Create, read, and edit Excel files in UWP

22 Dec 202224 minutes to read

Syncfusion Excel library for UWP platform can be used to create, read, edit Excel files. This also convert Excel files to PDF.

Create a simple Excel report

The below steps illustrates creating an simple Invoice formatted Excel document in UWP application.

  1. Create a new C# Blank App (Universal Windows) project.

Create UWP application in Visual Studio

  1. Install the Syncfusion.XlsIO.UWP NuGet package as reference to your .NET Framework applications from NuGet.org.

Add XlsIO reference to the project

  1. Add a new button in the MainPage.xaml as shown below.

    <Page
    x:Class="GettingStarted_UWP.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:GettingStarted_UWP"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
   
    <Grid>
        <Button x:Name="button" Content="Create Document" Click="OnButtonClicked" HorizontalAlignment="Center" VerticalAlignment="Center"/>
    </Grid>
</Page>

  2. Include the following namespaces in the MainPage.xaml.cs file.

    using Syncfusion.XlsIO;
using Windows.Storage.Pickers;
using Windows.Storage;
using Windows.UI;
    Imports Syncfusion.XlsIO
Imports Windows.Storage.Pickers
Imports Windows.Storage
Imports Windows.UI

  3. Include the below code snippet in the click event of the button in MainPage.xaml.cs, to create an Excel file and save the Excel document as a physical file and open the file for viewing.

    //Create an instance of ExcelEngine.
using (ExcelEngine excelEngine = new ExcelEngine())
{
  IApplication application = excelEngine.Excel;
  application.DefaultVersion = ExcelVersion.Xlsx;
   
  //Create a workbook with a worksheet
  IWorkbook workbook = application.Workbooks.Create(1);
   
  //Access first worksheet from the workbook instance.
  IWorksheet worksheet = workbook.Worksheets[0];
  Assembly executingAssembly = typeof(MainPage).GetTypeInfo().Assembly;
  Stream inputStream = executingAssembly.GetManifestResourceStream("GettingStarted_UWP.AdventureCycles-Logo.png");
   
  //Add a picture
  IPictureShape shape = worksheet.Pictures.AddPicture(1, 1, inputStream, 20, 20);
   
  //Disable gridlines in the worksheet
  worksheet.IsGridLinesVisible = false;
   
  //Enter values to the cells from A3 to A5
  worksheet.Range["A3"].Text = "46036 Michigan Ave";
  worksheet.Range["A4"].Text = "Canton, USA";
  worksheet.Range["A5"].Text = "Phone: +1 231-231-2310";
   
  //Make the text bold
  worksheet.Range["A3:A5"].CellStyle.Font.Bold = true;
   
  //Merge cells
  worksheet.Range["D1:E1"].Merge();
   
  //Enter text to the cell D1 and apply formatting.
  worksheet.Range["D1"].Text = "INVOICE";
  worksheet.Range["D1"].CellStyle.Font.Bold = true;
  worksheet.Range["D1"].CellStyle.Font.RGBColor = ColorHelper.FromArgb(0, 42, 118, 189);
  worksheet.Range["D1"].CellStyle.Font.Size = 35;
   
  //Apply alignment in the cell D1
  worksheet.Range["D1"].CellStyle.HorizontalAlignment = ExcelHAlign.HAlignRight;
  worksheet.Range["D1"].CellStyle.VerticalAlignment = ExcelVAlign.VAlignTop;
   
  //Enter values to the cells from D5 to E8
  worksheet.Range["D5"].Text = "INVOICE#";
  worksheet.Range["E5"].Text = "DATE";
  worksheet.Range["D6"].Number = 1028;
  worksheet.Range["E6"].Value = "12/31/2018";
  worksheet.Range["D7"].Text = "CUSTOMER ID";
  worksheet.Range["E7"].Text = "TERMS";
  worksheet.Range["D8"].Number = 564;
  worksheet.Range["E8"].Text = "Due Upon Receipt";
   
