Download Files From GridView Link Button In Asp.Net C# VB.NET

This Example explains how to Download Files From GridView Link Button In Asp.Net Using C# VB.NET when files are saved or stored on server and their path or file name is saved in sql server database.

I have placed one FileUpload control on the page to upload files on the server, and saving id and file name in database.

GridView on the page is used to display uploaded file and provide download link.

Create one table in sql database and add two columns ID (int identity) and FileName(Varchar).


HTML SOURCE OF PAGE

---

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

   2:  <asp:Button ID="btnUpload" runat="server" 

   3:              onclick="btnUpload_Click" 

   4:              Text="Upload" />

   5:  <asp:Label ID="lblMessage" runat="server"></asp:Label>

   6:   

   7:  <asp:GridView ID="GridView1" runat="server" 

   8:                AutoGenerateColumns="False" 

   9:                DataSourceID="SqlDataSource1" 

  10:                onrowcommand="GridView1_RowCommand">

  11:  <Columns>

  12:  <asp:BoundField DataField="ID" HeaderText="ID" 

  13:                  SortExpression="ID" />

  14:  <asp:BoundField DataField="FileName" 

  15:                  HeaderText="FileName" 

  16:                  SortExpression="FileName" />

  17:   

  18:  <asp:ButtonField ButtonType="Link" Text="Download" 

  19:                   CommandName="Dwn" 

  20:                   HeaderText="Files" />

  21:  </Columns>

  22:  </asp:GridView>

  23:  <asp:SqlDataSource ID="SqlDataSource1" runat="server" 

  24:  ConnectionString=

  25:  "<%$ ConnectionStrings:ConnectionString %>" 

  26:  SelectCommand="SELECT [ID], [FileName] 

  27:                 FROM [Files]">

  28:  </asp:SqlDataSource>

Write below mentioned code in Click Event of upload button

C#

---

protected void btnUpload_Click(object sender, EventArgs e)
    {
        if (FileUpload1.HasFile)
        {
            string name = Path.GetFileName(FileUpload1.PostedFile.FileName);
            string location = Server.MapPath("~/Docs/" + name);
            FileUpload1.SaveAs(location);

            //Create SQL Connection and Command to Save File name in DataBase

            string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
            SqlConnection sqlCon = new SqlConnection(connectionString);
            string strInsert = "INSERT INTO Files(FileName) VALUES(@FileName)";
            SqlCommand command = new SqlCommand(strInsert, sqlCon);
            command.Parameters.AddWithValue("@FileName", name);
            sqlCon.Open();
            int result = command.ExecuteNonQuery();
            sqlCon.Close();

            if (result > 0)
                lblMessage.Text = "Upload Successful";
        }
        GridView1.DataBind();
    }

VB.NET

---

Protected Sub btnUpload_Click(sender As Object, e As EventArgs)
 If FileUpload1.HasFile Then
  Dim name As String = Path.GetFileName(FileUpload1.PostedFile.FileName)
  Dim location As String = Server.MapPath("~/Docs/" & name)
  FileUpload1.SaveAs(location)

  'Create SQL Connection and Command to Save File name in DataBase

  Dim connectionString As String = ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString
  Dim sqlCon As New SqlConnection(connectionString)
  Dim strInsert As String = "INSERT INTO Files(FileName) VALUES(@FileName)"
  Dim command As New SqlCommand(strInsert, sqlCon)
  command.Parameters.AddWithValue("@FileName", name)
  sqlCon.Open()
  Dim result As Integer = command.ExecuteNonQuery()
  sqlCon.Close()

  If result > 0 Then
   lblMessage.Text = "Upload Successful"
  End If
 End If
 GridView1.DataBind()
End Sub

Write this code in RowCommand Event of GridView

C#

---

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "Dwn")
        {
            int index = Convert.ToInt32(e.CommandArgument);
            GridViewRow row = GridView1.Rows[index];
            string fName = row.Cells[1].Text;
            Response.ContentType = "application/octet-stream";
            Response.AddHeader("Content-Disposition", "attachment;filename=" + fName);
            Response.TransmitFile(Server.MapPath("~/Docs/" + fName));
            Response.End();
        }
    }

VB.NET

---

Protected Sub GridView1_RowCommand(sender As Object, e As GridViewCommandEventArgs)
 If e.CommandName = "Dwn" Then
  Dim index As Integer = Convert.ToInt32(e.CommandArgument)
  Dim row As GridViewRow = GridView1.Rows(index)
  Dim fName As String = row.Cells(1).Text
  Response.ContentType = "application/octet-stream"
  Response.AddHeader("Content-Disposition", "attachment;filename=" & fName)
  Response.TransmitFile(Server.MapPath("~/Docs/" & fName))
  Response.[End]()
 End If
End Sub

Build and run the application

Download Sample Code

Tweet

If you like this post than join us or share