#Region "Error Provider Extended"
 
''' <summary>
''' Provides a user interface for indicating that a control on a form has an error associated with it.
''' </summary>
Public Class ErrorProviderExtended
 
    Inherits System.Windows.Forms.ErrorProvider
    Private _validationcontrols As New ValidationControlCollection
    Private _summarymessage As String = "Please enter following mandatory fields,"
 
    ''' <summary>
    ''' Gets or sets the summary message.
    ''' This property will be used for displaying a summary message about all empty fields.
    ''' Default value is "Please enter following mandatory fields,". 
    ''' You can set any other message using this property.
    ''' </summary>
    ''' <value>The summary message.</value>
    Public Property SummaryMessage() As String
        Get
            Return _summarymessage
        End Get
        Set(ByVal Value As String)
            _summarymessage = Value
        End Set
    End Property
 
    ''' <summary>
    ''' Gets or sets the controls which should be validated.
    ''' </summary>
    ''' <value>The controls.</value>
    Public Property Controls() As ValidationControlCollection
        Get
            Return _validationcontrols
        End Get
        Set(ByVal Value As ValidationControlCollection)
            _validationcontrols = Value
        End Set
    End Property
 
    ''' <summary>
    ''' Checks the and show summary error message.
    ''' </summary>
    ''' <param name="ShowMessage">
    ''' If set to <c>true</c>, This function displays a message box which contains all the field names which are empty.
    ''' </param>
    ''' <returns><c>true</c> if all fields on form are entered, <c>false</c> otherwise.</returns>
    Public Function CheckAndShowSummaryErrorMessage(Optional ByVal ShowMessage As Boolean = False) As Boolean
 
        If Controls.Count <= 0 Then
            Return True
        End If
 
        Dim i As Integer
        Dim msg As String = SummaryMessage + vbNewLine + vbNewLine
        Dim berrors As Boolean = False
 
        For i = 0 To Controls.Count - 1
 
            If Controls(i).Validate Then
                If Trim(Controls(i).ControlObj.text) = "" Then
                    If ShowMessage Then
                        msg &= "> " & Controls(i).DisplayName & vbNewLine
                    End If
                    SetError(Controls(i).ControlObj, Controls(i).ErrorMessage)
                    berrors = True
                Else
                    SetError(Controls(i).ControlObj, "")
                End If
            Else
                SetError(Controls(i).ControlObj, "")
            End If
 
        Next i
 
        If berrors Then
            If ShowMessage Then
                MessageBox.Show(msg, "Missing Information", MessageBoxButtons.OK, MessageBoxIcon.Stop)
            End If
            Return False
        Else
            Return True
        End If
 
    End Function
 
    ''' <summary>
    ''' Clears error messages from all controls.
    ''' </summary>
    Public Sub ClearAllErrorMessages()
 
        Dim i As Integer
        For i = 0 To Controls.Count - 1
            SetError(Controls(i).ControlObj, "")
        Next
 
    End Sub
 
    ''' <summary>
    ''' Hooks validation event with all controls.
    ''' </summary>
    Public Sub SetErrorEvents()
 
        Dim i As Integer
        For i = 0 To Controls.Count - 1
            AddHandler CType(Controls(i).ControlObj, System.Windows.Forms.Control).Validating, AddressOf Validation_Event
        Next
 
    End Sub
 
    ''' <summary>
    ''' Handles the Event event of the Validation control.
    ''' This event is hooked for all controls,
    ''' it sets an error message with the use of ErrorProvider
    ''' </summary>
    ''' <param name="sender">The source of the event.</param>
    ''' <param name="e">The <see cref="System.ComponentModel.CancelEventArgs"/> instance containing the event data.</param>
    Private Sub Validation_Event(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs)
 
        If Controls(sender).Validate Then
            If Trim(sender.Text) = "" Then
                MyBase.SetError(sender, Controls(sender).ErrorMessage)
            Else
                MyBase.SetError(sender, "")
            End If
        End If
 
    End Sub
 
End Class
 
#End Region
 
#Region "ValidationControlCollection"
 
