Sub executed before another - vb.net

Question

I have the following sub
Public Sub Transfer()
Dim i As Integer
Dim j As Integer
Dim k As Integer
Dim Searching_Date As String
Dim Name As String
Dim Presente As Boolean
Dim Foto_Presente As Boolean
For i = 0 To CDIi - 1
Searching_Date = Image_Date(Camera_Day_Images(i))
Name = Replace(Camera_Day_Images(i), Camera & Path_in_Camera & "\", "")
Presente = False
j = 0
While (Not Presente And j <= PCi)
If (Path & "\" & Right_Date(Searching_Date)) = PC_Directory(j) Then
Presente = True
Else
Presente = False
End If
j = j + 1
End While
If Presente = True Then
Foto_Presente = False
k = 0
List_PC_Day_Images(Path & "\" & Right_Date(Searching_Date))
While (Not Foto_Presente And k <= PDIi)
If (Path & "\" & Right_Date(Searching_Date) & "\" & Name) = PC_Day_Images(k) Then
Foto_Presente = True
Else
Foto_Presente = False
End If
k = k + 1
End While
If Foto_Presente = True Then
Else
My.Computer.FileSystem.CopyFile(Camera & Path_in_Camera & "\" & Name, Path & "\" & Right_Date(Searching_Date) & "\" & Name)
PC_Day_Images(PDIi) = Path & "\" & Right_Date(Searching_Date) & "\" & Name
PDIi = PDIi + 1
End If
Else
My.Computer.FileSystem.CreateDirectory(Path & "\" & Right_Date(Searching_Date))
My.Computer.FileSystem.CopyFile(Camera & Path_in_Camera & "\" & Name, Path & "\" & Right_Date(Searching_Date) & "\" & Name)
End If
Next
Principale.LFine.Text = "Tutte le tue foto sono state trasferite con successo"
Principale.Button1.Enabled = False
End Sub
It copies any photos from my device to my computer. So if I have a lot of photos It can take several time and I want to notify this. In fact I change the text in the label, than I call the Sub and finally rechange the label.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
LFine.Text = "attendere prego..."
Transfer()
LFine.Text = "Operazione completata con successo"
End Sub
But the results are that Transfer () starts and just after he finished changing the label.
Why??? How can I fix this problem??
Thank you.

Answer 1

After LFine.Text = "attendere prego..." add this line:
LFine.Update()
See https://msdn.microsoft.com/en-us/library/vstudio/system.windows.forms.control.update(v=vs.100).aspx

Answer 2

Wrap the call to tranfers() in an if statement
Change your Sub to a Function,
Public Function Transfer() As Boolean
...
then
If tranfers() = true then
LFine.Text = "Operazione completata con successo"
End if

Answer 3

That is because your process is a blocking process. The label is "updated" but the form is redrawn only after the whole process ends. Others have suggested to use Application.DoEvents() or LFine.Update, but the best way to do what you want is to make your process parallel.
You could use a BackgroundWorker for this:
Imports System.ComponentModel
Dim bgw As New BackgroundWorker
In the Load event of your form...
AddHandler bgw.DoWork, AddressOf bgw_DoWork
AddHandler bgw.RunWorkerCompleted, AddressOf bgw_RunWorkerCompleted
And then set your code like this...
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
LFine.Text = "attendere prego..."
bgw.RunWorkerAsync()
End Sub
Private Sub bgw_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles bgw.DoWork
Dim i As Integer
Dim j As Integer
Dim k As Integer
Dim Searching_Date As String
Dim Name As String
Dim Presente As Boolean
Dim Foto_Presente As Boolean
For i = 0 To CDIi - 1
Searching_Date = Image_Date(Camera_Day_Images(i))
Name = Replace(Camera_Day_Images(i), Camera & Path_in_Camera & "\", "")
Presente = False
j = 0
While (Not Presente And j <= PCi)
If (Path & "\" & Right_Date(Searching_Date)) = PC_Directory(j) Then
Presente = True
Else
Presente = False
End If
j = j + 1
End While
If Presente = True Then
Foto_Presente = False
k = 0
List_PC_Day_Images(Path & "\" & Right_Date(Searching_Date))
While (Not Foto_Presente And k <= PDIi)
If (Path & "\" & Right_Date(Searching_Date) & "\" & Name) = PC_Day_Images(k) Then
Foto_Presente = True
Else
Foto_Presente = False
End If
k = k + 1
End While
If Foto_Presente = True Then
Else
My.Computer.FileSystem.CopyFile(Camera & Path_in_Camera & "\" & Name, Path & "\" & Right_Date(Searching_Date) & "\" & Name)
PC_Day_Images(PDIi) = Path & "\" & Right_Date(Searching_Date) & "\" & Name
PDIi = PDIi + 1
End If
Else
My.Computer.FileSystem.CreateDirectory(Path & "\" & Right_Date(Searching_Date))
My.Computer.FileSystem.CopyFile(Camera & Path_in_Camera & "\" & Name, Path & "\" & Right_Date(Searching_Date) & "\" & Name)
End If
Next
End Sub
Private Sub bgw_RunWorkerCompleted(ByVal sender As System.Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles bgw.RunWorkerCompleted
Principale.LFine.Text = "Tutte le tue foto sono state trasferite con successo"
Principale.Button1.Enabled = False
End Sub
Just make sure you don't access any control of your form inside bgw_DoWork method.