Sometimes in a web site you might need the user to upload a zipped file for space issues but the user can’t or doesn’t know how. You might want to conserve space on the server if you have a lot of images. This is also a good way to keep Google from indexing your images from their search. In another article I will show you how to unzip or uncompress but today here is how you can zip an uploaded file. I found a similar article but it was in c#.
As always you need to create a new web application project in Visual Studio and name the project ‘UploadNZip’. Then add a form and add a web reference to iconic.dll. You can get the file from here.
Add the following code to the page.
[code language=”html”]
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:FileUpload ID="file2Upload" runat="server" />
<asp:Button ID="btnZipFile" Text="ZipFile" runat="server" OnClick="btnZipFile_Click" />
<asp:Label ID="lblStatus" runat="server" ForeColor="Red" />
</div>
</form>
[/code]
In the code behind of this form add the following code.
[code language=”vb”]
Protected Sub btnZipFile_Click(sender As Object, e As EventArgs) Handles btnZipFile.Click
‘Zip a File after uploading
If file2Upload.HasFile Then
‘Store the directory for the Zipped File
Dim CurrentPath As String = Server.MapPath("~/ZipFiles/")
‘Get the variables to save the file first to the location
Dim curpath As String = CurrentPath & Path.GetFileName(file2Upload.PostedFile.FileName)
file2Upload.SaveAs(curpath)
Dim filenames As String() = Directory.GetFiles(CurrentPath)
‘As files to the zipped file. This would be one file for this example but could be more
Using zip As New Ionic.Zip.ZipFile()
Dim [date] As String = DateTime.Now.ToString("d")
[date] = [date].Replace("/", "")
zip.AddFiles(filenames, [date])
zip.Save(CurrentPath & [date] & ".zip")
lblStatus.Text = "File Added Successfully"
End Using
If lblStatus.Text = "File Added Successfully" Then
‘Removes the non-zipped file from the folder
File.Delete(curpath)
End If
End If
End Sub
[/code]
Note: See the comments in the code for better understanding
That’s it. It is very simple to implement and can save a lot of space depending on the files you are trying to compress. This library can also allow you to add password protection to the files you compress. A great way to store files that need protection. One scenario would be if someone paid for a document you can then allow them to get the file, enter the password and track how many times this is done.
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Thanks for this and other articles on VB.net. Very helpful. Keep them coming, please!