  //Apply RGB backcolor to the cells from D5 to E8
  worksheet.Range["D5:E5"].CellStyle.Color = ColorHelper.FromArgb(0, 42, 118, 189);
  worksheet.Range["D7:E7"].CellStyle.Color = ColorHelper.FromArgb(0, 42, 118, 189);
   
  //Apply known colors to the text in cells D5 to E8
  worksheet.Range["D5:E5"].CellStyle.Font.Color = ExcelKnownColors.White;
  worksheet.Range["D7:E7"].CellStyle.Font.Color = ExcelKnownColors.White;
   
  //Make the text as bold from D5 to E8
  worksheet.Range["D5:E8"].CellStyle.Font.Bold = true;
   
  //Apply alignment to the cells from D5 to E8
  worksheet.Range["D5:E8"].CellStyle.HorizontalAlignment = ExcelHAlign.HAlignCenter;
  worksheet.Range["D5:E5"].CellStyle.VerticalAlignment = ExcelVAlign.VAlignCenter;
  worksheet.Range["D7:E7"].CellStyle.VerticalAlignment = ExcelVAlign.VAlignCenter;
  worksheet.Range["D6:E6"].CellStyle.VerticalAlignment = ExcelVAlign.VAlignTop;
   
  //Enter value and applying formatting in the cell A7
  worksheet.Range["A7"].Text = "  BILL TO";
  worksheet.Range["A7"].CellStyle.Color = ColorHelper.FromArgb(0, 42, 118, 189);
  worksheet.Range["A7"].CellStyle.Font.Bold = true;
  worksheet.Range["A7"].CellStyle.Font.Color = ExcelKnownColors.White;
   
  //Apply alignment
  worksheet.Range["A7"].CellStyle.HorizontalAlignment = ExcelHAlign.HAlignLeft;
  worksheet.Range["A7"].CellStyle.VerticalAlignment = ExcelVAlign.VAlignCenter;
   
  //Enter values in the cells A8 to A12 
  worksheet.Range["A8"].Text = "Steyn";
  worksheet.Range["A9"].Text = "Great Lakes Food Market";
  worksheet.Range["A10"].Text = "20 Whitehall Rd";
  worksheet.Range["A11"].Text = "North Muskegon,USA";
  worksheet.Range["A12"].Text = "+1 231-654-0000";
   
  //Create a Hyperlink for e-mail in the cell A13
  IHyperLink hyperlink = worksheet.HyperLinks.Add(worksheet.Range["A13"]);
  hyperlink.Type = ExcelHyperLinkType.Url;
  hyperlink.Address = "Steyn@greatlakes.com";
  hyperlink.ScreenTip = "Send Mail";
   
  //Enter details of products and prices
  worksheet.Range["A15"].Text = "  DESCRIPTION";
  worksheet.Range["C15"].Text = "QTY";
  worksheet.Range["D15"].Text = "UNIT PRICE";
  worksheet.Range["E15"].Text = "AMOUNT";
  worksheet.Range["A16"].Text = "Cabrales Cheese";
  worksheet.Range["A17"].Text = "Chocos";
  worksheet.Range["A18"].Text = "Pasta";
  worksheet.Range["A19"].Text = "Cereals";
  worksheet.Range["A20"].Text = "Ice Cream";
  worksheet.Range["C16"].Number = 3;
  worksheet.Range["C17"].Number = 2;
  worksheet.Range["C18"].Number = 1;
  worksheet.Range["C19"].Number = 4;
  worksheet.Range["C20"].Number = 3;
  worksheet.Range["D16"].Number = 21;
  worksheet.Range["D17"].Number = 54;
  worksheet.Range["D18"].Number = 10;
  worksheet.Range["D19"].Number = 20;
  worksheet.Range["D20"].Number = 30;
  worksheet.Range["D23"].Text = "Total";
   
  //Apply number format
  worksheet.Range["D16:E22"].NumberFormat = "$.00";
  worksheet.Range["E23"].NumberFormat = "$.00";
   