''' <summary>
''' This class is used for holding all Validation Controls.
''' This class is collection of 'ValidationControl' class objects.
''' This class is used by 'ErrorProviderExtended' class.
''' </summary>
Public Class ValidationControlCollection : Inherits CollectionBase
 
    Default Public Property Item(ByVal ListIndex As Integer) As ValidationControl
        Get
            Return Me.List(ListIndex)
        End Get
        Set(ByVal Value As ValidationControl)
            Me.List(ListIndex) = Value
        End Set
    End Property
 
    Default Public Property Item(ByVal pControl As Object) As ValidationControl
        Get
            If IsNothing(pControl) Then
                Return Nothing
            End If
 
            If GetIndex(pControl.Name) < 0 Then
                Return New ValidationControl
            End If
            Return Me.List(GetIndex(pControl.Name))
        End Get
        Set(ByVal Value As ValidationControl)
            If IsNothing(pControl) Then Exit Property
            If GetIndex(pControl.Name) < 0 Then
                Exit Property
            End If
            Me.List(GetIndex(pControl.Name)) = Value
        End Set
    End Property
 
    Function GetIndex(ByVal ControlName As String) As Integer
        Dim i As Integer
        For i = 0 To Count - 1
            If Item(i).ControlObj.name.toupper = ControlName.ToUpper Then
                Return i
            End If
        Next
        Return -1
    End Function
 
    Public Sub Add(ByRef pControl As Object, ByVal pDisplayName As String)
        If IsNothing(pControl) Then Exit Sub
        Dim obj As New ValidationControl
        obj.ControlObj = pControl
        obj.DisplayName = pDisplayName
        obj.ErrorMessage = "Please enter " + pDisplayName
        Me.List.Add(obj)
    End Sub
 
    Public Sub Add(ByRef pControl As Object, ByVal pDisplayName As String, ByVal pErrorMessage As String)
        If IsNothing(pControl) Then Exit Sub
        Dim obj As New ValidationControl
        obj.ControlObj = pControl
        obj.DisplayName = pDisplayName
        obj.ErrorMessage = pErrorMessage
        Me.List.Add(obj)
    End Sub
 
    Public Sub Add(ByRef pControl As Object)
        If IsNothing(pControl) Then Exit Sub
        Dim obj As New ValidationControl
        obj.ControlObj = pControl
        obj.DisplayName = pControl.Name
        obj.ErrorMessage = "Please enter " + pControl.Name
        Me.List.Add(obj)
    End Sub
 
    Public Sub Add(ByVal pControl As ValidationControl)
        If IsNothing(pControl) Then Exit Sub
        Me.List.Add(pControl)
    End Sub
 
    Public Sub Remove(ByVal pControl As Object)
        If IsNothing(pControl) Then Exit Sub
        Dim i As Integer = Me.GetIndex(pControl.Name)
        If i >= 0 Then
            Me.List.RemoveAt(i)
        End If
    End Sub
End Class
 
#End Region
 
#Region "ValidationControl"
 
''' <summary>
''' ValidationControl class is used to hold any control from windows form. 
''' 'It holds any control in 'ControlObj' property.
''' </summary>
Public Class ValidationControl
 
    Private _control As Object
    Private _displayname As String
    Private _errormessage As String
    Private _validate As Boolean = True
 
    ''' <summary>
    ''' Decides weather control is to be validated. Default value is TRUE.
    ''' </summary>
    ''' <value><c>true</c> if validate; otherwise, <c>false</c>.</value>
    Public Property Validate() As Boolean
        Get
            Return _validate
        End Get
        Set(ByVal Value As Boolean)
            _validate = Value
        End Set
    End Property
 
    ''' <summary>
    ''' ControlObj is a Control from windows form which is to be validated.
    ''' </summary>
    ''' <value>The control object.</value>
    Public Property ControlObj() As Object
        Get
            Return _control
        End Get
        Set(ByVal Value As Object)
            _control = Value
        End Set
    End Property
 
    ''' <summary>
    ''' DisplayName property is used for displaying summary message to user.
    ''' This field name will be displayed in summary message.
    ''' </summary>
    ''' <value>The display name.</value>
    Public Property DisplayName() As String
        Get
            Return _displayname
        End Get
        Set(ByVal Value As String)
            _displayname = Value
        End Set
    End Property
 
