Найти количество повторяющихся элементов в массиве

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim X(10) As Integer
        Dim a As Integer
        Dim b As Integer
        Dim i As Integer
        Randomize()
        a = TextBox1.Text
        b = TextBox2.Text
        For i = 0 To 10
            X(i) = Int((b - a + 1) * Rnd() + a) 'Заполнение массива
        Next i
        Dim foundedIndex As Integer = -1
        For i = 0 To X.Count - 1
            If TextBox3.Text = "" Then
                MsgBox("Введите искомое значение!")
                Exit Sub
            End If
        If X(i) = CInt(TextBox3.Text) Then
            foundedIndex = i
            MsgBox("Эллемент найден!")
            Exit For
        End If
        If i + i > i * 2 Then
            Label5.Text = "2"
        End If
        Next
        If foundedIndex = -1 Then
            MsgBox("Элемент не найден")
        End If
    End Sub

        Label1.Text = ""
        Dim Mass(10) As Integer
        Dim R As New Random
        For I As Integer = 0 To Mass.Length - 1
            Mass(I) = R.Next(0, 10)
            Label1.Text &= Mass(I) & " "
        Next
        Dim Search As Integer = 2 'У Вас из TextBox
        Dim Count As Integer = 0
 
 
        For Each I As Integer In Mass
            If Search = I Then Count += 1
        Next
        Me.Text = Count

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    Dim str() As String = {"vvv", "ee", "frt", "vvv", "yy", "vvv"}
    Dim srh As String = "vvv"
    Dim ind As Integer = Array.IndexOf(str, srh)
    Dim count As Integer
    If ind >= 0 Then
        count += 1
        Do Until ind < 0
            ind = Array.IndexOf(str, srh, ind + 1)
            count += 1
        Loop
        count -= 1
    End If
    MsgBox(count.ToString)
End Sub

        Dim Str1() As String = TextBox1.Text.Split
        Dim Str2() As String = TextBox2.Text.Split
        Dim T1 As String = String.Join(" ", Str1.Except(Str2).ToArray)
        Dim T2 As String = String.Join(" ", Str2.Except(Str1).ToArray)
        TextBox1.Text = T1
        TextBox2.Text = T2

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        ListBox1.Items.Clear()
        ListBox2.Items.Clear()
        ListBox3.Items.Clear()
 
        Dim kls, dtr, sd As Integer
        Dim j As Integer = -1
        Dim ta1() As String = Split(RichTextBox1.Text, " ")
        Dim ta2() As String = Split(RichTextBox2.Text, " ")
        sd = Math.Abs(ta1.Count - ta2.Count)
        If ta1.Count > ta2.Count Then
            kls = ta2.Count
        Else
            kls = ta1.Count
        End If
       
        For i = 0 To kls - 1
            j = j + 1
            If String.Compare(ta1(i), ta2(j)) = 0 Then
                ListBox1.Items.Add(ta1(i) & "  ta1 " & i)
                ListBox2.Items.Add(ta2(j) & "  ta2 " & j)
            Else
                i = i + 1
                ListBox3.Items.Add(ta1(i))
            End If
        Next
    End Sub

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim searchString As String
        Dim kls As Integer
        Dim ta1() As String = Split(RichTextBox1.Text, " ")
        Dim ta2() As String = Split(RichTextBox2.Text, " ")
        ListBox1.Items.Clear()
        ListBox2.Items.Clear()
        For i = 0 To ta1.Count - 1
            ListBox1.Items.Add(ta1(i))
        Next
        For i = 0 To ta2.Count - 1
            ListBox2.Items.Add(ta2(i))
        Next
        '/  Dim searchString As String = TextBox1.Text
        ' Ensure we have a proper string to search for.
        If ta1.Count > ta2.Count Then
            kls = ta2.Count
        Else
            kls = ta1.Count
        End If
        Dim index As Integer
        Dim textEnd As Integer = RichTextBox1.TextLength
        For i = 0 To kls - 1
            searchString = ListBox2.Items(i)
            If searchString <> String.Empty Then
                ' Find the item in the list and store the index to the item.
                Dim ind As Integer = ListBox1.FindString(searchString)
                ' Determine if a valid index is returned. Select the item if it is valid.
                If ind <> -1 Then
                    ListBox1.SetSelected(ind, True)
                    ListBox1.Items.RemoveAt(ind)
                Else
                    ' MessageBox.Show("The search string did not match any items in the ListBox")
                End If
            End If
        Next
        For i = 0 To ListBox1.Items.Count - 1
            RichTextBox1.Find(ListBox1.Items(i), index, textEnd, RichTextBoxFinds.WholeWord)
            RichTextBox1.SelectionFont = New Font("Verdana", 12, FontStyle.Bold)
            RichTextBox1.SelectionColor = Color.Red
            index = RichTextBox1.Text.IndexOf(ListBox1.Items(i), index) + 1
        Next
    End Sub