DataTable с условием выборки как источник данных для Combobox

    Private Sub TextBox1_Validated(sender As Object, e As EventArgs) Handles TextBox1.Validated
        Dim strSelectText As String = "Pressure_for_search >= " & TextBox1.Text
        ComboBox1.DataSource = Form_Main.TestDataTable.Select(strSelectText)
        ComboBox1.DisplayMember = "Main_tube_type"
    End Sub

dt2.DefaultView.RowFilter = "(Convert([колличество],System.String) >= 16)"
2 dwe.RowFilter = "колличество >= '16'"

Public Class Form1
    Public dt1, dt2 As DataTable
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        dt1 = New DataTable
        dt1.Columns.Add("Продукты")
        dt1.Columns.Add("колличество")
        dt1.Rows.Add(New String() {"Яблоки", "45"})
        dt1.Rows.Add(New String() {"Помидоры", "12"})
        dt1.Rows.Add(New String() {"Тыквы", "25"})
        dt1.Rows.Add(New String() {"кабачки", "34"})
        dt2 = dt1
        DataGridView1.DataSource = dt1
        DataGridView1.Columns(0).Width = 100
        DataGridView1.Columns(1).Width = 100
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim str As String = Nothing
        Dim str1 As String = Nothing
        dt2 = New DataTable
        dt2 = dt1.Copy
        dt2.DefaultView.RowFilter = "(Convert([колличество],System.String) >= 16)"
        For Each r In dt2.Rows
            str += r("Продукты") & vbTab & r("колличество") & vbCrLf
        Next
        MsgBox(str)
        ComboBox1.DataSource = dt2
        ComboBox1.DisplayMember = "колличество"
        Dim dwe As DataView
        dwe = New DataView(dt2)
        dwe.RowFilter = "колличество >= '16'"
        For Each r1 In dwe
            str1 += r1("Продукты") & vbTab & r1("колличество") & vbCrLf
        Next
        MsgBox(str1)
        DataGridView2.DataSource = dt2
        DataGridView2.Columns(0).Width = 100
        DataGridView2.Columns(1).Width = 100
        ComboBox2.DataSource = dwe
        ComboBox2.DisplayMember = "колличество"
        DataGridView3.DataSource = dwe
        DataGridView3.Columns(0).Width = 100
        DataGridView3.Columns(1).Width = 100
    End Sub
End Class

Public Class Form1
    Public dt1, dt2, dt3 As DataTable
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        dt1 = New DataTable
        dt1.Columns.Add("Продукты")
        dt1.Columns.Add("колличество")
        dt1.Rows.Add(New String() {"Яблоки", "45"})
        dt1.Rows.Add(New String() {"Помидоры", "12"})
        dt1.Rows.Add(New String() {"Тыквы", "25"})
        dt1.Rows.Add(New String() {"кабачки", "34"})
        dt2 = dt1
        DataGridView1.DataSource = dt1
        DataGridView1.Columns(0).Width = 100
        DataGridView1.Columns(1).Width = 100
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim str As String = Nothing
        Dim str1 As String = Nothing
        dt2 = New DataTable
        dt2 = dt1.Copy
        dt3 = New DataTable
        dt3 = dt1.Copy
        dt2.DefaultView.RowFilter = "(Convert([колличество],System.String) >= 16)"
        For Each r In dt2.Rows
            str += r("Продукты") & vbTab & r("колличество") & vbCrLf
        Next
        MsgBox(str)
        ComboBox1.DataSource = dt2
        ComboBox1.DisplayMember = "колличество"
        Dim dwe As DataView
        dwe = New DataView(dt3)
        dwe.RowFilter = "колличество >= '16'"
        For Each r1 In dwe
            str1 += r1("Продукты") & vbTab & r1("колличество") & vbCrLf
        Next
        MsgBox(str1)
        DataGridView2.DataSource = dt3
        DataGridView2.Columns(0).Width = 100
        DataGridView2.Columns(1).Width = 100
        ComboBox2.DataSource = dwe
        ComboBox2.DisplayMember = "колличество"
        DataGridView3.DataSource = dwe
        DataGridView3.Columns(0).Width = 100
        DataGridView3.Columns(1).Width = 100
    End Sub
End Class

    Sub FillCB()
        If TextBox1.Text <> "" Then
            Dim DataTableTest As New Data.DataTable
            DataTableTest = Form_Main.DTCombobox40
            Dim strSelectComand As String = "Pressure_for_search >= " & TextBox1.Text
            DataTableTest.DefaultView.RowFilter = "(Convert([Main_tube_material],System.String) Like '" & Form_Main.ComboBox33.Text & "' 
            AND Convert([Pressure_for_search],System.String) >= " & intPressureSearch & "
            And Convert([Temperature_for_search],System.String) >= " & intTemperatureSearch & "
            And Convert([Main_tube],System.String) LIKE '" & Form_Main.type & "'
            And Convert([Work_line],System.String) LIKE 'yes')"
            DataTableTest = DataTableTest.DefaultView.ToTable
            ComboBox1.DataSource = DataTableTest
            ComboBox1.DisplayMember = "Main_tube_type"
        End If
    End Sub

