Create, read, and edit Excel files in Blazor

10 Oct 202224 minutes to read

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

Create a simple Excel report in Blazor Server-Side application

The below steps illustrates the creation of a simple Invoice formatted Excel document in Blazor Server-Side application.

  1. Create a new C# Blazor Server-Side application project. Select Blazor App from the template and click the Next button.

Create Blazor Server Side application in Visual Studio

  1. Now, the project configuration window will popup. Click Create button to create a new project with the required project name.

Create Blazor Server Side application in Visual Studio

  1. Choose Blazor Server App and click Create button to create a new Blazor Server-Side application for .NET Core 3.0.0-preview9.

Create Blazor Server Side application in Visual Studio

  1. Install the Syncfusion.XlsIO.Net.Core NuGet package as reference to your Blazor application from NuGet.org.

Add XlsIO reference to the project

  1. Create a razor file with name as Excel under Pages folder and include the following namespaces in the file.

    @page "/Excel"
    @using System.IO;
    @using ServerSideApplication;
    @inject ServerSideApplication.Data.ExcelService service
    @inject Microsoft.JSInterop.IJSRuntime JS
  2. Add the following code to create a new button.

    <h2>Syncfusion Excel library (Essential XlsIO)</h2>
    <p>Syncfusion Excel library (Essential XlsIO)  is a Blazor Excel library used to create, read, edit, and convert Excel files in your applications without Microsoft Office dependencies.</p>
    <button class="btn btn-primary" @onclick="@CreateDocument">Create Document</button>
  3. Add the following code in Excel.razor file to create and download the Excel document.

    @code {
        MemoryStream excelStream;
       
        /// <summary>
        /// Create and download the Excel document
        /// </summary>
        protected async void CreateDocument()
        {
            excelStream = service.CreateExcel();
            await JS.SaveAs("Sample.xlsx", excelStream.ToArray());
        }
    }
  4. Create a new cs file with name as ExcelService under Data folder and include the following namespaces in the file.

    @using Syncfusion.XlsIO;
    @using Syncfusion.Drawing;
    @using System.IO;
  5. Create a new MemoryStream method with name as CreateExcel and include the following code snippet to create a simple Invoice formatted Excel document in Blazor Server-Side application.

    //Create an instance of ExcelEngine
    using (ExcelEngine excelEngine = new ExcelEngine())
    {
        IApplication application = excelEngine.Excel;
        application.DefaultVersion = ExcelVersion.Xlsx;
       
        //Create a workbook
        IWorkbook workbook = application.Workbooks.Create(1);
        IWorksheet worksheet = workbook.Worksheets[0];
       
        //Add a picture
        FileStream imageStream = new FileStream("AdventureCycle.png", FileMode.Open);
        Image image = Image.FromStream(imageStream);
        IPictureShape shape = worksheet.Pictures.AddPicture(1, 1, image, 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 = Color.FromArgb(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 = Color.FromArgb(42, 118, 189);
        worksheet.Range["D7:E7"].CellStyle.Color = Color.FromArgb(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 = Color.FromArgb(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";
       
        //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 = Color.FromArgb(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 document as a stream and retrun the stream.
        using (MemoryStream stream = new MemoryStream())
        {
            //Save the created Excel document to MemoryStream
            workbook.SaveAs(stream);
            return stream;
        }
    }
  6. Create a new class file in the project, with name as FileUtils and add the following code to invoke the JavaScript action for downloading the file in browser.

public static class FileUtils
   {
       public static ValueTask<object> SaveAs(this IJSRuntime js, string filename, byte[] data)
           => js.InvokeAsync<object>(
              "saveAsFile",
              filename,
              Convert.ToBase64String(data));
   }
  1. Add the following JavaScript function in the _Host.cshtml file present under Pages folder.
<script type="text/javascript">
       function saveAsFile(filename, bytesBase64) {
   
       if (navigator.msSaveBlob) 
   	{
           //Download document in Edge browser
           var data = window.atob(bytesBase64);
           var bytes = new Uint8Array(data.length);
           for (var i = 0; i < data.length; i++) 
   		{
               bytes[i] = data.charCodeAt(i);
           }
           var blob = new Blob([bytes.buffer], { type: "application/octet-stream" });
           navigator.msSaveBlob(blob, filename);
       }
       else 
   	{
           var link = document.createElement('a');
           link.download = filename;
           link.href = "data:application/octet-stream;base64," + bytesBase64;
           document.body.appendChild(link); // Needed for Firefox
           link.click();
           document.body.removeChild(link);
       }
   }
   </script>

A complete working example of how to create an Excel file in Blazor Server-Side application in C# is present on this GitHub page.

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

NOTE

It is recommended to use Blazor Server-Side application to reduce the pay back load which is high in Blazor Client-Side.

Read and Edit Excel file in Blazor Server-Side application

The below code snippet illustrates how to read and edit an Excel file in Blazor Server-Side application.