    ''' <summary>
    ''' ErrorMessage is also used for displaying summary message.
    ''' </summary>
    ''' <value>The error message.</value>
    Public Property ErrorMessage() As String
        Get
            Return _errormessage
        End Get
        Set(ByVal Value As String)
            _errormessage = Value
        End Set
    End Property
 
End Class
 
#End Region

Public Class ErrorProviderExtended_TestForm
 
    ''' <summary>
    ''' The ErrorProviderExtended instance.
    ''' </summary>
    Private WithEvents MyErrorProvider As New ErrorProviderExtended
 
    ''' <summary>
    ''' Control to validate its content.
    ''' </summary>
    Private WithEvents tbValue As New TextBox
 
    ''' <summary>
    ''' Control that validates general errors.
    ''' </summary>
    Private WithEvents btValidator As New Button
 
    ''' <summary>
    ''' Control that reports the current error message.
    ''' </summary>
    Private lblError As New Label
 
    ''' <summary>
    ''' Control used to indicate a textbox hint.
    ''' </summary>
    Private lblHint As New Label
 
    ''' <summary>
    ''' This value determines whether exists errors that need to be fixed.
    ''' </summary>
    Dim ErrorExists As Boolean = False
 
    Public Sub New()
 
        ' This call is required by the designer.
        InitializeComponent()
 
        With Me.lblHint
            .Location = New Point(10, 10)
            .Text = "Type an 'Int32' value:"
            .ForeColor = Color.WhiteSmoke
            .AutoSize = True
        End With
 
        With Me.tbValue
            .Location = New Point(15, 25)
            .Size = New Size(100, Me.tbValue.Height)
        End With
 
        With Me.lblError
            .Location = New Point(10, 50)
            .Text = ""
            .ForeColor = Color.WhiteSmoke
            .AutoSize = True
        End With
 
        With Me.btValidator
            .Location = New Point(Me.lblError.Location.X, Me.lblError.Location.Y + 20)
            .Text = "Validate"
            .FlatStyle = FlatStyle.System
        End With
 
        With Me
            .MaximizeBox = False
            .StartPosition = FormStartPosition.CenterScreen
            .FormBorderStyle = Windows.Forms.FormBorderStyle.FixedSingle
            .Size = New Point(220, 150)
            .BackColor = Color.FromArgb(34, 34, 36)
            .Controls.AddRange({Me.lblHint, Me.lblError, Me.tbValue, Me.btValidator})
        End With
 
    End Sub
 
    Private Sub Test_Load() Handles Me.Load
 
        With MyErrorProvider
            .Controls.Add(Me.tbValue, "Int32")
            .Controls(Me.tbValue).Validate = True
            .SummaryMessage = "Following fields are mandatory."
        End With
 
        ' Change the textbox text to produce an intentional error.
        tbValue.AppendText(" ")
        tbValue.Clear()
 
    End Sub
 
    Private Sub Button1_Click() _
    Handles btValidator.Click
 
        ' The following function checks all empty fields and returns TRUE if all fields are entered.
        ' If any mandotary field is empty this function displays a message and returns FALSE.
        If MyErrorProvider.CheckAndShowSummaryErrorMessage(ShowMessage:=True) Then
 
            If Not Me.ErrorExists Then
                MessageBox.Show("Data submited successfully.", "", MessageBoxButtons.OK, MessageBoxIcon.Information)
            Else
                MessageBox.Show("Data cannot be submited, fix the error(s).", "", MessageBoxButtons.OK, MessageBoxIcon.Error)
            End If
 
        End If
 
    End Sub
 
    ''' <summary>
    ''' Handles the TextChanged event of the tbValue control.
    ''' </summary>
    Private Sub tbValue_TextChanged(sender As Object, e As EventArgs) _
    Handles tbValue.TextChanged
 
        Dim Value As String = sender.text
 
        If String.IsNullOrEmpty(Value) Then
            MyErrorProvider.SetError(sender, "TextBox is empty.")
 
