1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
 

Public Class ControlLink
    Inherits LinkLabel

    Private _Link As Control

    <System.ComponentModel.Category("My Properties")>
    Public Property LinkedControl As Control ' Μπορείς να το περιορίσεις γία combos μόνο. (as ComboBox)
        Get
            Return Me._Link
        End Get
        Set(ByVal value As Control)
            If TypeOf value Is Form Then
                If Me.DesignMode Then
                    Throw New Exception("Όχι φόρμα.")
                Else
                    Throw New Exception("Run time exception. Όχι φόρμα.")
                End If
            ElseIf Object.ReferenceEquals(Me, value) Then
                Throw New Exception("Όχι τον εαυτό μου.")
            End If

            Me._Link = value
        End Set
    End Property

    Protected Overrides Sub OnLinkClicked(ByVal e As System.Windows.Forms.LinkLabelLinkClickedEventArgs)
        If TypeOf Me._Link Is ComboBox Then
            Dim cbo = DirectCast(Me._Link, ComboBox)

            If cbo.SelectedIndex = -1 Then
                ' Δείξε φόρμα Καταχώρησης ή όλες τις τιμές σε Grid
            Else
                ' Δείξε φόρμα Ενημέρωσης ή όλες τις τιμές σε Grid
            End If
        End If

        MyBase.OnLinkClicked(e)
    End Sub
End Class

1
2
3
4
5
6
7
8
9
10
11
12
13
14
 

Public Class MyCombo
    Inherits ComboBox

    ' ή static με παράμετρο combo
    Public Sub Fill(ByVal Data As DataTable, ByVal IDColumn As String, ByVal DisplayColumn As String)
        Me.DataSource = Nothing
        Me.Items.Clear()

        Me.ValueMember = IDColumn
        Me.DisplayMember = DisplayColumn

        Me.DataSource = Data
    End Sub
End Class

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
 

Public Class Form1
    ' Αυτο το datatable είναι (και καλα) ο πίνακας της βάσης με τα δεδομένα
    Private _Data As DataTable

    ' να μπορεί ο χρήστης να κάνει γράφει κάτι και να πατάει enter σε πολλές εγγραφές
    Private Sub MyCombo1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles MyCombo1.KeyPress
        If e.KeyChar <> ChrW(Keys.Return) Then Return

        If Me.MyCombo1.Text <> String.Empty Then
            Dim rows() As DataRow
            Dim mydataset As New DataSet

            rows = _Data.Select("Description LIKE '%" & CType(sender, ComboBox).Text & "%'")

            If rows.Length > 0 Then
                mydataset.Merge(rows)
                MyCombo1.Fill(mydataset.Tables(0), "ID", "Description")
            Else
                MyCombo1.Fill(Me._Data.Clone, "ID", "Description")
                MessageBox.Show("Δεν βρήκα εγγραφές")
            End If
        Else
            MyCombo1.Fill(_Data, "ID", "Description")
        End If
    End Sub


    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim r As DataRow
        Dim dt As New DataTable

        dt.Columns.Add("ID", GetType(Integer))
        dt.Columns(0).AllowDBNull = False
        dt.Columns(0).Unique = True
        dt.Columns(0).AutoIncrement = True
        dt.Columns(0).AutoIncrementSeed = 1
        dt.Columns(0).AutoIncrementStep = 1

        dt.Columns.Add("Description")

        For i As Integer = 0 To 255
            r = dt.NewRow

            r.Item("Description") = Chr(i)
            dt.Rows.Add(r)
        Next

        dt.AcceptChanges()

        Me._Data = dt

        MyCombo1.Fill(dt, "ID", "Description")
    End Sub
End Class