//Create an instance of ExcelEngine
using (ExcelEngine excelEngine = new ExcelEngine())
{
    //Instantiate the Excel application object
    IApplication application = excelEngine.Excel;

    //Set the default application version
    application.DefaultVersion = ExcelVersion.Xlsx;

    //Load the existing Excel workbook into IWorkbook
    FileStream inputStream = new FileStream("Sample.xlsx", FileMode.Open);
    IWorkbook workbook = application.Workbooks.Open(inputStream);

    //Get the first worksheet in the workbook into IWorksheet
    IWorksheet worksheet = workbook.Worksheets[0];

    //Assign some text in a cell
    worksheet.Range["A3"].Text = "Hello World";

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

    //Save the document as a stream and retrun the stream.
    using (MemoryStream stream = new MemoryStream())
    {
        //Save the created Excel document to MemoryStream.
        workbook.SaveAs(stream);

        return stream;
    }
}

A complete working example of how to read and edit an Excel file in Blazor Server-Side application in C# is present on this GitHub page.

Create a simple Excel report in Blazor Client-Side application

The below steps illustrates the creation of a simple Invoice formatted Excel document in Blazor Client-Side application.

  1. Create a new C# Blazor Client-Side application project. Select Blazor App from the template and click the Next button.

Create Blazor Server Side application in Visual Studio

  1. Now, the project configuration window will popup. Click Create button to create a new project with the required project name.

Create Blazor Server Side application in Visual Studio

  1. Choose Blazor WebAssembly App and click Create button to create a new Blazor Client-Side application for .NET Core 3.0.0-preview9.

Create Blazor Server Side application in Visual Studio

  1. Install the Syncfusion.XlsIO.Net.Core NuGet package as reference to your Blazor application from NuGet.org.

Add XlsIO reference to the project

  1. Create a razor file with name as Excel under Pages folder and add the following namespaces in the file.

    @page "/Excel"
    @using Syncfusion.XlsIO;
    @using Syncfusion.Drawing;
    @using System.IO;
    @inject Microsoft.JSInterop.IJSRuntime JS
  2. Add the following code to create a new button.

    <h2>Syncfusion Excel library (Essential XlsIO)</h2>
    <p>Syncfusion Excel library (Essential XlsIO)  is a Blazor Excel library used to create, read, edit, and convert Excel files in your applications without Microsoft Office dependencies.</p>
    <button class="btn btn-primary" @onclick="@CreateDocument">Create Document</button>
  3. Create a new async method with name as CreateDocument and include the following code snippet to create a simple Invoice formatted Excel document in Blazor Client-Side application.

    //Create an instance of ExcelEngine
    using (ExcelEngine excelEngine = new ExcelEngine())
    {
        IApplication application = excelEngine.Excel;
        application.DefaultVersion = ExcelVersion.Xlsx;
       
        //Create a workbook
        IWorkbook workbook = application.Workbooks.Create(1);
        IWorksheet worksheet = workbook.Worksheets[0];
       
        //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 B1 and apply formatting
        worksheet.Range["B1"].Text = "INVOICE";
        worksheet.Range["B1"].CellStyle.Font.Bold = true;
        worksheet.Range["B1"].CellStyle.Font.RGBColor = Color.FromArgb(42, 118, 189);
        worksheet.Range["B1"].CellStyle.Font.Size = 35;
       
        //Apply alignment in the cell B1
        worksheet.Range["B1"].CellStyle.HorizontalAlignment = ExcelHAlign.HAlignCenter;
        worksheet.Range["B1"].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 = Color.FromArgb(42, 118, 189);
        worksheet.Range["D7:E7"].CellStyle.Color = Color.FromArgb(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 = Color.FromArgb(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";
       
        //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 = Color.FromArgb(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 document as a stream and retrun the stream.
        using (MemoryStream stream = new MemoryStream())
        {
            //Save the created Excel document to MemoryStream
            workbook.SaveAs(stream);
       		
            //Download the excel file
            await JS.SaveAs("Sample.xlsx", stream.ToArray());
        }
    }
  4. Create a class file with name as FileUtils and add the following code to invoke the JavaScript action for downloading the file in browser.

    public static class FileUtils
    {
        public static ValueTask<object> SaveAs(this IJSRuntime js, string filename, byte[] data)
            => js.InvokeAsync<object>(
               "saveAsFile",
               filename,
               Convert.ToBase64String(data));
    }
  5. Add the following JavaScript function in the index.html file present under wwwroot.

    <script type="text/javascript">
        function saveAsFile(filename, bytesBase64) {
       
        if (navigator.msSaveBlob) 
    	{
            //Download document in Edge browser
            var data = window.atob(bytesBase64);
            var bytes = new Uint8Array(data.length);
            for (var i = 0; i < data.length; i++) 
    		{
                bytes[i] = data.charCodeAt(i);
            }
            var blob = new Blob([bytes.buffer], { type: "application/octet-stream" });
            navigator.msSaveBlob(blob, filename);
        }
        else 
    	{
            var link = document.createElement('a');
            link.download = filename;
            link.href = "data:application/octet-stream;base64," + bytesBase64;
            document.body.appendChild(link); // Needed for Firefox
            link.click();
            document.body.removeChild(link);
        }
    }
    </script>

A complete working example of how to create an Excel file in Blazor Client-Side Application in C# is present on this GitHub page.

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

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 Blazor Excel library demo that shows how to create and modify Excel files from C# with just five lines of code.