(adsbygoogle = window.adsbygoogle || []).push({}); One of my friend asked me to make an updater for him. Well, even if there are a lot of sources about this on the net, I think I did a pretty good job so I'm giving this out as open source.


Credits also to idb who shared his CountOccurrence function with the community.


Sample:
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Usage:
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The .txt file must follow this structure:

    (last product version)|(lastest version doanload link)|(optional: changelogs, putting a "/" equals to a new line)

Code:

    

Class Updater





    Private DownloadLink As String = String.Empty

    Private Bar As New ProgressBar With {.Location = New Point(10, 180), .Height = 15, .Width = 320}





#Region "Forms"





    Delegate Sub ChangeFormStatus(ByVal F As Form, ByVal Var As Boolean)

    Sub ChangeStatus(ByVal Var As Boolean)

  For Each F As Form In My.Application.OpenForms

    F.Invoke(New ChangeFormStatus(AddressOf SingleFormChange), New Object() {F, Var})

  Next

    End Sub

    Sub SingleFormChange(ByVal F As Form, ByVal Var As Boolean)

  If Var Then

    F.Show()

  Else

    F.Hide()

  End If

    End Sub





#End Region





    Sub New(ByVal Link As String, ByVal ForceUpdate As Boolean)

  Dim T As New Threading.Thread(Sub() CheckUpdates(Link, ForceUpdate))

  T.Start()

    End Sub





    Sub CheckUpdates(ByVal Link As String, ByVal ForceUpdate As Boolean)

  ChangeStatus(False)

  If Not System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable() Then : Exit Sub : End If

  Dim Version = String.Empty, Changelog As String = String.Empty





  Dim resp As String = New Net.WebClient().DownloadString(Link)

  Version = resp.Split("|")(0)

  DownloadLink = resp.Split("|")(1)

  If CountOccurance(resp, "|", True) > 1 Then : Changelog = resp.Split("|")(2) : End If





  If Version = Application.ProductVersion.ToString Then

    ChangeStatus(True)

  Else

    If ForceUpdate Then

    CreateForm(Changelog)

    Else

    Select Case MessageBox.Show("A new updated version is available, would you like to update now?", "Update Available", MessageBoxButtons.YesNoCancel)

    Case DialogResult.Yes

    CreateForm(Changelog)

    Case DialogResult.No

    ChangeStatus(True)

    Case DialogResult.Cancel

    End

    End Select

    End If





  End If

    End Sub





    Function CountOccurance(ByVal Data As String, ByVal Search As String, Optional ByVal CaseSensitive As Boolean = False) As Integer

  'credits to idb

  Return (IIf(CaseSensitive, (Data.Length - (Data.Replace(Search, "").Length)), (Data.Length - (Data.ToLower.Replace(Search.ToLower, "").Length))) / Search.Length)

    End Function





#Region "Form Processes"





    Private Sub CreateForm(ByVal Changelog As String)

  Dim Frm As New Form With {.Size = New Size(350, 240), .Text = "Updating...", .StartPosition = FormStartPosition.CenterScreen, .FormBorderStyle = FormBorderStyle.FixedDialog}

  Frm.Controls.Add(New Label With {.Text = "The process will take few seconds...", .Location = New Point(10, 20), .Width = 270})

  Frm.Controls.Add(New Label With {.Text = "Changelogs:", .Location = New Point(10, 43), .Width = 100, .Height = 15})

  Frm.Controls.Add(New TextBox With {.Multiline = True, .ScrollBars = ScrollBars.Vertical, .Location = New Point(10, 65), .Height = 100, .Width = 320, .Enabled = False, .Text = IIf(String.IsNullOrWhiteSpace(Changelog), Nothing, Changelog.Replace("/", vbNewLine))})

  Frm.Controls.Add(Bar)

  AddHandler Frm.Load, AddressOf LoadDownloadForm

  AddHandler Frm.FormClosing, AddressOf FormClosing

  Application.Run(Frm)

    End Sub





    Private Sub LoadDownloadForm()

  Dim w As New Net.WebClient

  AddHandler w.DownloadProgressChanged, AddressOf ProgressChanged

  AddHandler w.DownloadFileCompleted, AddressOf DownloadCompleted

  w.DownloadFileAsync(New Uri(DownloadLink), Application.StartupPath & "\" & IO.Path.GetFileNameWithoutExtension(Application.ExecutablePath) & "Updated.exe")

    End Sub





    Private Sub ProgressChanged(ByVal sender As Object, ByVal e As Net.DownloadProgressChangedEventArgs)

  Dim bytesScaricati As Double = Double.Parse(e.BytesReceived.ToString())

  Dim bytesTotali As Double = Double.Parse(e.TotalBytesToReceive.ToString())

  Dim percentage As Double = (bytesScaricati / bytesTotali * 100)

  Bar.Value = Int32.Parse(Math.Truncate(percentage).ToString())

    End Sub





    Private Sub DownloadCompleted(ByVal sender As Object, ByVal e As System.ComponentModel.AsyncCompletedEventArgs)

  Process.Start(Application.StartupPath & "\" & IO.Path.GetFileNameWithoutExtension(Application.ExecutablePath) & "Updated.exe")

  Dim Close As New ProcessStartInfo With {.FileName = "cmd.exe", .WindowStyle = ProcessWindowStyle.Hidden}

  Close.Arguments = "/C ping 1.1.1.1 -n 1 -w 2000 > Nul & Del """ & Application.ExecutablePath & """"

  Process.Start(Close)

  End

    End Sub





    Private Sub FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs)

  e.Cancel = True

    End Sub





#End Region





End Class

Nicely done, I did this to check an XML file on my host and if the application build number was less than that in the XML file, then it would prompt the user to update.