In my previous article I had made use of <INPUT id="fileUpload" type="file" Runat="server" NAME="fileUpload"> to upload file, in asp.net we have new server side control called as "FileUpload control"
The FileUpload control does not automatically save a file to the server after the user selects the file to upload. You must explicitly provide a control or mechanism to allow the user to submit the specified file.
Uploading single file functionality at a time to the server this functionality we have already achieved in the earlier article.
Here I am going to display small code snippet by using which you can upload multiple files at a time.
The idea is you can select files from your folders and keep on adding to listbox and in one shot you can upload all the files I have provided functionalities like "Add", "Remove" & "Upload", technically speaking I am adding to the static arraylist and considering each array element as System.Web.UI.WebControls.FileUpload , while uploading just iterate through each webcontrol and SaveAs file to the specified location.
Note: To upload any of the file in respective folder user need to have permission for writing to the folder so please follow the following steps to prevent from the error.
Set permission to virtual directory by following steps in IIS:
Right Click on virtual directory which you have created for this project. Under directory Tab you will find :
1. Read.
2. Log Visits.
Index this resources are marked as checked (enables) in addition to this make:
Write access enabled or checked. -> Click on Apply. -> Click on OK.
Code for uploader.ascx:
<%@ Control Language="VB" AutoEventWireup="true" CodeFile="Uploader.ascx.vb" Inherits="Uploader" %>
<table>
<tr>
<td style="width: 163px">
<span style="font-size: 10pt; font-family: Verdana"><strong>
Select file to upload:</strong></span></td>
<td style="width: 324px">
<asp:FileUpload ID="fUpload" runat="server" /> <asp:Button ID="btnAdd" runat="server" Text="Add"
OnClick="btnAdd_Click" /></td>
</tr>
<tr>
<td style="width: 163px">
</td>
<td style="width: 324px">
<asp:ListBox ID="lstFiles" runat="server" Width="324px"></asp:ListBox>
</td>
</tr>
<tr>
<td style="width: 163px">
</td>
<td style="width: 324px">
<asp:Button ID="btnRemove" runat="server" Text="Remove" OnClick="btnRemove_Click" />
<asp:Button ID="btnUpload" runat="server" Text="Upload" OnClick="btnUpload_Click" /></td>
</tr>
<tr>
<td colspan="2">
<asp:Label ID="lblMessage" runat="server" Font-Names="Verdana" Font-Size="Small"
ForeColor="Red"></asp:Label></td>
</tr>
</table>
Code for uploader.ascx.vb:
Protected Shared arrFiles As New ArrayList()
Protected isUploaded As Integer = 0
Protected pathToUpload As String = HttpContext.Current.Server.MapPath("UploadedFiles")
'General declerations
' has to be static since Adding and then reusing
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
End Sub
Protected Sub btnAdd_Click(ByVal sender As Object, ByVal e As EventArgs)
'Functionality to add the item in the list
'At very first add to the array list & simultanously display in the listbox
Try
If Page.IsPostBack Then
arrFiles.Add(fUpload)
lstFiles.Items.Add(fUpload.PostedFile.FileName)
End If
Catch ex As Exception
lblMessage.Text = "An error has occured while adding file" + ex.Message
End Try
End Sub
Protected Sub btnRemove_Click(ByVal sender As Object, ByVal e As EventArgs)
'Functionality to remove files
'Veryfirst you have to remove from the arraylist and similarly from the listbox
If lstFiles.Items.Count <> 0 Then
arrFiles.Remove(fUpload)
lstFiles.Items.Remove(lstFiles.SelectedItem.Text)
End If
End Sub
Protected Sub btnUpload_Click(ByVal sender As Object, ByVal e As EventArgs)
'Very first check if the files are present to upload or Selected to upload
If (lstFiles.Items.Count = 0) AndAlso (isUploaded = 0) Then
lblMessage.Text = "Please specify file name"
Else
'Take every element from the arraylist as HTMLInputFile, iterate through
'each InputFile and upload the files to the specified location
For Each Ipf As System.Web.UI.WebControls.FileUpload In arrFiles
Try
Dim strFileName As String = System.IO.Path.GetFileName(Ipf.PostedFile.FileName)
Ipf.PostedFile.SaveAs(pathToUpload + "\" + strFileName)
isUploaded = isUploaded + 1
Catch ex As Exception
lblMessage.Text = "An error has occured while uploading your files:<br>" + ex.Message
End Try
Next
If isUploaded = arrFiles.Count Then
lblMessage.Text = "Files uploaded successfully"
End If
'Empty the arraylist and listbox once the upload process finishes
arrFiles.Clear()
lstFiles.Items.Clear()
End If
End Sub
Accessing Code on Default.aspx page:
<%@ Page Language="VB" AutoEventWireup="true" CodeFile="Default.aspx.vb" Inherits="_Default" %>
<%@ Register TagPrefix="Bulk" TagName="Uploader" Src="Uploader.ascx" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Bulk Uploader</title>
</head>
<body>
<form id="attachme" method="post" enctype="multipart/form-data" runat="server">
<div>
<h3>
Bulk Files Uploader Utility:</h3>
<Bulk:Uploader runat="server" id="Uploader1">
</Bulk:Uploader>
</div>
</form>
</body>
</html>
NOTE: THIS ARTICLE IS CONVERTED FROM C# TO VB.NET USING A CONVERSION TOOL. ORIGINAL ARTICLE CAN BE FOUND ON C# Corner (http://www.c-sharpcorner.com/).