Public Class DataGridViewHexTextboxCell
Inherits DataGridViewTextBoxCell

Public Sub New()
Me.Style.Format = "".PadLeft(Me.MaxInputLength, "0"c) 'dieses Datenformat verwenden...
End Sub

''' <summary>
''' den String des Editing-Controls auf den aktuellen Zellwert einstellen...
''' </summary>
Public Overrides Sub InitializeEditingControl(ByVal rowIndex As Integer, ByVal initialFormattedValue As Object, ByVal dataGridViewCellStyle As DataGridViewCellStyle)
MyBase.InitializeEditingControl(rowIndex, initialFormattedValue, dataGridViewCellStyle)
Dim _EditingControl = CType(DataGridView.EditingControl, DataGridViewHexTextboxEditingControl)
Me.MaxInputLength = DirectCast(DataGridView.Columns(DataGridView.CurrentCell.ColumnIndex), DataGridViewHexTextboxColumn).HexFieldLength
If Convert.IsDBNull(Me.Value) Then
_EditingControl.Text = "".PadLeft(Me.MaxInputLength, "0"c)
Else
_EditingControl.Text = Me.Value.ToString
End If
End Sub
''' <summary>
''' den Typ des DataGridViewHexTextboxCell zurückgeben...
''' </summary>
''' <returns></returns>
Public Overrides ReadOnly Property EditType() As Type
Get
Return GetType(DataGridViewHexTextboxEditingControl)
End Get
End Property
''' <summary>
''' den Datentyp von DataGridViewHexTextboxCell zurückgeben...
''' </summary>
Public Overrides ReadOnly Property ValueType() As Type
Get
Return GetType(String)
End Get
End Property
''' <summary>
''' Vorschlagswert bei erstellter neuen Zeile definieren...
''' </summary>
Public Overrides ReadOnly Property DefaultNewRowValue() As Object
Get
Return ""
End Get
End Property
End Class

Class DataGridViewHexTextboxEditingControl
Inherits TextBox
Implements IDataGridViewEditingControl

Private _DataGridViev As DataGridView
Private _IsValueChanged As Boolean = False
Private _RowIndex As Integer
Private _MaxFieldLength As Integer

Public Sub New()
'das Editcontrol voreinstellen...
End Sub

Public Property EditingControlFormattedValue() As Object Implements IDataGridViewEditingControl.EditingControlFormattedValue
Get
Return Me.Text
End Get
Set(ByVal value As Object)
If TypeOf value Is String Then
Me.Text = value.ToString
End If
End Set
End Property

'''' <summary>
'''' alle Textbox-Eingaben auf Großbuchstaben und definierter Feldlänge umformen
'''' </summary>
Public Function GetEditingControlFormattedValue(ByVal context As DataGridViewDataErrorContexts) As Object Implements IDataGridViewEditingControl.GetEditingControlFormattedValue
Return Me.Text.ToUpper.PadLeft(_MaxFieldLength, "0"c)
End Function

Public Sub ApplyCellStyleToEditingControl(ByVal dataGridViewCellStyle As DataGridViewCellStyle) Implements IDataGridViewEditingControl.ApplyCellStyleToEditingControl
Me.Font = dataGridViewCellStyle.Font
Me.ForeColor = dataGridViewCellStyle.ForeColor
Me.BackColor = dataGridViewCellStyle.BackColor
End Sub

Public Property EditingControlRowIndex() As Integer Implements IDataGridViewEditingControl.EditingControlRowIndex
Get
Return _RowIndex
End Get
Set(ByVal value As Integer)
_RowIndex = value
End Set
End Property

''' <summary>
''' bestimmte Tastencodes zulassen
''' </summary>
Public Function EditingControlWantsInputKey(ByVal key As Keys, ByVal dataGridViewWantsInputKey As Boolean) As Boolean Implements IDataGridViewEditingControl.EditingControlWantsInputKey
Select Case key And Keys.KeyCode
Case Keys.Left, Keys.Right, Keys.Home, Keys.End, Keys.Back, Keys.Delete
Return True
Case Else
Return False
End Select
End Function

Public Sub PrepareEditingControlForEdit(ByVal selectAll As Boolean) Implements IDataGridViewEditingControl.PrepareEditingControlForEdit
_MaxFieldLength = DirectCast(_DataGridViev(_DataGridViev.CurrentCell.ColumnIndex, _RowIndex), DataGridViewHexTextboxCell).MaxInputLength
End Sub

Public ReadOnly Property RepositionEditingControlOnValueChange() As Boolean Implements IDataGridViewEditingControl.RepositionEditingControlOnValueChange
Get
Return False
End Get
End Property

Public Property EditingControlDataGridView() As DataGridView Implements IDataGridViewEditingControl.EditingControlDataGridView
Get
Return _DataGridViev
End Get
Set(ByVal value As DataGridView)
_DataGridViev = value
End Set
End Property

Public Property EditingControlValueChanged() As Boolean Implements IDataGridViewEditingControl.EditingControlValueChanged
Get
Return _IsValueChanged
End Get
Set(ByVal value As Boolean)
_IsValueChanged = value
End Set
End Property

Public ReadOnly Property EditingControlCursor() As Cursor Implements IDataGridViewEditingControl.EditingPanelCursor
Get
Return MyBase.Cursor
End Get
End Property

''' <summary>
''' das DataGridView benachrichtigen, wenn sich sich der Inhalt der Zelle geändert hat...
''' </summary>
Protected Overrides Sub OnTextChanged(ByVal e As EventArgs)
_IsValueChanged = True
Me.EditingControlDataGridView.NotifyCurrentCellDirty(True)
MyBase.OnTextChanged(e)
End Sub

''' <summary>
''' Eingabe auf erlaubte Zeichen prüfen
''' </summary>
Protected Overrides Sub OnKeyPress(e As KeyPressEventArgs)
If e.KeyChar <> Microsoft.VisualBasic.ControlChars.Back Then
e.Handled = Not Uri.IsHexDigit(e.KeyChar)
End If
End Sub
End Class