Add a column clustered chart to the first slide
            RectangleF rect = new RectangleF(80, 120, 550, 320);
            IChart chart = presentation.Slides[0].Shapes.AppendChart(ChartType.ColumnClustered, rect);

            //Set and format chart title
            chart.ChartTitle.TextProperties.Text = "Monthly Sales Report";
            chart.ChartTitle.TextProperties.IsCentered = true;
            chart.ChartTitle.Height = 30;
            chart.HasTitle = true;

            //Create a datatable and add some data
            DataTable dataTable = new DataTable();
            dataTable.Columns.Add(new DataColumn("Month", Type.GetType("System.String")));
            dataTable.Columns.Add(new DataColumn("Sales", Type.GetType("System.Int32")));
            dataTable.Columns.Add(new DataColumn("Growth rate", Type.GetType("System.Decimal")));
            dataTable.Rows.Add("January", 200, 0.6);
            dataTable.Rows.Add("February", 250, 0.8);
            dataTable.Rows.Add("March", 300, 0.6);
            dataTable.Rows.Add("April", 150, 0.2);
            dataTable.Rows.Add("May", 200, 0.5);
            dataTable.Rows.Add("June", 400, 0.9);

            //Import data from datatable to chart data
            for (int c = 0; c < dataTable.Columns.Count; c++)
            {
                chart.ChartData[0, c].Text = dataTable.Columns[c].Caption;
            }
            for (int r = 0; r < dataTable.Rows.Count; r++)
            {
                object[] datas = dataTable.Rows[r].ItemArray;
                for (int c = 0; c < datas.Length; c++)
                {
                    chart.ChartData[r + 1, c].Value = datas[c];

                }
            }

            //Set series labels
            chart.Series.SeriesLabel = chart.ChartData["B1", "C1"];

            //Set categories labels    
            chart.Categories.CategoryLabels = chart.ChartData["A2", "A7"];

            //Assign data to series values
            chart.Series[0].Values = chart.ChartData["B2", "B7"];
            chart.Series[1].Values = chart.ChartData["C2", "C7"];

            //Change the chart type of series 2 to a line chart with data markers
            chart.Series[1].Type = ChartType.LineMarkers;

            //Plot data of series 2 on the secondary axis
            chart.Series[1].UseSecondAxis = true;

            //Set the number format of the secondary value axis
            chart.SecondaryValueAxis.NumberFormat = "0%";

            //Hide the gridlines of the secondary value axis
            chart.SecondaryValueAxis.MajorGridTextLines.FillType = FillFormatType.None;

            //Set the legend position
            chart.ChartLegend.Position = ChartLegendPositionType.Top;

            //Set overlap
            chart.OverLap = -50;

            //Set gapwidth
            chart.GapWidth = 200;

            //Save the result document
            presentation.SaveToFile("CombinationChart.pptx", FileFormat.Pptx2010);
        }
    }
}

Imports Spire.Presentation
Imports Spire.Presentation.Charts
Imports Spire.Presentation.Drawing
Imports System
Imports System.Data
Imports System.Drawing

Namespace CombinationChart

    Class Program

        Private Shared Sub Main(ByVal args() As String)
            'Create a Presentation instance
            Dim presentation As Presentation = New Presentation

            'Add a column clustered chart to the first slide
            Dim rect As RectangleF = New RectangleF(80, 120, 550, 320)
            Dim chart As IChart = presentation.Slides(0).Shapes.AppendChart(ChartType.ColumnClustered, rect)

            'Set and format chart title
            chart.ChartTitle.TextProperties.Text = "Monthly Sales Report"
            chart.ChartTitle.TextProperties.IsCentered = True
            chart.ChartTitle.Height = 30
            chart.HasTitle = True

            'Create a datatable and add some data
            Dim dataTable As DataTable = New DataTable
            dataTable.Columns.Add(New DataColumn("Month", Type.GetType("System.String")))
            dataTable.Columns.Add(New DataColumn("Sales", Type.GetType("System.Int32")))
            dataTable.Columns.Add(New DataColumn("Growth rate", Type.GetType("System.Decimal")))
            dataTable.Rows.Add("January", 200, 0.6)
            dataTable.Rows.Add("February", 250, 0.8)
            dataTable.Rows.Add("March", 300, 0.6)
            dataTable.Rows.Add("April", 150, 0.2)
            dataTable.Rows.Add("May", 200, 0.5)
            dataTable.Rows.Add("June", 400, 0.9)

            'Import data from datatable to chart data
            Dim c As Integer = 0
            Do While (c < dataTable.Columns.Count)
                chart.ChartData(0, c).Text = dataTable.Columns(c).Caption
                c = (c + 1)
            Loop

            Dim r As Integer = 0
            Do While (r < dataTable.Rows.Count)
                Dim datas() As Object = dataTable.Rows(r).ItemArray
                Dim c As Integer = 0
                Do While (c < datas.Length)
                    chart.ChartData((r + 1), c).Value = datas(c)
                    c = (c + 1)
                Loop

                r = (r + 1)
            Loop

            'Set series labels
            chart.Series.SeriesLabel = chart.ChartData("B1", "C1")

            'Set categories labels    
            chart.Categories.CategoryLabels = chart.ChartData("A2", "A7")

            'Assign data to series values
            chart.Series(0).Values = chart.ChartData("B2", "B7")
            chart.Series(1).Values = chart.ChartData("C2", "C7")

            'Change the chart type of serie 2 to a line chart with data markers
            chart.Series(1).Type = ChartType.LineMarkers

            'Plot data of series 2 on the secondary axis
            chart.Series(1).UseSecondAxis = True

            'Set the number format of the secondary value axis
            chart.SecondaryValueAxis.NumberFormat = "0%"

            'Hide the gridlines of the secondary value axis
            chart.SecondaryValueAxis.MajorGridTextLines.FillType = FillFormatType.None

            'Set the legend position
            chart.ChartLegend.Position = ChartLegendPositionType.Top

            'Set overlap
            chart.OverLap = -50

            'Set gapwidth
            chart.GapWidth = 200

            'Save the result document
            presentation.SaveToFile("CombinationChart.pptx", FileFormat.Pptx2010)
        End Sub
    End Class
End Namespace

PM> Install-Package Spire.XLS

using Spire.Xls;
using Spire.Xls.Collections;

namespace WorksheetName
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a Workbook object
            Workbook workbook = new Workbook();

            // Load an Excel document
            workbook.LoadFromFile("Budget.xlsx");

            // Get all the worksheets in Excel
            WorksheetsCollection worksheets = workbook.Worksheets;

            // Iterate through each worksheet 
            foreach (Worksheet sheet in worksheets)
            {
                // Get worksheet name               
                Console.WriteLine(sheet.Name);
            }
        }
    }
}

using Spire.Xls;
using Spire.Xls.Collections;

namespace HiddenSheetsName
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a Workbook object
            Workbook workbook = new Workbook();

            // Load an Excel document
            workbook.LoadFromFile("E:\\PythonExcel\\Monthly company budget.xlsx");

            // Get all the worksheets in Excel
            WorksheetsCollection worksheets = workbook.Worksheets;

            // Iterate through each worksheet
            foreach (Worksheet sheet in worksheets)
            {
                // Detect the hidden worksheet
                if (sheet.Visibility == WorksheetVisibility.Hidden)
                {
                    // Get the hidden worksheet name
                    Console.WriteLine(sheet.Name);
                }
            }
        }
    }
}