  //Merge column A and B from row 15 to 22
  worksheet.Range["A15:B15"].Merge();
  worksheet.Range["A16:B16"].Merge();
  worksheet.Range["A17:B17"].Merge();
  worksheet.Range["A18:B18"].Merge();
  worksheet.Range["A19:B19"].Merge();
  worksheet.Range["A20:B20"].Merge();
  worksheet.Range["A21:B21"].Merge();
  worksheet.Range["A22:B22"].Merge();
   
  //Apply incremental formula for column Amount by multiplying Qty and UnitPrice
  application.EnableIncrementalFormula = true;
  worksheet.Range["E16:E20"].Formula = "=C16*D16";
   
  //Formula for Sum the total
  worksheet.Range["E23"].Formula = "=SUM(E16:E22)";
   
  //Apply borders
  worksheet.Range["A16:E22"].CellStyle.Borders[ExcelBordersIndex.EdgeTop].LineStyle = ExcelLineStyle.Thin;
  worksheet.Range["A16:E22"].CellStyle.Borders[ExcelBordersIndex.EdgeBottom].LineStyle = ExcelLineStyle.Thin;
  worksheet.Range["A16:E22"].CellStyle.Borders[ExcelBordersIndex.EdgeTop].Color = ExcelKnownColors.Grey_25_percent;
  worksheet.Range["A16:E22"].CellStyle.Borders[ExcelBordersIndex.EdgeBottom].Color = ExcelKnownColors.Grey_25_percent;
  worksheet.Range["A23:E23"].CellStyle.Borders[ExcelBordersIndex.EdgeTop].LineStyle = ExcelLineStyle.Thin;
  worksheet.Range["A23:E23"].CellStyle.Borders[ExcelBordersIndex.EdgeBottom].LineStyle = ExcelLineStyle.Thin;
  worksheet.Range["A23:E23"].CellStyle.Borders[ExcelBordersIndex.EdgeTop].Color = ExcelKnownColors.Black;
  worksheet.Range["A23:E23"].CellStyle.Borders[ExcelBordersIndex.EdgeBottom].Color = ExcelKnownColors.Black;
   
  //Apply font setting for cells with product details
  worksheet.Range["A3:E23"].CellStyle.Font.FontName = "Arial";
  worksheet.Range["A3:E23"].CellStyle.Font.Size = 10;
  worksheet.Range["A15:E15"].CellStyle.Font.Color = ExcelKnownColors.White;
  worksheet.Range["A15:E15"].CellStyle.Font.Bold = true;
  worksheet.Range["D23:E23"].CellStyle.Font.Bold = true;
   
  //Apply cell color
  worksheet.Range["A15:E15"].CellStyle.Color = ColorHelper.FromArgb(0, 42, 118, 189);
   
  //Apply alignment to cells with product details
  worksheet.Range["A15"].CellStyle.HorizontalAlignment = ExcelHAlign.HAlignLeft;
  worksheet.Range["C15:C22"].CellStyle.HorizontalAlignment = ExcelHAlign.HAlignCenter;
  worksheet.Range["D15:E15"].CellStyle.HorizontalAlignment = ExcelHAlign.HAlignCenter;
   
  //Apply row height and column width to look good
  worksheet.Range["A1"].ColumnWidth = 36;
  worksheet.Range["B1"].ColumnWidth = 11;
  worksheet.Range["C1"].ColumnWidth = 8;
  worksheet.Range["D1:E1"].ColumnWidth = 18;
  worksheet.Range["A1"].RowHeight = 47;
  worksheet.Range["A2"].RowHeight = 15;
  worksheet.Range["A3:A4"].RowHeight = 15;
  worksheet.Range["A5"].RowHeight = 18;
  worksheet.Range["A6"].RowHeight = 29;
  worksheet.Range["A7"].RowHeight = 18;
  worksheet.Range["A8"].RowHeight = 15;
  worksheet.Range["A9:A14"].RowHeight = 15;
  worksheet.Range["A15:A23"].RowHeight = 18;
   
