在 WinForm 的 DataGridView 中使用 DateTimePicker

在 WinForm 的 DataGridView 想要使用日期格式
但是在加入資料行時卻沒有相關型別可以使用
只好用 DataGridViewTextBoxColumn 來湊合著用
怕使用者若亂輸入非日期格式只好多寫點程式來檢查
難道沒有更好的方式?

答案就是自訂一個型別為 DateTimePicker 的 DataGridViewColumn
如下圖，是否跟你 DataGridView 所能增加控制項的數量不一樣? ##CONTINUE##

其做法如下
1. 繼承 DateTimePicker 並實作 IDataGridViewEditingControl
2. 繼承 DataGridViewTextBoxCell 來自訂 DataGridView 的 Cell，並把自訂的 DateTimePicker 放進 Cell
3. 繼承 DataGridViewColumn 來自訂 DataGridView 的 Column，並把自訂的 Cell 放進 Column

Public Class DataGridViewCalendarEditingControl
    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)
            If TypeOf value Is [String] Then
                Me.Value = DateTime.Parse(CStr(value))
            End If
        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

        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
    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)
        valueIsChanged = True
        Me.EditingControlDataGridView.NotifyCurrentCellDirty(True)
        MyBase.OnValueChanged(eventargs)
    End Sub
End Class

Public Class DataGridViewCalendarCell
    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 DataGridViewCalendarEditingControl = _
            CType(DataGridView.EditingControl, DataGridViewCalendarEditingControl)
        If Not Me.Value Is Nothing Then
            ctl.Value = CType(Me.Value, DateTime)
        End If
    End Sub

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

Public Class DataGridViewCalendarColumn
    Inherits DataGridViewColumn
    Public Sub New()
        MyBase.New(New DataGridViewCalendarCell())
    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(DataGridViewCalendarCell)) _
                Then
                Throw New InvalidCastException("Must be a CalendarCell")
            End If
            MyBase.CellTemplate = value
        End Set
    End Property
End Class

應用的情況如下圖