File Download button in RadGrid

[M]

I'm trying to create a download link in a RadGrid. What is missing?
How can I get this to work?
Unless someone has a different solution.
Thank you for your help.
Mike

<telerik:RadGrid ID="RadGrid1" runat="server" DataSourceID="SqlDataSource1">
            <MasterTableView autogeneratecolumns="False" datakeynames="id" datasourceid="SqlDataSource1">
            <CommandItemSettings ExportToPdfText="Export to PDF"></CommandItemSettings>

            <RowIndicatorColumn FilterControlAltText="Filter RowIndicator column">
            <HeaderStyle Width="20px"></HeaderStyle>
            </RowIndicatorColumn>

            <ExpandCollapseColumn FilterControlAltText="Filter ExpandColumn column">
            <HeaderStyle Width="20px"></HeaderStyle>
            </ExpandCollapseColumn>

                <Columns>
                    <telerik:GridButtonColumn CommandName="download_file" Text="Download" UniqueName="Download" HeaderText="Download"></telerik:GridButtonColumn>
                    <telerik:GridBoundColumn DataField="id" DataType="System.Int32" FilterControlAltText="Filter id column" HeaderText="id" ReadOnly="True" SortExpression="id" UniqueName="id">
                    </telerik:GridBoundColumn>
                    <telerik:GridBoundColumn DataField="file_name" FilterControlAltText="Filter file_name column" HeaderText="file_name" SortExpression="file_name" UniqueName="file_name">
                    </telerik:GridBoundColumn>
                    <telerik:GridBoundColumn DataField="file_url" FilterControlAltText="Filter file_url column" HeaderText="file_url" SortExpression="file_url" UniqueName="file_url">
                    </telerik:GridBoundColumn>
                </Columns>

            <EditFormSettings>
            <EditColumn FilterControlAltText="Filter EditCommandColumn column"></EditColumn>
            </EditFormSettings>
            </MasterTableView>

            <FilterMenu EnableImageSprites="False"></FilterMenu>

            <HeaderContextMenu CssClass="GridContextMenu GridContextMenu_Default"></HeaderContextMenu>
        </telerik:RadGrid>

protected void RadGrid1_ItemCommand(object source, Telerik.Web.UI.GridCommandEventArgs e)
    {


        if (e.CommandName == "download_file")
        {
            string filename=e.CommandArgument.ToString();
            string path=MapPath("~/files/" + filename);
            byte []bts=System.IO.File.ReadAllBytes(path);
            Response.Clear();
            Response.ClearHeaders();
            Response.AddHeader("Content-Type", "Application/octet-stream");
            Response.AddHeader("Content-Length",bts.Length.ToString());
            Response.AddHeader("Content-Disposition","attachment; filename=" + filename);
            Response.BinaryWrite(bts);
            Response.Flush();
            Response.End();
        }
    }

[Shinu]

Hi Mike,

You will not be able to get the CommandArgument in the ItemCommand event without setting it.Since the sender is the GridButtonColumn, you need to set the CommandArgument in the ASPX. But here I suppose, you need the filename from the DataField 'file_name' which is bound to a BoundColumn.Please check the following code snippet to get the BoundColumn Value in the ItemCommand event.

C#:

protected void RadGrid1_ItemCommand(object sender, Telerik.Web.UI.GridCommandEventArgs e)
{
    if (e.CommandName == "download_file")
    {
        GridDataItem ditem = (GridDataItem)e.Item;
        string filename = ditem["file_name"].Text; // get the filename from the row in which the download button is clicked
        string path = MapPath("/sample/" + filename);
        byte[] bts = System.IO.File.ReadAllBytes(path);
        Response.Clear();
        Response.ClearHeaders();
        Response.AddHeader("Content-Type", "Application/octet-stream");
        Response.AddHeader("Content-Length", bts.Length.ToString());
        Response.AddHeader("Content-Disposition", "attachment; filename=" + filename);
        Response.BinaryWrite(bts);
        Response.Flush();
        Response.End();
    }
}

Thanks,
Shinu.

[M]

Shinu, Thanks for your help, but when I run the code, click on the Download button in the RadGrid, nothing happens.
In debug mode it appears that the 'If (e.CommandName == "download_file") ' isn't being executed.
In the 'browser ' view source here is the code line:

<a href="javascript:__doPostBack('RadGrid1$ctl00$ctl04$ctl01','')">Download</a>

[Shinu]

Hi Mike,

Are you attaching the ItemCommand event for RadGrid? Can you please check whether the ItemCommand event is firing or not. Make sure that you have attached the ItemCommand event in ASPX/C# as follows.