  // Save the Workbook
  StorageFile storageFile;
  if (!(Windows.Foundation.Metadata.ApiInformation.IsTypePresent("Windows.Phone.UI.Input.HardwareButtons")))
  {
    FileSavePicker savePicker = new FileSavePicker();
    savePicker.SuggestedStartLocation = PickerLocationId.Desktop;
    savePicker.SuggestedFileName = "Output";
    savePicker.FileTypeChoices.Add("Excel Files", new List<string>() { ".xlsx" });
    storageFile = await savePicker.PickSaveFileAsync();
  }
  else
  {
    StorageFolder local = Windows.Storage.ApplicationData.Current.LocalFolder;
    storageFile = await local.CreateFileAsync("Output.xlsx", CreationCollisionOption.ReplaceExisting);
  }
  //Saving the workbook
  await workbook.SaveAsAsync(storageFile);
   
  // Launch the saved file
  await Windows.System.Launcher.LaunchFileAsync(storageFile);
}
    Private Sub OnButtonClicked(ByVal sender As Object, ByVal args As EventArgs)
'Create an instance of ExcelEngine
Using excelEngine As ExcelEngine = New ExcelEngine()
  Dim application As IApplication = excelEngine.Excel
  application.DefaultVersion = ExcelVersion.Xlsx
   
  'Create a workbook
  Dim workbook As IWorkbook = application.Workbooks.Create(1)
  Dim worksheet As IWorksheet = workbook.Worksheets(0)
   
  'Adding a picture
  Dim executingAssembly As Assembly = GetType(MainPage).GetTypeInfo().Assembly
  Dim inputStream As Stream = executingAssembly.GetManifestResourceStream("GettingStarted_UWP.AdventureCycles-Logo.png")
  Dim shape As IPictureShape = worksheet.Pictures.AddPicture(1, 1, inputStream, 20, 20)
   
  'Disable gridlines in the worksheet
  worksheet.IsGridLinesVisible = False
   
  'Enter values to the cells from A3 to A5
  worksheet.Range("A3").Text = "46036 Michigan Ave"
  worksheet.Range("A4").Text = "Canton, USA"
  worksheet.Range("A5").Text = "Phone: +1 231-231-2310"
   
  'Make the text bold
  worksheet.Range("A3:A5").CellStyle.Font.Bold = True
   
  'Merge cells
  worksheet.Range("D1:E1").Merge()
   
  'Enter text to the cell D1 and apply formatting.
  worksheet.Range("D1").Text = "INVOICE"
  worksheet.Range("D1").CellStyle.Font.Bold = True
  worksheet.Range("D1").CellStyle.Font.RGBColor = ColorHelper.FromArgb(0, 42, 118, 189)
  worksheet.Range("D1").CellStyle.Font.Size = 35
   
  'Apply alignment in the cell D1
  worksheet.Range("D1").CellStyle.HorizontalAlignment = ExcelHAlign.HAlignRight
  worksheet.Range("D1").CellStyle.VerticalAlignment = ExcelVAlign.VAlignTop
   
  'Enter values to the cells from D5 to E8
  worksheet.Range("D5").Text = "INVOICE#"
  worksheet.Range("E5").Text = "DATE"
  worksheet.Range("D6").Number = 1028
  worksheet.Range("E6").Value = "12/31/2018"
  worksheet.Range("D7").Text = "CUSTOMER ID"
  worksheet.Range("E7").Text = "TERMS"
  worksheet.Range("D8").Number = 564
  worksheet.Range("E8").Text = "Due Upon Receipt"
   
  'Apply RGB back color to the cells from D5 to E8
  worksheet.Range("D5:E5").CellStyle.Color = ColorHelper.FromArgb(0, 42, 118, 189)
  worksheet.Range("D7:E7").CellStyle.Color = ColorHelper.FromArgb(0,42, 118, 189)
   
  'Apply known colors to the text in cells D5 to E8
  worksheet.Range("D5:E5").CellStyle.Font.Color = ExcelKnownColors.White
  worksheet.Range("D7:E7").CellStyle.Font.Color = ExcelKnownColors.White
   
  'Make the text as bold from D5 to E8
  worksheet.Range("D5:E8").CellStyle.Font.Bold = True
   