        ElseIf Not Single.TryParse(Value, New Single) Then
            MyErrorProvider.SetError(sender, "The value cannot contain letters.")
 
        ElseIf Single.TryParse(Value, New Single) Then
 
            If Value > Integer.MaxValue Then
                MyErrorProvider.SetError(sender, "Value is greater than " & CStr(Integer.MaxValue))
            Else ' Remove the error.
                MyErrorProvider.SetError(sender, String.Empty)
            End If
 
        Else ' Remove the error.
            MyErrorProvider.SetError(sender, String.Empty)
 
        End If
 
        Me.lblError.Text = MyErrorProvider.GetError(sender)
 
        If String.IsNullOrEmpty(Me.lblError.Text) Then
            Me.lblError.Text = "No errors :)"
            Me.ErrorExists = False
        Else
            Me.ErrorExists = True
        End If
 
    End Sub
 
End Class
 
 
 

    ' Get Html XPaths
    ' By Elektro
    '
    ' Example Usage:
    '
    ' Dim Document As New HtmlAgilityPack.HtmlDocument
    ' Document.LoadHtml(IO.File.ReadAllText("C:\File.html"))
    ' Dim XpathList As List(Of String) = GetHtmlXPaths(Document)
    ' ListBox1.Items.AddRange((From XPath As String In XpathList Select XPath).ToArray)
 
    ''' <summary>
    ''' Gets all the XPath expressions of an <see cref="HtmlAgilityPack.HtmlDocument"/> document.
    ''' </summary>
    ''' <param name="Document">Indicates the <see cref="HtmlAgilityPack.HtmlDocument"/> document.</param>
    ''' <returns>List(Of System.String).</returns>
    Public Function GetHtmlXPaths(ByVal Document As HtmlAgilityPack.HtmlDocument) As List(Of String)
 
        Dim XPathList As New List(Of String)
        Dim XPath As String = String.Empty
 
        For Each Child As HtmlAgilityPack.HtmlNode In Document.DocumentNode.ChildNodes
 
            If Child.NodeType = HtmlAgilityPack.HtmlNodeType.Element Then
                GetHtmlXPaths(Child, XPathList, XPath)
            End If
 
        Next Child
 
        Return XPathList
 
    End Function
 
    ''' <summary>
    ''' Gets all the XPath expressions of an <see cref="HtmlAgilityPack.HtmlNode"/>.
    ''' </summary>
    ''' <param name="Node">Indicates the <see cref="HtmlAgilityPack.HtmlNode"/>.</param>
    ''' <param name="XPathList">Indicates a ByReffered XPath list as a <see cref="List(Of String)"/>.</param>
    ''' <param name="XPath">Indicates the current XPath.</param>
    Private Sub GetHtmlXPaths(ByVal Node As HtmlAgilityPack.HtmlNode,
                              ByRef XPathList As List(Of String),
                              Optional ByVal XPath As String = Nothing)
 
        XPath &= Node.XPath.Substring(Node.XPath.LastIndexOf("/"c))
 
        Const ClassNameFilter As String = "[@class='{0}']"
        Dim ClassName As String = Node.GetAttributeValue("class", String.Empty)
 
        If Not String.IsNullOrEmpty(ClassName) Then
            XPath &= String.Format(ClassNameFilter, ClassName)
        End If
 
        If Not XPathList.Contains(XPath) Then
            XPathList.Add(XPath)
        End If
 
        For Each Child As HtmlAgilityPack.HtmlNode In Node.ChildNodes
 
            If Child.NodeType = HtmlAgilityPack.HtmlNodeType.Element Then
                GetHtmlXPaths(Child, XPathList, XPath)
            End If
 
        Next Child
 
    End Sub
 

    ' String To HtmlDocument
    ' By Elektro
    '
    ' Example Usage:
    ' Dim Document As HtmlDocument = StringToHtmlDocument(IO.File.ReadAllText("C:\File.html", Text.Encoding.Default))
    '
    ''' <summary>
    ''' Converts a <see cref="String"/> to an <see cref="HTMLDocument"/>.
    ''' </summary>
    ''' <param name="str">Indicates the string.</param>
    ''' <returns>The <see cref="HTMLDocument"/> object.</returns>
    Public Function StringToHtmlDocument(ByVal str As String) As HtmlDocument
 