ASPX:

<telerik:RadGrid ID="RadGrid1" runat="server" DataSourceID="SqlDataSource1"
            onitemcommand="RadGrid1_ItemCommand">

OR

C#:

protected void Page_Load(object sender, EventArgs e)
{
   RadGrid1.ItemCommand += new GridCommandEventHandler(RadGrid1_ItemCommand);
}
void RadGrid1_ItemCommand(object sender, GridCommandEventArgs e)
{
   //your code
}

Thanks,
Shinu.

[M]

Thank you that worked.
It's always the simple things ;-)

[Jaime]

Hi, I try his but i have a trouble when click on button to download the function the variable filename don`t get filename from the row "DocumentoConvocatoria". I've tried other fields and get the content correctly but not for column "DocumentosConvocatoria". Reviewing the recorded file name in this field has no spaces at the beginning or end. Any idea???

protected void RadGrid1_ItemCommand(object sender, GridCommandEventArgs e)
{
    if (e.CommandName == "download_file")
    {

        GridDataItem ditem = (GridDataItem)e.Item;

        string filename = ditem["DocumentoConvocatoria"].Text;    // get the filename from the row in which the download button is clicked

        string path = MapPath("Admin/" + filename);

        byte[] bts = System.IO.File.ReadAllBytes(path);

        Response.Clear();

        Response.ClearHeaders();

        Response.AddHeader("Content-Type", "Application/octet-stream");

        Response.AddHeader("Content-Length", bts.Length.ToString());

        Response.AddHeader("Content-Disposition", "attachment; filename=" + filename);

        Response.BinaryWrite(bts);

        Response.Flush();

        Response.End();

    }
}

[Shinu]

Hi,

Please make sure that the column with UniqueName as 'DocumentoConvocatoria' looks and behaves like a Tablecell(GridBoundColumn) in the view mode.

Please elaborate your scenario if it doesn't help.

Regards,
Shinu.

[Manish]

Hi Shinu,

I have saved my files in file stream and i have used a template link button in my radgrid, Now i am trying to download but not able to download that file because i have used ajax manager in my grid and that ajax manager making problem in file save popup

please check my problem as i am in big trouble

On item command
  else if (e.CommandName == "DownloadFile")
                    {

                            SqlConnection objSqlCon = new SqlConnection(db.ConnectionString);
                            objSqlCon.Open();
                            SqlTransaction objSqlTran = objSqlCon.BeginTransaction();

                            SqlCommand objSqlCmd = new SqlCommand("up_Get_Document_File", objSqlCon, objSqlTran);
                            objSqlCmd.CommandType = CommandType.StoredProcedure;

                            SqlParameter objSqlParam1 = new SqlParameter("@FileGUID", SqlDbType.VarChar);
                            objSqlParam1.Value = e.CommandArgument;

                            objSqlCmd.Parameters.Add(objSqlParam1);
                            string path = string.Empty;
                            string FileType = string.Empty;
                            string FormName = string.Empty;

                            using (SqlDataReader sdr = objSqlCmd.ExecuteReader())
                            {
                                while (sdr.Read())
                                {
                                    path = sdr[0].ToString();
                                    FileType = sdr[1].ToString();
                                    FormName = sdr[2].ToString();
                                }

                            }

                            objSqlCmd = new SqlCommand("SELECT GET_FILESTREAM_TRANSACTION_CONTEXT()", objSqlCon, objSqlTran);
                            byte[] objContext = (byte[])objSqlCmd.ExecuteScalar();
                            SqlFileStream objSqlFileStream = new SqlFileStream(path, objContext, FileAccess.Read);
                            byte[] buffer = new byte[(int)objSqlFileStream.Length];
                            objSqlFileStream.Read(buffer, 0, buffer.Length);
                            objSqlFileStream.Close();

                            objSqlTran.Commit();
                            FormName = FormName.Replace(";", "").Replace(",", " ");
                            Response.AddHeader("Content-disposition", "attachment; filename=" + Path.GetFileName(FormName) + FileType);
                            // Here you need to manage the download file stuff according to your need
                            Response.ContentType = "application/octet-stream";
                            Response.BinaryWrite(buffer);
                            Response.End();
                        
                    }

and ajax have ajax manager on my aspx page 
 

[Radoslav]

Hello Manish,

To achieve the desired functionality you can try disabling the ajax when the download link button is pressed. For example:

<telerik:RadAjaxManager ID="RadAjaxManager1" ClientEvents-OnRequestStart="onRequestStart"
        runat="server">

…

function onRequestStart(sender, args) {
  if (args.get_eventTarget().indexOf("DownloadLinkButtonID") >= 0)
    args.set_enableAjax(false);
}

Please give it try and let me know if it helps you.