  'Apply alignment to the cells from D5 to E8
  worksheet.Range("D5:E8").CellStyle.HorizontalAlignment = ExcelHAlign.HAlignCenter
  worksheet.Range("D5:E5").CellStyle.VerticalAlignment = ExcelVAlign.VAlignCenter
  worksheet.Range("D7:E7").CellStyle.VerticalAlignment = ExcelVAlign.VAlignCenter
  worksheet.Range("D6:E6").CellStyle.VerticalAlignment = ExcelVAlign.VAlignTop
   
  'Enter value and applying formatting in the cell A7
  worksheet.Range("A7").Text = "  BILL TO"
  worksheet.Range("A7").CellStyle.Color = ColorHelper.FromArgb(0, 42, 118, 189)
  worksheet.Range("A7").CellStyle.Font.Bold = True
  worksheet.Range("A7").CellStyle.Font.Color = ExcelKnownColors.White
   
  'Apply alignment
  worksheet.Range("A7").CellStyle.HorizontalAlignment = ExcelHAlign.HAlignLeft
  worksheet.Range("A7").CellStyle.VerticalAlignment = ExcelVAlign.VAlignCenter
   
  'Enter values in the cells A8 to A12
  worksheet.Range("A8").Text = "Steyn"
  worksheet.Range("A9").Text = "Great Lakes Food Market"
  worksheet.Range("A10").Text = "20 Whitehall Rd"
  worksheet.Range("A11").Text = "North Muskegon,USA"
  worksheet.Range("A12").Text = "+1 231-654-0000"
   
  'Create a Hyperlink for e-mail in the cell A13
  Dim hyperlink As IHyperLink = worksheet.HyperLinks.Add(worksheet.Range("A13"))
  hyperlink.Type = ExcelHyperLinkType.Url
  hyperlink.Address = "Steyn@greatlakes.com"
  hyperlink.ScreenTip = "Send Mail"
   
  'Merge column A and B from row 15 to 22
  worksheet.Range("A15:B15").Merge()
  worksheet.Range("A16:B16").Merge()
  worksheet.Range("A17:B17").Merge()
  worksheet.Range("A18:B18").Merge()
  worksheet.Range("A19:B19").Merge()
  worksheet.Range("A20:B20").Merge()
  worksheet.Range("A21:B21").Merge()
  worksheet.Range("A22:B22").Merge()
   
  'Enter details of products and prices
  worksheet.Range("A15").Text = "  DESCRIPTION"
  worksheet.Range("C15").Text = "QTY"
  worksheet.Range("D15").Text = "UNIT PRICE"
  worksheet.Range("E15").Text = "AMOUNT"
  worksheet.Range("A16").Text = "Cabrales Cheese"
  worksheet.Range("A17").Text = "Chocos"
  worksheet.Range("A18").Text = "Pasta"
  worksheet.Range("A19").Text = "Cereals"
  worksheet.Range("A20").Text = "Ice Cream"
  worksheet.Range("C16").Number = 3
  worksheet.Range("C17").Number = 2
  worksheet.Range("C18").Number = 1
  worksheet.Range("C19").Number = 4
  worksheet.Range("C20").Number = 3
  worksheet.Range("D16").Number = 21
  worksheet.Range("D17").Number = 54
  worksheet.Range("D18").Number = 10
  worksheet.Range("D19").Number = 20
  worksheet.Range("D20").Number = 30
  worksheet.Range("D23").Text = "Total"
   
  'Apply number format
  worksheet.Range("D16:E22").NumberFormat = "$.00"
  worksheet.Range("E23").NumberFormat = "$.00"
   
  'Apply incremental formula for column Amount by multiplying Qty and UnitPrice
  application.EnableIncrementalFormula = True
  worksheet.Range("E16:E20").Formula = "=C16*D16"
   
  'Formula for Sum the total
  worksheet.Range("E23").Formula = "=SUM(E16:E22)"
   