        Using wb As New WebBrowser
 
            wb.ScriptErrorsSuppressed = True
            wb.DocumentText = ""
            wb.Document.OpenNew(replaceInHistory:=True)
            wb.Document.Write(str)
            Return wb.Document
 
        End Using
 
    End Function

    ' Get XPaths
    ' By Elektro
    '
    ' Example Usage:
    '
    ' Dim xDoc As New Xml.XmlDocument
    ' xDoc.Load("C:\File.xml")
    ' Dim XPathList As List(Of String) = GetXPaths(xDoc)
    ' ListBox1.Items.AddRange((From XPath As String In XPathList Select XPath).ToArray)
 
    ''' <summary>
    ''' Gets all the XPath expressions of an XML Document.
    ''' </summary>
    ''' <param name="Document">Indicates the XML document.</param>
    ''' <returns>List(Of System.String).</returns>
    Public Function GetXPaths(ByVal Document As Xml.XmlDocument) As List(Of String)
 
        Dim XPathList As New List(Of String)
 
        Dim XPath As String = String.Empty
 
        For Each Child As Xml.XmlNode In Document.ChildNodes
 
            If Child.NodeType = Xml.XmlNodeType.Element Then
                GetXPaths(Child, XPathList, XPath)
            End If
 
        Next ' child
 
        Return XPathList
 
    End Function
 
    ''' <summary>
    ''' Gets all the XPath expressions of an XML Node.
    ''' </summary>
    ''' <param name="Node">Indicates the XML node.</param>
    ''' <param name="XPathList">Indicates a ByReffered XPath list as a <see cref="List(Of String)"/>.</param>
    ''' <param name="XPath">Indicates the current XPath.</param>
    Private Sub GetXPaths(ByVal Node As Xml.XmlNode,
                          ByRef XPathList As List(Of String),
                          Optional ByVal XPath As String = Nothing)
 
        XPath &= "/" & Node.Name
 
        If Not XPathList.Contains(XPath) Then
            XPathList.Add(XPath)
        End If
 
        For Each Child As Xml.XmlNode In Node.ChildNodes
 
            If Child.NodeType = Xml.XmlNodeType.Element Then
                GetXPaths(Child, XPathList, XPath)
            End If
 
        Next ' child
 
    End Sub
 

Enumerable.Range(1I, 30I).ToArray ' 1 to 30

ReadOnly FixedValues As Integer() = {1, 5, 19, 22, 34, 55, 66, 88, 99, etc...}

        Combos.ForEach(Sub(comb As List(Of Integer))
                           ListBox1.Items.Add(String.Join(", ", comb))
                       End Sub)
 

        ListBox1.Items.AddRange(
            (From comb As List(Of Integer) In Combos
             Select String.Join(", ", comb)).ToArray
         )
 

Public Class LuisClass_v2
 
    ReadOnly Randomizer As New Random
 
    ReadOnly FixedValues As Integer() =
        Enumerable.Range(1I, 30I).ToArray ' 1 to 30
 
    ReadOnly RandomValues As Integer() =
        Enumerable.Range(FixedValues.First, FixedValues.Last).ToArray ' 1 to 30
 
    Dim Combo As List(Of Integer) = Nothing
    Dim Combos As New List(Of List(Of Integer))
 
    Private Sub Test() Handles MyBase.Shown
 
        Dim IndexCounter As Integer = FixedValues.First ' 1
        Dim LenCounter As Integer = 0I
 
        Const NumStep As Integer = 3I
        Const NumLen As Integer = 10I
 
        Do Until IndexCounter > FixedValues.Last ' IndexCounter > 30
 
            Combo = New List(Of Integer)
 
            For Num As Integer = IndexCounter To (FixedValues.Count) Step NumStep ' 1 to 30 Step 3
 
