How to Read Excel File in Blazor NET

Name: IronXL
Brand: Iron Software
Availability: InStock
Rating: 4.67 (175 reviews)

ByRegan Pun

April 17, 2025

Updated June 2, 2025

In this tutorial, you will learn how to view Excel files within a Blazor Server application by setting up an Excel file viewer using IronXL. The process involves integrating IronXL into a Visual Studio project and working with the necessary code.

First, import the required using statements for IronXL and System.Data. Define a table structure in HTML with dynamic headers based on the Excel file's columns, while the rows are filled with data from the file.

In the @code section, a data table named displayDataTable is declared to store Excel data. The OpenExcelFromDisk method manages file uploads and data extraction. When an Excel file is uploaded, it is read into a memory stream, which IronXL loads into a workbook object. The first row's headers become the data table's columns, and subsequent rows are added as data rows.

Running the code opens a Blazor web application page where you can navigate to the 'fetch data' menu, open an Excel file, and view its contents. This tutorial demonstrates the simplicity of using IronXL to create an Excel file viewer in a Blazor server app, enhancing web application capabilities.

@page "/fetchdata"

@using System.Data
@using IronXL

@* HTML Table to display Excel data *@
<table>
    <thead>
        <tr>
            @* Table headers are generated dynamically *@
            @foreach (DataColumn column in displayDataTable.Columns)
            {
                <th>@column.ColumnName</th>
            }
        </tr>
    </thead>
    <tbody>
        @* Table rows are generated dynamically *@
        @foreach (DataRow row in displayDataTable.Rows)
        {
            <tr>
                @foreach (var item in row.ItemArray)
                {
                    <td>@item</td>
                }
            </tr>
        }
    </tbody>
</table>

@code {
    // DataTable to hold the data extracted from Excel
    private DataTable displayDataTable = new DataTable();

    /// <summary>
    /// Method to open Excel file from disk and extract data
    /// </summary>
    /// <param name="filePath">Path to the Excel file</param>
    private void OpenExcelFromDisk(string filePath)
    {
        // Load the Excel file into a WorkBook
        var workbook = WorkBook.Load(filePath);

        // Get the first worksheet
        var sheet = workbook.WorkSheets[0];

        // Initialize DataTable columns from the first row
        foreach (var column in sheet[0])
        {
            displayDataTable.Columns.Add(column.ToString());
        }

        // Append DataTable rows from subsequent rows in the Excel sheet
        for (int i = 1; i < sheet.RowCount; i++)
        {
            DataRow newRow = displayDataTable.NewRow();
            for (int j = 0; j < sheet.ColumnCount; j++)
            {
                newRow[j] = sheet[i][j].ToString();
            }
            displayDataTable.Rows.Add(newRow);
        }
    }
}

@page "/fetchdata"

@using System.Data
@using IronXL

@* HTML Table to display Excel data *@
<table>
    <thead>
        <tr>
            @* Table headers are generated dynamically *@
            @foreach (DataColumn column in displayDataTable.Columns)
            {
                <th>@column.ColumnName</th>
            }
        </tr>
    </thead>
    <tbody>
        @* Table rows are generated dynamically *@
        @foreach (DataRow row in displayDataTable.Rows)
        {
            <tr>
                @foreach (var item in row.ItemArray)
                {
                    <td>@item</td>
                }
            </tr>
        }
    </tbody>
</table>

@code {
    // DataTable to hold the data extracted from Excel
    private DataTable displayDataTable = new DataTable();

    /// <summary>
    /// Method to open Excel file from disk and extract data
    /// </summary>
    /// <param name="filePath">Path to the Excel file</param>
    private void OpenExcelFromDisk(string filePath)
    {
        // Load the Excel file into a WorkBook
        var workbook = WorkBook.Load(filePath);

        // Get the first worksheet
        var sheet = workbook.WorkSheets[0];

        // Initialize DataTable columns from the first row
        foreach (var column in sheet[0])
        {
            displayDataTable.Columns.Add(column.ToString());
        }

        // Append DataTable rows from subsequent rows in the Excel sheet
        for (int i = 1; i < sheet.RowCount; i++)
        {
            DataRow newRow = displayDataTable.NewRow();
            for (int j = 0; j < sheet.ColumnCount; j++)
            {
                newRow[j] = sheet[i][j].ToString();
            }
            displayDataTable.Rows.Add(newRow);
        }
    }
}

page "/fetchdata" [using] System.Data [using] IronXL * HTML Table [to] display Excel data * (Of thead) (Of tr) * Table headers are generated dynamically *[Function]n foreach(DataColumn column ByVal displayDataTable.Columns As in) As (Of table)
				(Of th) column.ColumnName</th>
End Function
		</tr> </thead> * Table rows are generated dynamically *[Function]n foreach(DataRow row ByVal displayDataTable.Rows As in) As (Of tbody)
'INSTANT VB TODO TASK: Local functions are not converted by Instant VB:
'			(Of tr) @foreach(var item in row.ItemArray)
'				{
'					<td> @item</td>
'				}
			</tr>
		End Function
'INSTANT VB TODO TASK: The following line could not be converted:
	</tbody> </table> code
	If True Then
	' DataTable to hold the data extracted from Excel
	private DataTable displayDataTable = New DataTable()

	''' <summary>
	''' Method to open Excel file from disk and extract data
	''' </summary>
	''' <param name="filePath">Path to the Excel file</param>
'INSTANT VB TODO TASK: Local functions are not converted by Instant VB:
'	private void OpenExcelFromDisk(string filePath)
'	{
'		' Load the Excel file into a WorkBook
'		var workbook = WorkBook.Load(filePath);
'
'		' Get the first worksheet
'		var sheet = workbook.WorkSheets[0];
'
'		' Initialize DataTable columns from the first row
'		foreach (var column in sheet[0])
'		{
'			displayDataTable.Columns.Add(column.ToString());
'		}
'
'		' Append DataTable rows from subsequent rows in the Excel sheet
'		for (int i = 1; i < sheet.RowCount; i++)
'		{
'			DataRow newRow = displayDataTable.NewRow();
'			for (int j = 0; j < sheet.ColumnCount; j++)
'			{
'				newRow[j] = sheet[i][j].ToString();
'			}
'			displayDataTable.Rows.Add(newRow);
'		}
'	}
	End If

$vbLabelText $csharpLabel

Further Reading: Blazor Read Excel File in C# Using IronXL (Example Tutorial)

Regan Pun

Chat with engineering team now

Software Engineer

Regan graduated from the University of Reading, with a BA in Electronic Engineering. Before joining Iron Software, his previous job roles had him laser-focused on single tasks; and what he most enjoys at Iron Software is the spectrum of work he gets to undertake, whether it’s adding value to sales, technical support, product development or marketing. He enjoys understanding the way developers are using the Iron Software library, and using that knowledge to continually improve documentation and develop the products.

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