自定义控件之DataGridView列（日期时间选择列）

效果图如下：


代码如下：

Imports System
Imports System.Windows.Forms

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)
            If Not (value Is 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()
        Me.Style.Format = "d"
    End Sub

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

        Dim ctl As CalendarEditingControl = CType(DataGridView.EditingControl, CalendarEditingControl)
        ctl.Text = CType(Me.Value, String)
    End Sub

    Public Overrides ReadOnly Property EditType() As Type
        Get
            Return GetType(CalendarEditingControl)
        End Get
    End Property

    Public Overrides ReadOnly Property ValueType() As Type
        Get
            Return GetType(DateTime)
        End Get
    End Property

    Public Overrides ReadOnly Property DefaultNewRowValue() As Object
        Get
            Return DateTime.Now
        End Get
    End Property

End Class

Class CalendarEditingControl
    Inherits DateTimePicker
    Implements IDataGridViewEditingControl

    Private dataGridView As DataGridView
    Private Shadows ValueChanged As Boolean = False
    Private rowIndexNum As Integer

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

    Protected Overrides Sub OnValueChanged(ByVal eventargs As System.EventArgs)
        MyBase.OnValueChanged(eventargs)
        Call NotifyDataGridViewOfValueChange()
    End Sub

    Private Sub NotifyDataGridViewOfValueChange()
        valueChanged = True
        DataGridView.NotifyCurrentCellDirty(True)
    End Sub

    Public Property EditingControlFormattedValue() As Object Implements IDataGridViewEditingControl.EditingControlFormattedValue
        Get
            Return Me.Text
        End Get
        Set(ByVal value As Object)
            Me.Text = value.ToString
            Call NotifyDataGridViewOfValueChange()
        End Set
    End Property

    Public Function GetEditingControlFormattedValue(ByVal context As DataGridViewDataErrorContexts) As Object Implements IDataGridViewEditingControl.GetEditingControlFormattedValue
        Return Me.Text
    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 False
        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 dataGridView
        End Get
        Set(ByVal value As DataGridView)
            dataGridView = value
        End Set
    End Property

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

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


End Class