                Combo.Add(Num)
                LenCounter += 1I
 
                If LenCounter >= NumLen Then
                    Exit For
                End If
 
            Next ' Num
 
            If LenCounter < NumLen Then ' If LenCounter < 10
 
                For RandomNum As Integer = 1I To (NumLen - LenCounter)
 
                    Dim n As Integer = Randomizer.Next(RandomValues.First, RandomValues.Last)
 
                    Do Until Not Combo.Contains(n)
                        n = Randomizer.Next(RandomValues.First, RandomValues.Last)
                    Loop
 
                    Combo.Add(n)
 
                Next ' RandomNum
 
            End If ' LenCounter < NumLen
 
#If DEBUG Then ' #Debug
            Debug.WriteLine(String.Join(", ", Combo))
            ' Stop
#End If
 
            Combos.Add(Combo)
            IndexCounter += 1I
            LenCounter = 0I
 
        Loop ' IndexCounter >= FixedValues.Last
 
        ' ********
        ' Listbox:
        ' ********
        Combos.ForEach(Sub(comb As List(Of Integer))
 
                           ' Convierto la Lista a 'String', le añado los ceros, y añado el string formateado al Listbox.
                           ListBox1.Items.Add(String.Join(", ",
                                                          From value As String In comb
                                                          Select If(value.Length = 1I,
                                                                    value.Insert(0I, "0"c),
                                                                    value)))
 
                       End Sub)
 
    End Sub ' Test
 
End Class

' Multi-Instance Limit Example
' By Elektro
 
' Instructions:
' 1. Open the project properties page, goto 'Application' tab, and click in 'View application Events' button.
' 2. Copy and paste this code to replace the 'MyApplication' class contents.
' 3. Define a proper identifier for 'SemaphID' property.
 
Namespace My
 
    Partial Friend Class MyApplication
 
        ''' <summary>
        ''' The semaphore object used to limit the number of instances.
        ''' </summary>
        Private Semaph As Threading.Semaphore = Nothing
 
        ''' <summary>
        ''' Gets the current semaphore object identifier.
        ''' </summary>
        ''' <value>The current process semaphore identifier.</value>
        ''' <exception cref="System.FormatException">The specified value is not a valid GUID format.</exception>
        Private ReadOnly Property SemaphID As String
            Get
 
                ' Define a Golabl Unique Identifier to name the semaphore object.
                Dim Id As String = "b045ce40-2863-4ce7-a7df-8afca8214454"
 
                If Guid.TryParse(input:=Id, result:=New Guid) Then
                    Return Id
                Else
                    Throw New FormatException("The specified value is not in a valid GUID format.")
                End If
 
            End Get
        End Property
 
        ''' <summary>
        ''' Gets the maximum instances allowed for this process.
        ''' </summary>
        ''' <value>The maximum instances allowed for this process.</value>
        Private ReadOnly Property MaxInstances As Integer
            Get
                Return 3
            End Get
        End Property
 
        ''' <summary>
        ''' Determines whether the semaphore can receive a signal.
        ''' </summary>
        ''' <returns><c>true</c> if this instance [can set semaphore]; otherwise, <c>false</c>.</returns>
        Private Function CanSetSemaphore() As Boolean
 
            Semaph = New Threading.Semaphore(initialCount:=Me.MaxInstances,
                                             maximumCount:=Me.MaxInstances,
                                             name:=Me.SemaphID)
 
            Return Semaph.WaitOne(100I)
 
        End Function
 
        ''' <summary>
        ''' This occurs when the application starts, before the startup Form is created.
        ''' </summary>
        ''' <param name="sender">The source of the event.</param>
        ''' <param name="e">The <see cref="ApplicationServices.StartupEventArgs"/> instance containing the event data.</param>
        Private Sub MyApplication_Startup(ByVal sender As Object, ByVal e As ApplicationServices.StartupEventArgs) _
        Handles Me.Startup
 
            ' If there is more than the maximum allowed instances running with the same id then...
            If Not Me.CanSetSemaphore Then ' Prevent multi-instancing.
 
