Exporting ASP.Net GridView to Excel file is blank using C# and VB.Net

Hi BugHunter,

You are not adding Worksheets to XLWorkbook. Before writing the MemoryStream you need to add Worksheets to XLWorkbook.

Refer below example.

Database

For this example I have used of Northwind database that you can download using the link given below.

Download Northwind Database

HTML

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="CustomerID" HeaderText="Customer ID" HtmlEncode="false" />
        <asp:BoundField DataField="ContactName" HeaderText="Contact Name" HtmlEncode="false" />
        <asp:BoundField DataField="City" HeaderText="City" HtmlEncode="false" />
        <asp:BoundField DataField="Country" HeaderText="Country" HtmlEncode="false" />
    </Columns>
</asp:GridView>
<br />
<asp:Button ID="btnExport" Text="Export" OnClick="ExportExcel" runat="server" />

Namespaces

C#

using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.IO;
using System.Web.UI.WebControls;
using ClosedXML.Excel;

VB.Net

Imports System.Data
Imports System.Data.SqlClient
Imports System.IO
Imports ClosedXML.Excel

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGrid();
    }
}

private void BindGrid()
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT CustomerId, ContactName, City, Country FROM Customers"))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                cmd.Connection = con;
                sda.SelectCommand = cmd;
                using (DataTable dt = new DataTable())
                {
                    sda.Fill(dt);
                    GridView1.DataSource = dt;
                    GridView1.DataBind();
                }
            }
        }
    }
}

protected void ExportExcel(object sender, EventArgs e)
{
    DataTable dt = new DataTable("GridView_Data");
    foreach (TableCell cell in GridView1.HeaderRow.Cells)
    {
        dt.Columns.Add(cell.Text);
    }
    foreach (GridViewRow row in GridView1.Rows)
    {
        dt.Rows.Add();
        for (int i = 0; i < row.Cells.Count; i++)
        {
            dt.Rows[dt.Rows.Count - 1][i] = row.Cells[i].Text;
        }
    }
    using (XLWorkbook wb = new XLWorkbook())
    {
        wb.Worksheets.Add(dt);
        Response.Clear();
        Response.Buffer = true;
        Response.Charset = "";
        Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
        Response.AddHeader("content-disposition", "attachment;filename=GridView.xlsx");
        using (MemoryStream MyMemoryStream = new MemoryStream())
        {
            wb.SaveAs(MyMemoryStream);
            MyMemoryStream.WriteTo(Response.OutputStream);
            Response.Flush();
            Response.End();
        }
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.BindGrid()
    End If
End Sub

Private Sub BindGrid()
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(constr)
        Using cmd As SqlCommand = New SqlCommand("SELECT CustomerId, ContactName, City, Country FROM Customers")
            Using sda As SqlDataAdapter = New SqlDataAdapter()
                cmd.Connection = con
                sda.SelectCommand = cmd
                Using dt As DataTable = New DataTable()
                    sda.Fill(dt)
                    GridView1.DataSource = dt
                    GridView1.DataBind()
                End Using
            End Using
        End Using
    End Using
End Sub

Protected Sub ExportExcel(ByVal sender As Object, ByVal e As EventArgs)
    Dim dt As DataTable = New DataTable("GridView_Data")
    For Each cell As TableCell In GridView1.HeaderRow.Cells
        dt.Columns.Add(cell.Text)
    Next
    For Each row As GridViewRow In GridView1.Rows
        dt.Rows.Add()
        For i As Integer = 0 To row.Cells.Count - 1
            dt.Rows(dt.Rows.Count - 1)(i) = row.Cells(i).Text
        Next
    Next
    Using wb As XLWorkbook = New XLWorkbook()
        wb.Worksheets.Add(dt)
        Response.Clear()
        Response.Buffer = True
        Response.Charset = ""
        Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
        Response.AddHeader("content-disposition", "attachment;filename=GridView.xlsx")
        Using MyMemoryStream As MemoryStream = New MemoryStream()
            wb.SaveAs(MyMemoryStream)
            MyMemoryStream.WriteTo(Response.OutputStream)
            Response.Flush()
            Response.End()
        End Using
    End Using
End Sub

Screenshot

Excel after Export