Download files from GridView using LinkButton Click Event in ASP.Net using C# and VB.Net.

HTML Markup

Below is the HTML Markup of the page, where I have an ASP.Net control FileUpload to upload files, a Buttoncontrol to trigger file uploads and an ASP.Net GridViewcontrol to display the files from folder.

<asp:FileUpload ID="FileUpload1" runat="server" />

<asp:Button ID="btnUpload" runat="server" Text="Upload" OnClick="UploadFile" />

<hr />

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" EmptyDataText = "No files uploaded">

    <Columns>

        <asp:BoundField DataField="Text" HeaderText="File Name" />

        <asp:TemplateField>

            <ItemTemplate>

                <asp:LinkButton ID="lnkDownload" Text = "Download" CommandArgument = '<%# Eval("Value") %>' runat="server" OnClick = "DownloadFile"></asp:LinkButton>

            </ItemTemplate>

        </asp:TemplateField>

        <asp:TemplateField>

            <ItemTemplate>

                <asp:LinkButton ID = "lnkDelete" Text = "Delete" CommandArgument = '<%# Eval("Value") %>' runat = "server" OnClick = "DeleteFile" />

            </ItemTemplate>

        </asp:TemplateField>

    </Columns>

</asp:GridView>

Namespaces

You will need to import the following namespaces.

C#

using System.IO;

VB.Net

Imports System.IO

Uploading the File and saving in directory or folder

When the file is selected in APS.Net FileUpload control and the Upload button is clicked the following event handler is triggered. Below I have folder Uploads in the root directory of my ASP.Net Website where I am saving the uploaded file.

C#

protected void UploadFile(object sender, EventArgs e)

{

    string fileName = Path.GetFileName(FileUpload1.PostedFile.FileName);

    FileUpload1.PostedFile.SaveAs(Server.MapPath("~/Uploads/") + fileName);

    Response.Redirect(Request.Url.AbsoluteUri);

}

VB.Net

Protected Sub UploadFile(ByVal sender As Object, ByVal e As EventArgs)

    Dim fileName As String = Path.GetFileName(FileUpload1.PostedFile.FileName)

    FileUpload1.PostedFile.SaveAs((Server.MapPath("~/Uploads/") + fileName))

    Response.Redirect(Request.Url.AbsoluteUri)

End Sub

Displaying the files from folder or directory in ASP.Net GridView

Here I am reading all the files from the Uploads directory which I have created and then binding the fetched files to the ASP.Net GridView control.

C#

protected void Page_Load(object sender, EventArgs e)

{

    if (!IsPostBack)

    {

        string[] filePaths = Directory.GetFiles(Server.MapPath("~/Uploads/"));

        List<ListItem> files = new List<ListItem>();

        foreach (string filePath in filePaths)

        {

            files.Add(new ListItem(Path.GetFileName(filePath), filePath));

        }

        GridView1.DataSource = files;

        GridView1.DataBind();

    }

}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load

    If Not IsPostBack Then

        Dim filePaths() As String = Directory.GetFiles(Server.MapPath("~/Uploads/"))

        Dim files As List(Of ListItem) = New List(Of ListItem)

        For Each filePath As String In filePaths

            files.Add(New ListItem(Path.GetFileName(filePath), filePath))

        Next

        GridView1.DataSource = files

        GridView1.DataBind()

    End If

End Sub

Downloading the Uploaded File from ASP.Net GridView

The following event handler is executed when the lnkDownload LinkButton is clicked in the ASP.Net GridView Row. Using the CommandArgument property of the ASP.Net LinkButton, I get the path of the file using which I am downloading the file.

C#

protected void DownloadFile(object sender, EventArgs e)

{

    string filePath = (sender as LinkButton).CommandArgument;

    Response.ContentType = ContentType;

    Response.AppendHeader("Content-Disposition", "attachment; filename=" + Path.GetFileName(filePath));

    Response.WriteFile(filePath);

    Response.End();

}

VB.Net

Protected Sub DownloadFile(ByVal sender As Object, ByVal e As EventArgs)

    Dim filePath As String = CType(sender, LinkButton).CommandArgument

    Response.ContentType = ContentType

    Response.AppendHeader("Content-Disposition", ("attachment; filename=" + Path.GetFileName(filePath)))

    Response.WriteFile(filePath)

    Response.End()

End Sub

Deleting the Uploaded File from ASP.Net GridView

The following event handler is executed when the lnkDelete LinkButton is clicked in the ASP.Net GridView Row. Using the CommandArgument property of the ASP.Net LinkButton, I get the path of the file using which I am deleting the file.

C#

protected void DeleteFile(object sender, EventArgs e)

{

    string filePath = (sender as LinkButton).CommandArgument;

    File.Delete(filePath);

    Response.Redirect(Request.Url.AbsoluteUri);

}

VB.Net

Protected Sub DeleteFile(ByVal sender As Object, ByVal e As EventArgs)

    Dim filePath As String = CType(sender, LinkButton).CommandArgument

    File.Delete(filePath)

    Response.Redirect(Request.Url.AbsoluteUri)

End Sub