                MessageBox.Show("This is a limited demo, to run multiple instances please purchase the program.",
                               Application.Info.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error)
 
                ' Cancel the application Startup to terminate the process.
                e.Cancel = True
 
            End If
 
        End Sub
 
        ''' <summary>
        ''' This occurs when the application shuts down.
        ''' </summary>
        ''' <param name="sender">The source of the event.</param>
        ''' <param name="e">The <see cref="EventArgs"/> instance containing the event data.</param>
        Private Sub MyApplication_Shutdown(ByVal sender As Object, ByVal e As EventArgs) _
        Handles Me.Shutdown
 
            If Semaph IsNot Nothing Then
 
                ' Free the semaphore to allow next app runs.
                Semaph.Release()
                Semaph.Close()
                Semaph = Nothing
 
            End If ' semaph IsNot Nothing
 
        End Sub
 
    End Class ' MyApplication
 
End Namespace

' Example of how to add an WPF Control in a WinForms project at execution time.
' By Elektro
 
' Instructions:
' 1. Compile your own WPF user-control or download this one: http://www.codeproject.com/Articles/700185/Windows-Progress-Ring?msg=4884207#xx4884207xx
' 2. Add a reference to 'WindowsformsIntegration', 'PresentationFramework', 'PresentationCore', 'WindowsBase' and 'System.Xaml'.
' 3. Add a reference to our WPF library, in this example is: 'WindowsProgressRing.dll'
' 4. If the 'WindowsProgressRing.dll' user-control doesnt's load properly, set the targeting Framework to '4.5'.
 
#Region " Imports "
 
Imports System.Windows.Forms.Integration ' ElementHost
 
#End Region
 
#Region " WPFControl_TestClass "
 
Public Class WPFControl_TestClass
 
    ''' <summary>
    ''' The ElementHost instance that will host the WPF user-control.
    ''' </summary>
    Dim WPFHost As New ElementHost With {.Dock = DockStyle.Fill}
 
    ''' <summary>
    ''' The WPF user-control instance.
    ''' </summary>
    Dim WPFControl As New NMT.Wpf.Controls.WindowsProgressRing
 
    ''' <summary>
    ''' Initializes a new instance of the <see cref="WPFControl_TestClass"/> class.
    ''' </summary>
    Public Sub New()
 
        ' This call is required by the designer.
        InitializeComponent()
 
        With Me ' Set the Form properties.
            .StartPosition = FormStartPosition.CenterScreen
            .FormBorderStyle = Windows.Forms.FormBorderStyle.FixedSingle
            .MaximizeBox = False
            .ShowIcon = False
            .BackColor = Color.Black
            .Size = New Drawing.Size(320I, 320I)
 
            .Controls.Add(WPFHost) ' Add the ElementHost.
        End With ' Me
 
        With WPFHost ' Set the ElementHost properties.
            .Width = 120I
            .Height = 120I
            WPFHost.Child = WPFControl ' Add the WPF Control.
        End With ' WPFHost
 
        With WPFControl ' Set the WPF Control properties.
            .Items = 60I
            .Width = 120.0R
            .Height = 120.0R
            .Speed = New Windows.Duration(TimeSpan.FromSeconds(2.5R))
            .Background = New Windows.Media.SolidColorBrush(Windows.Media.Color.FromRgb(Color.Black.R, Color.Black.G, Color.Black.B))
            .Foreground = New Windows.Media.SolidColorBrush(Windows.Media.Color.FromRgb(Color.DodgerBlue.R, Color.DodgerBlue.G, Color.DodgerBlue.B))
        End With ' WPFControl
 
    End Sub
 
End Class ' WPFControl_TestClass
 
#End Region

' Single-Instance Application Example
' By Elektro
 
' Instructions:
' 1. Open the project properties page, goto 'Application' tab, and click in 'View application Events' button. 
' 2. Copy and paste this code to replace the 'MyApplication' class contents.
' 3. Define a proper identifier for 'MutexID' property.
 
