Random delay in seconds from numericupdown in VB.Net - vb.net

Question

I have a desktop winforms app code:
Sub Delay(ByVal dblSecs As Double)
Const OneSec As Double = 1.0# / (1440.0# * 60.0#)
Dim dblWaitTil As Date
Now.AddSeconds(OneSec)
dblWaitTil = Now.AddSeconds(OneSec).AddSeconds(dblSecs)
Do Until Now > dblWaitTil
Application.DoEvents()
Loop
End Sub
Private Sub btnStart_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStart.Click
Webbrowser1.Navigate(TextBox1.Text)
Delay(Val(DelayText.Text))
end sub
What I need is to set max. delay, same from textbox by entering seconds.
I need this to be random delay number so Im stacking here, thanks for correcting my code.
Also If its possible to make it in NumericUpDown, as i found some topics which says textbox text property is different as NumericUpDown but i like it more.

Answer 1

You could use an inbetween class which does most of the work for you
This class would take the WebBrowser, attach to some events of it, and would refresh periodically (depending on MinimumWait / MaximumWait)
As it is using threading, it also checks if the usercontrol needs to be invoked to Refresh it and when yes, invokes the custom refresh delegate
Public Class Refresher
Protected Delegate Sub RefreshNavigationDelegate(browser As WebBrowser)
Protected Sub RefreshNavigation(browser As WebBrowser)
If browser.InvokeRequired Then
browser.Invoke(New RefreshNavigationDelegate(AddressOf RefreshNavigation), browser)
Return
End If
browser.Refresh(WebBrowserRefreshOption.Completely)
End Sub
Private _isBusy As Boolean = False
Public Property IsBusy As Boolean
Get
Return _isBusy
End Get
Protected Set(value As Boolean)
If _isBusy = value Then
Return
End If
_isBusy = value
End Set
End Property
Public Property MinimumWait As Integer = 2000
Public Property MaximumWait As Integer = 10000
Private refreshThread As Thread = Nothing
Private _browser As WebBrowser
Public Property Browser As WebBrowser
Get
Return _browser
End Get
Set(value As WebBrowser)
If Object.Equals(_browser, value) Then
Return
End If
StopRefresh()
If _browser IsNot Nothing Then
RemoveHandler Browser.DocumentCompleted, AddressOf DocumentComplete
RemoveHandler Browser.Navigating, AddressOf Navigating
End If
_browser = value
If _browser IsNot Nothing Then
AddHandler Browser.DocumentCompleted, AddressOf DocumentComplete
AddHandler Browser.Navigating, AddressOf Navigating
AddHandler Browser.ProgressChanged, AddressOf ProgressChanged
End If
StartRefresh()
End Set
End Property
Protected Sub ProgressChanged(sender As Object, e As WebBrowserProgressChangedEventArgs)
IsBusy = e.CurrentProgress > 0 AndAlso e.CurrentProgress < e.MaximumProgress
End Sub
Protected Sub DocumentComplete(sender As Object, e As WebBrowserDocumentCompletedEventArgs)
IsBusy = False
End Sub
Protected Sub Navigating(sender As Object, e As WebBrowserNavigatingEventArgs)
IsBusy = True
End Sub
Public Sub StartRefresh()
If refreshThread IsNot Nothing Then
Return
End If
refreshThread = New Thread(AddressOf DoRandomRefreshes)
refreshThread.Start()
End Sub
Public Sub StopRefresh()
If refreshThread Is Nothing Then
Return
End If
refreshThread.Abort()
refreshThread = Nothing
End Sub
Protected Overridable Sub DoRandomRefreshes()
Dim randomGenerator As New Random()
While Not refreshThread.ThreadState = ThreadState.AbortRequested
Dim newTimeout As Integer = MinimumWait + randomGenerator.Next(MaximumWait - MinimumWait)
Thread.Sleep(newTimeout)
If Not IsBusy Then
RefreshNavigation(Browser)
End If
End While
End Sub
Public Sub New()
End Sub
End Class
You could then use it in your form as such:
Public Class Form1
Dim myRefresher As Refresher = New Refresher()
Private Sub tsbGo_Click(sender As Object, e As EventArgs) Handles tsbGo.Click
WebBrowser1.Navigate(txtUrl.Text)
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
myRefresher.Browser = WebBrowser1
End Sub
Private Sub txtMin_TextChanged(sender As Object, e As EventArgs) Handles txtMin.TextChanged
Dim int As Integer = 0
If Integer.TryParse(txtMin.Text, int) Then
myRefresher.MinimumWait = int
End If
End Sub
Private Sub txtMax_TextChanged(sender As Object, e As EventArgs) Handles txtMax.TextChanged
Dim int As Integer = 0
If Integer.TryParse(txtMax.Text, int) Then
myRefresher.MaximumWait = int
End If
End Sub
End Class