  'Apply borders
  worksheet.Range("A16:E22").CellStyle.Borders(ExcelBordersIndex.EdgeTop).LineStyle = ExcelLineStyle.Thin
  worksheet.Range("A16:E22").CellStyle.Borders(ExcelBordersIndex.EdgeBottom).LineStyle = ExcelLineStyle.Thin
  worksheet.Range("A16:E22").CellStyle.Borders(ExcelBordersIndex.EdgeTop).Color = ExcelKnownColors.Grey_25_percent
  worksheet.Range("A16:E22").CellStyle.Borders(ExcelBordersIndex.EdgeBottom).Color = ExcelKnownColors.Grey_25_percent
  worksheet.Range("A23:E23").CellStyle.Borders(ExcelBordersIndex.EdgeTop).LineStyle = ExcelLineStyle.Thin
  worksheet.Range("A23:E23").CellStyle.Borders(ExcelBordersIndex.EdgeBottom).LineStyle = ExcelLineStyle.Thin
  worksheet.Range("A23:E23").CellStyle.Borders(ExcelBordersIndex.EdgeTop).Color = ExcelKnownColors.Black
  worksheet.Range("A23:E23").CellStyle.Borders(ExcelBordersIndex.EdgeBottom).Color = ExcelKnownColors.Black
   
  'Apply font setting for cells with product details
  worksheet.Range("A3:E23").CellStyle.Font.FontName = "Arial"
  worksheet.Range("A3:E23").CellStyle.Font.Size = 10
  worksheet.Range("A15:E15").CellStyle.Font.Color = ExcelKnownColors.White
  worksheet.Range("A15:E15").CellStyle.Font.Bold = True
  worksheet.Range("D23:E23").CellStyle.Font.Bold = True
   
  'Apply cell color
  worksheet.Range("A15:E15").CellStyle.Color = ColorHelper.FromArgb(0, 42, 118, 189)
   
  'Apply alignment to cells with product details
  worksheet.Range("A15").CellStyle.HorizontalAlignment = ExcelHAlign.HAlignLeft
  worksheet.Range("C15:C22").CellStyle.HorizontalAlignment = ExcelHAlign.HAlignCenter
  worksheet.Range("D15:E15").CellStyle.HorizontalAlignment = ExcelHAlign.HAlignCenter
   
  'Apply row height and column width to look good
  worksheet.Range("A1").ColumnWidth = 36
  worksheet.Range("B1").ColumnWidth = 11
  worksheet.Range("C1").ColumnWidth = 8
  worksheet.Range("D1:E1").ColumnWidth = 18
  worksheet.Range("A1").RowHeight = 47
  worksheet.Range("A2").RowHeight = 15
  worksheet.Range("A3:A4").RowHeight = 15
  worksheet.Range("A5").RowHeight = 18
  worksheet.Range("A6").RowHeight = 29
  worksheet.Range("A7").RowHeight = 18
  worksheet.Range("A8").RowHeight = 15
  worksheet.Range("A9:A14").RowHeight = 15
  worksheet.Range("A15:A23").RowHeight = 18
   
  'Save the Workbook
  Dim storageFile As StorageFile
  If Not Windows.Foundation.Metadata.ApiInformation.IsTypePresent("Windows.Phone.UI.Input.HardwareButtons") Then
    Dim savePicker As FileSavePicker = New FileSavePicker
    savePicker.SuggestedStartLocation = PickerLocationId.Desktop
    savePicker.SuggestedFileName = "Output"
    savePicker.FileTypeChoices.Add("Excel Files", New List(Of String))
    storageFile = savePicker.PickSaveFileAsync
  Else
    Dim local As StorageFolder = Windows.Storage.ApplicationData.Current.LocalFolder
    storageFile = local.CreateFileAsync("Output.xlsx", CreationCollisionOption.ReplaceExisting)
  End If
   
  'Saving the workbook
  Function workbook_SaveAsAsync_((ByVal Unknown As storageFile) As await Implements workbook.SaveAsAsync.(Of
  End Function
   
  'Launch the saved file
  Function Windows_System_Launcher_LaunchFileAsync_((ByVal Unknown As storageFile) As await Implements Windows.System.Launcher.LaunchFileAsync.(Of
  End Function
End Using

A complete working example of how to create an Excel file in UWP in C# is present on this GitHub page.