Namespace My
 
    Partial Friend Class MyApplication
 
#Region " Properties "
 
        ''' <summary>
        ''' Gets the current process mutex identifier.
        ''' </summary>
        ''' <value>the current process mutex identifier.</value>
        ''' <exception cref="System.FormatException">The specified value is not a valid GUID format.</exception>
        Private ReadOnly Property MutexID As String
            Get
                ' Define a Golabl Unique Identifier to name the Mutex.
                Dim Id As String = "b045ce40-2863-4ce7-a7df-8afca8214454"
 
                If Guid.TryParse(input:=Id, result:=New Guid) Then
                    Return Id
                Else
                    Throw New FormatException("The specified value is not in a valid GUID format.")
                End If
 
            End Get
        End Property
 
#End Region
 
#Region " Private Methods "
 
        ''' <summary>
        ''' Determines whether this is the unique instance that is running for this process.
        ''' </summary>
        ''' <returns><c>true</c> if this is the unique instance; otherwise, <c>false</c>.</returns>
        Private Function IsUniqueInstance() As Boolean
 
            Dim mtx As Threading.Mutex = Nothing
 
            Try
                mtx = Threading.Mutex.OpenExisting(name:=Me.MutexID)
                mtx.Close()
                mtx = Nothing
            Catch
                mtx = New Threading.Mutex(initiallyOwned:=True, name:=Me.MutexID)
            End Try
 
            Return mtx IsNot Nothing
 
        End Function
 
#End Region
 
#Region " Event-Handlers "
 
        ''' <summary>
        ''' This occurs when the application starts, before the startup Form is created.
        ''' </summary>
        ''' <param name="sender">The source of the event.</param>
        ''' <param name="e">The <see cref="ApplicationServices.StartupEventArgs"/> instance containing the event data.</param>
        Private Sub MyApplication_Startup(ByVal sender As Object, ByVal e As ApplicationServices.StartupEventArgs) _
        Handles Me.Startup
 
            ' If there is more than one instance running of this process with the same mutex then...
            If Not Me.IsUniqueInstance Then ' Prevent multi-instancing.
 
                MessageBox.Show("This is a limited demo, to run multiple instances please purchase the program.",
                               Application.Info.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error)
 
                ' Cancel the application execution.
                e.Cancel = True
 
            End If
 
        End Sub
 
#End Region
 
    End Class ' MyApplication
 
End Namespace

Public Class LuisClass
 
    ReadOnly Randomizer As New Random
 
    ReadOnly FixedValues As Integer() =
        Enumerable.Range(1I, 30I).ToArray ' 1 to 30
 
    ReadOnly RandomValues As Integer() =
        Enumerable.Range(FixedValues.First, FixedValues.Last).ToArray ' 1 to 30
 
    Private Sub Test() Handles MyBase.Shown
 
        Dim IndexCounter As Integer = FixedValues.First ' 1
        Dim LenCounter As Integer = 0I
 
        Const NumStep As Integer = 3I
        Const NumLen As Integer = 10I
 
        Dim Combo As New List(Of Integer)
        Dim Combos As New List(Of List(Of Integer))
 
        Do Until IndexCounter > FixedValues.Last ' IndexCounter > 30
 
            For Num As Integer = IndexCounter To (FixedValues.Count) Step NumStep ' 1 to 30 Step 3
 
                Combo.Add(Num)
                LenCounter += 1I
 
                If LenCounter >= NumLen Then ' Esto no es necesario en este ejemplo porque siempre dará Falso, pero lo dejo aquí.
                    Exit For
                End If
 
            Next ' Num
 
            If LenCounter < NumLen Then ' If LenCounter < 10
 
                For RandomNum As Integer = 1I To (NumLen - LenCounter)
 
                    Dim n As Integer = Randomizer.Next(RandomValues.First, RandomValues.Last)
 
                    Do Until Not Combo.Contains(n)
                        n = Randomizer.Next(RandomValues.First, RandomValues.Last)
                    Loop
 
                    Combo.Add(n)
 
                Next ' RandomNum
 
            End If ' LenCounter < NumLen
 
#If DEBUG Then ' #Debug
            Debug.WriteLine(String.Join(", ", Combo))
            ' Stop
#End If
 
            Combos.Add(Combo)
            Combo.Clear()
 
            IndexCounter += 1I
            LenCounter = 0I
 
        Loop ' IndexCounter >= FixedValues.Last
 
    End Sub ' Test
 
End Class