In this article I will explain with an example, how to upload, read (import) and display Excel file (sheet) data using OpenXml in ASP.Net with C# and VB.Net.
 
 

Install DocumentFormat.OpenXml package

In order to install DocumentFormat.OpenXml library using Nuget, please refer my article Install DocumentFormat.OpenXml Nuget Package.
 
 

HTML Markup

The HTML Markup consists of following controls:
FileUpload – For selecting file.
Button – For importing the selected file.
The Button has been assigned with an OnClick event handler.
 
GridView – For displaying data.

Columns

The GridView consists of three BoundField columns.
<asp:FileUpload ID="fuUpload" runat="server" /> 
<asp:Button ID="btnImport" runat="server" Text="Import" OnClick="OnImportExcel" /> 
<hr />
<asp:GridView ID="gvCustomers" runat="server" AutoGenerateColumns="false"> 
    <Columns>
        <asp:BoundField DataField="CustomerId" HeaderText="Customer Id" /> 
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
    </Columns>
</asp:GridView>
 
 

Namespaces

You will need to import the following namespaces.
C#
using System.IO;
using System.Data;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml.Spreadsheet;
 
VB.Net
Imports System.IO
Imports System.Data
Imports DocumentFormat.OpenXml.Packaging
Imports DocumentFormat.OpenXml.Spreadsheet
 
 

Reading and Importing Excel file using OpenXml in ASP.Net

Importing the Excel file

When the Import Button is clicked, first the uploaded Excel file is saved to a Directory (Folder) named Files and the file name is determined using GetFileName method of the Path class.
After that, the instance of the first Sheet is determined and all the rows present in the Sheet are fetched.
Then, a nested FOR EACH loop is executed over the fetched rows and GetValue method (explained later) is called and columns are defined and data of the Excel file is added to the DataTable.
Finally, the DataTable is assigned to the DataSource property of the GridView and the GridView is populated.
 

GetValue

The GetValue method accepts SpreadsheetDocument and Cell class objects as a parameter where a cell value is determined and initialized.
Then, a check is performed if cell datatype NOT equal to NULL and cell value is string then, it returns the cell value.
C#
protected void OnImportExcel(object sender, EventArgs e)
{
    //Save the uploaded Excel file.
    string filePath = Server.MapPath("~/Files/") + Path.GetFileName(fuUpload.PostedFile.FileName);
    fuUpload.SaveAs(filePath);
 
    //Create a new DataTable.
    DataTable dt = new DataTable();
 
    //Open the Excel file in Read Mode using OpenXml.
    using (SpreadsheetDocument doc = SpreadsheetDocument.Open(filePath, false))
    {
        //Read the first Sheets from Excel file.
        Sheet sheet = doc.WorkbookPart.Workbook.Sheets.GetFirstChild<Sheet>();
 
        //Get the Worksheet instance.
        Worksheet worksheet = (doc.WorkbookPart.GetPartById(sheet.Id.Value) as WorksheetPart).Worksheet;
 
        //Fetch all the rows present in the Worksheet.
        IEnumerable<Row> rows = worksheet.GetFirstChild<SheetData>().Descendants<Row>();
 
        //Loop through the Worksheet rows.
        foreach (Row row in rows)
        {
            //Use the first row to add columns to DataTable
            if (row.RowIndex.Value == 1)
            {
                foreach (Cell cell in row.Descendants<Cell>())
                {
                    dt.Columns.Add(this.GetValue(doc, cell));
                }
            }
            else
            {
                //Add rows to DataTable.
                dt.Rows.Add();
                int i = 0;
                foreach (Cell cell in row.Descendants<Cell>())
                {
                    dt.Rows[dt.Rows.Count - 1][i] = this.GetValue(doc, cell);
                    i++;
                }
            }
        }
    }
 
    gvCustomers.DataSource = dt;
    gvCustomers.DataBind();
}
 
private string GetValue(SpreadsheetDocument doc, Cell cell)
{
    string value = cell.CellValue.InnerText;
    if (cell.DataType != null && cell.DataType.Value == CellValues.SharedString)
    {
        return doc.WorkbookPart.SharedStringTablePart.SharedStringTable.ChildElements.GetItem(int.Parse(value)).InnerText;
    }
    return value;
}
 
VB.Net
Protected Sub OnImportExcel(sender As Object, e As EventArgs)
    'Save the uploaded Excel file.
    Dim filePath As String = Server.MapPath("~/Files/") + Path.GetFileName(fuUpload.PostedFile.FileName)
    fuUpload.SaveAs(filePath)
 
    'Open the Excel file in Read Mode using OpenXml.
    Using doc As SpreadsheetDocument = SpreadsheetDocument.Open(filePath, False)
        'Read the first Sheets from Excel file.
        Dim sheet As Sheet = doc.WorkbookPart.Workbook.Sheets.GetFirstChild(Of Sheet)()
 
        'Get the Worksheet instance.
        Dim worksheet As Worksheet = TryCast(doc.WorkbookPart.GetPartById(sheet.Id.Value), WorksheetPart).Worksheet
 
        'Fetch all the rows present in the Worksheet.
        Dim rows As IEnumerable(Of Row) = worksheet.GetFirstChild(Of SheetData)().Descendants(Of Row)()
 
        'Create a new DataTable.
        Dim dt As New DataTable()
 
        'Loop through the Worksheet rows.
        For Each Row As Row In rows
            'Use the first row to add columns to DataTable
            If Row.RowIndex.Value = 1Then
                For Each Cell As Cell In Row.Descendants(Of Cell)()
                    dt.Columns.Add(Me.GetValue(doc, Cell))
                Next
            Else
                'Add rows to DataTable.
                dt.Rows.Add()
                Dim i As Integer = 0
                For Each cell As Cell In Row.Descendants(Of Cell)()
                    dt.Rows(dt.Rows.Count - 1)(i) = Me.GetValue(doc, cell)
                    i += 1
                Next
            End If
        Next
 
        gvCustomers.DataSource = dt
        gvCustomers.DataBind()
    End Using
End Sub
 
Private Function GetValue(doc As SpreadsheetDocument, cell As Cell) As String
    Dim value As String = cell.CellValue.InnerText
    If cell.DataType IsNot Nothing AndAlso cell.DataType.Value = CellValues.SharedString Then
        Return doc.WorkbookPart.SharedStringTablePart.SharedStringTable.ChildElements.GetItem(Integer.Parse(value)).InnerText
    End If
    Return value
End Function
 
 

Screenshots

The Excel File

Upload, Read and Display Excel file data using OpenXml in ASP.Net
 

Grid displaying Excel data

Upload, Read and Display Excel file data using OpenXml in ASP.Net
 
 

Downloads

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