By executing the program, you will get the Excel file as below.
Output File
Output File

Read and Edit Excel file

The below code illustrates how to read and edit an Excel file in UWP.

//Create an instance of ExcelEngine
ExcelEngine excelEngine = new ExcelEngine();
IApplication application = excelEngine.Excel;

//Instantiates the File Picker. 
FileOpenPicker openPicker = new FileOpenPicker();
openPicker.SuggestedStartLocation = PickerLocationId.Desktop;
openPicker.FileTypeFilter.Add(".xlsx");
openPicker.FileTypeFilter.Add(".xls");
StorageFile openFile = await openPicker.PickSingleFileAsync();

//Opens the workbook. 
IWorkbook workbook = await application.Workbooks.OpenAsync(openFile);

//Access first worksheet from the workbook.
IWorksheet worksheet = workbook.Worksheets[0];

//Set Text in cell A3.
worksheet.Range["A3"].Text ="Hello World";

//Access a cell value from Excel
var value = worksheet.Range["A1"].Value;

//Sets workbook version.
workbook.Version = ExcelVersion.Xlsx;

//Initializes FileSavePicker.
FileSavePicker savePicker = new FileSavePicker();
savePicker.SuggestedStartLocation = PickerLocationId.Desktop;
savePicker.SuggestedFileName = "CreateSpreadsheet";
savePicker.FileTypeChoices.Add("Excel Files", new List<string>() { ".xlsx" });

//Creates a storage file from FileSavePicker.
StorageFile storageFile = await savePicker.PickSaveFileAsync();

//Saves changes to the specified storage file.
await workbook.SaveAsAsync(storageFile);

workbook.Close();
excelEngine.Dispose();
'Create an instance of ExcelEngine
Dim excelEngine As ExcelEngine = New ExcelEngine()
Dim application As IApplication = excelEngine.Excel

'Instantiates the File Save Picker.  
Dim openPicker As New FileOpenPicker()
openPicker.SuggestedStartLocation = PickerLocationId.Desktop 
openPicker.FileTypeFilter.Add(".xlsx") 
openPicker.FileTypeFilter.Add(".xls") 
Dim openFile As StorageFile = Await openPicker.PickSingleFileAsync()

'Opens the Workbook. 
Dim workbook As IWorkbook = Await application.Workbooks.OpenAsync(openFile)
Dim workbook.SaveAsAsyncCType(As await, openFile)

'Access first worksheet from the workbook.
Dim worksheet As IWorksheet = workbook.Worksheets(0)

'Set Text in cell A3.
worksheet.Range("A3").Text ="Hello World"

'Access a cell value from Excel
Dim value As var = worksheet.Range("A1").Value

'Sets workbook version.
workbook.Version = ExcelVersion.Xlsx

'Initializes FileSavePicker.
Dim savePicker As New FileSavePicker()
savePicker.SuggestedStartLocation = PickerLocationId.Desktop
savePicker.SuggestedFileName = "CreateSpreadsheet"
savePicker.FileTypeChoices.Add("Excel Files", New List(Of String)() From {".xlsx"})

'Creates a storage file from FileSavePicker.
Dim storageFile As StorageFile = Await savePicker.PickSaveFileAsync()

'Saves changes to the specified storage file.
Await workbook.SaveAsAsync(storageFile)

workbook.Close()
excelEngine.Dispose()

A complete working example of how to read and edit an Excel file in UWP in C# is present on this GitHub page.

NOTE

Starting with v16.2.0.x, if you reference Syncfusion assemblies from trial setup or from the NuGet feed, you also have to add “Syncfusion.Licensing” assembly reference and include a license key in your projects. Please refer to this link to know about registering Syncfusion license key in your applications to use our components. You can also explore our UWP Excel library demo that shows how to create and modify Excel files from C# with just five lines of code.