How to split a procedure in few logic parts? - vb.net

Question

Hi, I'm creating a downloader by halving it in steps so that each part works logically.
The code is divided into:
public class Form1
Public Shared link As String 'I'm sharing data with another form
I insert a url to download in the textchanged event of textbox:
If (My.Settings.Cartellasalvataggio = "") Then
Label2.Text = "Download folder is missing"
' MsgBox("manca destinazione")
Else
If Clipboard.GetText.Contains("youtube") = False Then
Label2.Text = "not a valid youtube link"
Else
If TextBox1.Text = Clipboard.GetText Then
Label2.Text = "you already use it"
Else
TextBox1.Text = Clipboard.GetText
WebBrowser1.Navigate("https://www.320youtube.com/v8/watch?v=" +
_TextBox1.Text.Replace("https://www.youtube.com/watch?v=", ""))
End If
End If
End If
Then, in the document completed event I extract the download link:
Private Sub WebBrowser1_DocumentCompleted(sender As Object, e As WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted
Dim collection As HtmlElementCollection = WebBrowser1.Document.All
Dim a As String
For Each element As HtmlElement In collection
If element.TagName = "A" Then
a = element.GetAttribute("HREF")
If a.Length > 70 Then
a.ToString.Replace(" - YouTube", "")
link = a
If link IsNot Nothing Then
Title()
End If
End If
End If
Next
End Sub
If the link variable is not empty then I activate the sub title:
Private Sub Title()
Dim wctitolo As New WebClient()
wctitolo.Encoding = Encoding.UTF8
Dim source As String = wctitolo.DownloadString(TextBox1.Text.Replace(" - YouTube", ""))
Dim title As String = Regex.Match(source, "\<title\b[^>]*\>\s*(?<Title>[\s\S]*?)\</title\>", RegexOptions.IgnoreCase).Groups("Title").Value
Dim a As String = title.Replace(" - YouTube", "")
Dim webdecode As String = WebUtility.HtmlDecode(a)
My.Settings.Titolo = String.Join("-", webdecode.Split(IO.Path.GetInvalidFileNameChars))
Label2.Text = "Getting title..- Step 3/4"
Label1.Text = My.Settings.Titolo
RichTextBox1.AppendText(vbLf + My.Settings.Titolo + Environment.NewLine)
formcs.BetterListBox1.Items.Add(My.Settings.Titolo)
My.Settings.Save()
If Fileexist() Then
Else
If My.Settings.Titolo IsNot Nothing Then
Download()
End If
End If
and sub FileExists () which returns true if the file exists and false if it does not exist. If it does not exist then, as dictated in private sub Title (), I activate the private sub Download ().
Public Function Fileexist() As Boolean
Label3.Text = Label3.Text + "Fileesiste+ "
Dim result As Boolean
Dim cartella = My.Settings.Cartellasalvataggio
Dim filedidestinazione = Directory.GetFiles(cartella,
My.Settings.Titolo + ".mp3",
SearchOption.AllDirectories).FirstOrDefault()
If filedidestinazione IsNot Nothing Then
Dim answer As String
answer = CType(MsgBox("File exist in" + vbLf + My.Settings.Cartellasalvataggio + "\" + My.Settings.Titolo + ".mp3" + vbLf + "Would you like to open the folder?", vbYesNo), String)
If CType(answer, Global.Microsoft.VisualBasic.MsgBoxResult) = vbYes Then
Process.Start("explorer.exe", "/select," & filedidestinazione)
result = True
Else
result = False
answer = CType(vbNo, String)
Label2.Text = "File exist"
End If
End If
Return result
End Function
and at the end, the Download sub:
Public WithEvents mclient As New WebClient
Private Sub mClient_DownloadProgressChanged(sender As Object, e As DownloadProgressChangedEventArgs) Handles mclient.DownloadProgressChanged
Try
Label4.Text = (Val(e.BytesReceived) / 1048576).ToString("0.00") & "MB Scaricati"
Label2.Text = "Download di " + My.Settings.Titolo + " in corso.."
Catch ex As Exception
End Try
End Sub
Private Sub Download()
Label3.Text = Label3.Text + "Download+ "
Dim filepath As String = (My.Settings.Cartellasalvataggio + "\" + Label1.Text + ".mp3")
mclient.Encoding = Encoding.UTF8
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12
mclient.Headers.Add(HttpRequestHeader.UserAgent, "")
mclient.DownloadFileAsync(New Uri(link), filepath)
End Sub
I thought everything was fine, but at runtime I get an error for stackoverflow ..
The "Settings.Designer.vb" tab opens with the error
System.StackOverflowException in
<Global.System.Configuration.UserScopedSettingAttribute(), _
Global.System.Diagnostics.DebuggerNonUserCodeAttribute(), _
Global.System.Configuration.DefaultSettingValueAttribute("")> _
Public Property Titolo() As String
Get
Return CType(Me("Titolo"),String)
End Get
Set
Me("Titolo") = value
End Set
End Property
is there an easy way I can concatenate these pieces of code in such a way that they work in a logical step by step without modifying to much the code?
Thank you