Regards,
Radoslav
Telerik

 

 

[Payal]

This is not working for me. Is the download code required to be changed according to the type of file we are trying to downlaod

[Radoslav]

Hi Payal,

Could you please elaborate a bit more or your scenario? Why the provided code snippet does not work in your case? Do any error occurs or unexpected results? Also could you please post your aspx markup code with the related code behind file. Thus we will be able to gather more details about your scenario and provide you with more to-the-point answer.

Looking forward for your reply.

Regards,
Radoslav
Telerik

 

 

[Payal]

Thanks for your response.

I could resolve the issue.

[Isaac]

Radoslav,

 

Thank you very much, the information you posted here solved my problem.

To achieve the desired functionality you can try disabling the ajax when the download link button is pressed. For example:
<telerik:RadAjaxManager ID="RadAjaxManager1" ClientEvents-OnRequestStart="onRequestStart"
        runat="server">

…
function onRequestStart(sender, args) {
  if (args.get_eventTarget().indexOf("DownloadLinkButtonID") >= 0)
    args.set_enableAjax(false);
}

Thanks.

[Pronobesh]

Hello Shrinu,

I have written following code, which is not downloading file from Rad Grid control

 

 

<telerik:GridTemplateColumn HeaderText="Request Download" ItemStyle-HorizontalAlign="Center">
                                                <ItemTemplate>
                                                    <asp:ImageButton ID="imgDownload" runat="server" ImageUrl="~/Apps/QMx-CSER/Images/download1.png"
                                                        CommandName="DownloadFile" Height="22px" Width="22px" ToolTip="Request Download"
                                                        CommandArgument='<%# Eval("Job_ID") %>' />
                                                </ItemTemplate>
                                            </telerik:GridTemplateColumn>

 

 

else if (e.CommandName == "DownloadFile")
                {
                    int Job_ID = Convert.ToInt32(e.CommandArgument);
                    string AssemblyNumber = (e.Item.FindControl("lnkItemnumber") as LinkButton).Text;

                    string fullFileName = new SMTPMail().CreateExcel(Job_ID, AssemblyNumber, Session["User"].ToString());
                    string name = Path.GetFileNameWithoutExtension(fullFileName);
                    string extension = Path.GetExtension(fullFileName);
                    string fileName = name + "." + extension;

                    byte[] bts = System.IO.File.ReadAllBytes(fullFileName);
                    Response.Clear();
                    Response.ClearHeaders();
                    Response.AddHeader("Content-Type", "Application/octet-stream");
                    Response.AddHeader("Content-Length", bts.Length.ToString());
                    Response.AddHeader("Content-Disposition", "attachment; filename=" + fileName);
                    Response.BinaryWrite(bts);
                    Response.Flush();
                    File.Delete(fullFileName);
                    Response.End();                   
                }

 

Looking for your help on this.

 

Regards,

Pronobesh Mukherjee

[Pronobesh]

Hello All,
I have written following code, which is not downloading file from Rad Grid control


<telerik:GridTemplateColumn HeaderText="Request Download" ItemStyle-HorizontalAlign="Center">
                                                <ItemTemplate>
                                                    <asp:ImageButton ID="imgDownload" runat="server" ImageUrl="~/Apps/QMx-CSER/Images/download1.png"
                                                        CommandName="DownloadFile" Height="22px" Width="22px" ToolTip="Request Download"
                                                        CommandArgument='<%# Eval("Job_ID") %>' />
                                                </ItemTemplate>
                                            </telerik:GridTemplateColumn>


else if (e.CommandName == "DownloadFile")
                {
                    int Job_ID = Convert.ToInt32(e.CommandArgument);
                    string AssemblyNumber = (e.Item.FindControl("lnkItemnumber") as LinkButton).Text;

                    string fullFileName = new SMTPMail().CreateExcel(Job_ID, AssemblyNumber, Session["User"].ToString());
                    string name = Path.GetFileNameWithoutExtension(fullFileName);
                    string extension = Path.GetExtension(fullFileName);
                    string fileName = name + "." + extension;

                    byte[] bts = System.IO.File.ReadAllBytes(fullFileName);
                    Response.Clear();
                    Response.ClearHeaders();
                    Response.AddHeader("Content-Type", "Application/octet-stream");
                    Response.AddHeader("Content-Length", bts.Length.ToString());
                    Response.AddHeader("Content-Disposition", "attachment; filename=" + fileName);
                    Response.BinaryWrite(bts);
                    Response.Flush();
                    File.Delete(fullFileName);
                    Response.End();                   
                }

Looking for your help on this.

Regards,
Pronobesh Mukherjee

[Marin Bratanov]

Hi Pronobesh,

Make sure the button does not invoke a partial postback. You can only send files to the browser during a full postback. The approach shown by my colleague Radoslav should help you if you are using AJAX for this grid already.

Regards,

Marin Bratanov
Telerik by Progress