Datagrid 中的 DateTimePicker - 清楚它的价值？

Question

我使用了 MSDN 站点的代码，在 Datagrid 中添加了 DateTimePicker。我把它缩短了一点，所以现在 DateTimepicker 不显示它的默认值，只有当用户从它中选择值时才会进入列。现在我想添加用于使用 Delete 或 Backspace 键清除 DTP 的代码。我知道 DTP 不能有空值，但我已经设法用其他 DTP（不在 Datagridview 内）做到这一点，如下所示：

 Private Sub DataGridView1_KeyDown(sender As Object, e As KeyEventArgs) Handles DataGridView1.KeyDown

        If e.KeyCode = Keys.Delete Or e.KeyCode = Keys.Back Then
            DTPtest.format = DTPtest.custom
            DTPtest.Format = DateTimePickerFormat.Custom
            DTPtest.CustomFormat = " "
        End If
    End Sub

在 Datagrid 中托管 DateTimePicker 的代码超出了我的知识范围，我不知道我应该在哪里创建类似的东西来工作。非常感谢任何帮助!!!

这是我用于托管 DaTeTimePicker 的代码（如前所述，来自 MSDN）：

Public Class CalendarColumn
    Inherits DataGridViewColumn

    Public Sub New()
        MyBase.New(New CalendarCell())
    End Sub

    Public Overrides Property CellTemplate() As DataGridViewCell
        Get
            Return MyBase.CellTemplate
        End Get
        Set(ByVal value As DataGridViewCell)

            ' Ensure that the cell used for the template is a CalendarCell.
            If (value IsNot Nothing) AndAlso
                Not value.GetType().IsAssignableFrom(GetType(CalendarCell)) _
                Then
                Throw New InvalidCastException("Must be a CalendarCell")
            End If
            MyBase.CellTemplate = value

        End Set
    End Property

End Class

Public Class CalendarCell
    Inherits DataGridViewTextBoxCell

    Public Sub New()
        ' Use the short date format.
        Me.Style.Format = "d"
    End Sub

    Public Overrides Sub InitializeEditingControl(ByVal rowIndex As Integer,
        ByVal initialFormattedValue As Object,
        ByVal dataGridViewCellStyle As DataGridViewCellStyle)

        ' Set the value of the editing control to the current cell value.
        MyBase.InitializeEditingControl(rowIndex, initialFormattedValue,
            dataGridViewCellStyle)

        Dim ctl As CalendarEditingControl =
            CType(DataGridView.EditingControl, CalendarEditingControl)

    End Sub

    Public Overrides ReadOnly Property EditType() As Type
        Get
            ' Return the type of the editing control that CalendarCell uses.
            Return GetType(CalendarEditingControl)
        End Get
    End Property

    Public Overrides ReadOnly Property ValueType() As Type
        Get
            ' Return the type of the value that CalendarCell contains.
            Return GetType(DateTime)

        End Get

    End Property

End Class

Class CalendarEditingControl
    Inherits DateTimePicker
    Implements IDataGridViewEditingControl

    Private dataGridViewControl As DataGridView
    Private valueIsChanged As Boolean = False
    Private rowIndexNum As Integer

    Public Sub New()
        Me.Format = DateTimePickerFormat.Short
    End Sub

    Public Property EditingControlFormattedValue() As Object _
        Implements IDataGridViewEditingControl.EditingControlFormattedValue

        Get
            Return Me.Value.ToShortDateString()
        End Get

        Set(ByVal value As Object)
            Try
                ' This will throw an exception of the string is 
                ' null, empty, or not in the format of a date.
                Me.Value = DateTime.Parse(CStr(value))
            Catch
                ' In the case of an exception, just use the default
                ' value so we're not left with a null value.
                Me.Value = DateTime.Now
            End Try
        End Set

    End Property

    Public Function GetEditingControlFormattedValue(ByVal context _
        As DataGridViewDataErrorContexts) As Object _
        Implements IDataGridViewEditingControl.GetEditingControlFormattedValue

        Return Me.Value.ToShortDateString()

    End Function

    Public Sub ApplyCellStyleToEditingControl(ByVal dataGridViewCellStyle As _
        DataGridViewCellStyle) _
        Implements IDataGridViewEditingControl.ApplyCellStyleToEditingControl

        Me.Font = dataGridViewCellStyle.Font
        Me.CalendarForeColor = dataGridViewCellStyle.ForeColor
        Me.CalendarMonthBackground = dataGridViewCellStyle.BackColor

    End Sub

    Public Property EditingControlRowIndex() As Integer _
        Implements IDataGridViewEditingControl.EditingControlRowIndex

        Get
            Return rowIndexNum
        End Get
        Set(ByVal value As Integer)
            rowIndexNum = value
        End Set

    End Property

    Public Function EditingControlWantsInputKey(ByVal key As Keys,
        ByVal dataGridViewWantsInputKey As Boolean) As Boolean _
        Implements IDataGridViewEditingControl.EditingControlWantsInputKey

        ' Let the DateTimePicker handle the keys listed.
        Select Case key And Keys.KeyCode
            Case Keys.Left, Keys.Up, Keys.Down, Keys.Right,
                Keys.Home, Keys.End, Keys.PageDown, Keys.PageUp

                Return True

            Case Else
                Return Not dataGridViewWantsInputKey
        End Select

    End Function

    Public Sub PrepareEditingControlForEdit(ByVal selectAll As Boolean) _
        Implements IDataGridViewEditingControl.PrepareEditingControlForEdit

        ' No preparation needs to be done.

    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 dataGridViewControl
        End Get
        Set(ByVal value As DataGridView)
            dataGridViewControl = value
        End Set

    End Property

    Public Property EditingControlValueChanged() As Boolean _
        Implements IDataGridViewEditingControl.EditingControlValueChanged

        Get
            Return valueIsChanged
        End Get
        Set(ByVal value As Boolean)
            valueIsChanged = value
        End Set

    End Property

    Public ReadOnly Property EditingControlCursor() As Cursor _
        Implements IDataGridViewEditingControl.EditingPanelCursor

        Get
            Return MyBase.Cursor
        End Get

    End Property

    Protected Overrides Sub OnValueChanged(ByVal eventargs As EventArgs)

        ' Notify the DataGridView that the contents of the cell have changed.
        valueIsChanged = True
        Me.EditingControlDataGridView.NotifyCurrentCellDirty(True)
        MyBase.OnValueChanged(eventargs)

    End Sub

End Class

Answer 1

解决了，其实很简单：

Private Sub DataGridView1_KeyDown(sender As Object, e As KeyEventArgs) Handles DataGridView1.KeyDown

        If e.KeyCode = Keys.Delete Or e.KeyCode = Keys.Back Then
            DataGridView1.CurrentCell.Value = Nothing
        End If

    End Sub

唯一不同的是你必须离开单元格，然后 return 进入单元格才能删除。

Datagrid 中的 DateTimePicker - 清楚它的价值？

DateTimePicker in Datagrid - clear It's value?

vb.net

datagrid

datagridview

datetimepicker