Private Function CropeArr(ByVal Arr As System.Data.DataTable) As System.Data.DataTable
        Dim dt As New System.Data.DataTable
        Dim columns() As DataColumn = {New DataColumn("Names"), New DataColumn(Arr.Columns.Item(1).ColumnName)}
        dt.Columns.AddRange(columns)
        dt.TableName = Arr.TableName
        Dim keys(1) As DataColumn
        keys(0) = dt.Columns("Names")
        dt.PrimaryKey = keys
        Dim rw As System.Data.DataRow
 
        For w = 0 To Arr.Rows.Count - 1
            Try
                rw = dt.NewRow()
                rw!Names = Arr.Rows(w)!Names
                rw.Item(1) = Arr.Rows(w).Item(1)
                dt.Rows.Add(rw)
            Catch ex As ConstraintException 'Играет роль хеш-функции
            End Try
        Next
        Return dt
    End Function

Dim hash As New HashSet(Of String)
For Each s In (From r In DataTableTest.Rows Select r.Item("Main_tube_type")).ToList
    hash.Add(s)
Next
ComboBox1.DataSource = hash.ToList

Dim dblPressureSearch As Double
            If Me.TextBox7.Text = Nothing Then
                dblPressureSearch = 0
            Else
                dblPressureSearch = Me.TextBox7.Text
            End If
            ' Копия DataTable для фильтра и устранения повторений.
            Dim DataTableTest As New Data.DataTable
            DataTableTest = Me.DTCombobox6_1
            ' Запрос в DataTable с фильтром. Отбор значений по параметрам.
            DataTableTest.DefaultView.RowFilter = "(Convert([Pressure_for_search],System.String) >= " & dblPressureSearch & ")"
            DataTableTest = DataTableTest.DefaultView.ToTable
            If DataTableTest.Rows.Count <> 0 Then
                Me.ComboBox6.DataSource = DataTableTest
                Me.ComboBox6.DisplayMember = "Flange_pressure_rating_type"
            Else
                Me.ComboBox6.DataSource = Nothing
                Me.ComboBox6.Items.Clear()
                Me.ComboBox6.Items.Add("нет")
                Me.ComboBox6.SelectedIndex = 0
                Me.key4_6 = "?"
            End If

            Dim dblPressureSearch As Double
            If Me.TextBox7.Text = Nothing Then
                dblPressureSearch = 0
            Else
                dblPressureSearch = Me.TextBox7.Text
            End If
            ' Копия DataTable для фильтра и устранения повторений.
            Dim DataTableTest As New Data.DataTable
            DataTableTest = Me.DTCombobox6_1
            ' Запрос в DataTable с фильтром. Отбор значений по параметрам.
            DataTableTest.DefaultView.RowFilter = "(Convert([Pressure_for_search],System.String) >= " & dblPressureSearch.ToString.Replace(",", ".") & ")"
            DataTableTest = DataTableTest.DefaultView.ToTable
            If DataTableTest.Rows.Count <> 0 Then
                Me.ComboBox6.DataSource = DataTableTest
                Me.ComboBox6.DisplayMember = "Flange_pressure_rating_type"
            Else
                Me.ComboBox6.DataSource = Nothing
                Me.ComboBox6.Items.Clear()
                Me.ComboBox6.Items.Add("нет")
                Me.ComboBox6.SelectedIndex = 0
                Me.key4_6 = "?"
            End If

DataTableTest.DefaultView.RowFilter = "(Convert([кол_во],System.String) >= " & dblPressureSearch.ToString.Replace(",", ".") & ")"

Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
        Dim dblPressureSearch As Double
        If TextBox6.Text = Nothing Then
            dblPressureSearch = 0
        Else
            dblPressureSearch = TextBox6.Text
        End If
        ' Копия DataTable для фильтра и устранения повторений.
        Dim DataTableTest As New Data.DataTable
        DataTableTest = dt1
        ' Запрос в DataTable с фильтром. Отбор значений по параметрам.
        DataTableTest.DefaultView.RowFilter = "(Convert([кол_во],System.String) >= " & dblPressureSearch.ToString.Replace(",", ".") & ")"
        DataTableTest = DataTableTest.DefaultView.ToTable
        DataGridView2.DataSource = DataTableTest
        DataGridView1.Columns(0).Width = 100
        DataGridView1.Columns(1).Width = 100
    End Sub

DataTableTest.DefaultView.RowFilter = "'" & System.Convert.ToString("[кол_во]") & "' >= '" & dblPressureSearch.ToString.Replace(",", ".") & "' "

DataTableTest.DefaultView.RowFilter = "[кол_во] >= "& Replace(dblPressureSearch,",", ".") &" "