我正在创建一个托管datagridviewcell控件的numeric updown。除了一件事，一切都很顺利。我无法在textboxcell或comboboxcell之类的转义按键上恢复更改。我的datagridviewcell是基于this示例创建的。所以任何人都知道如何在转义键按下时将numeric updown cell还原为先前的值？
NumericColumn类：
Imports System
Imports System.Windows.Forms
Public Class NumericColumn
Inherits DataGridViewColumn
''' <summary>
''' Get, set numeric control min value
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property MinValue() As Decimal
Get
Return CType(MyBase.CellTemplate, NumericCell).MinValue
End Get
Set(ByVal value As Decimal)
CType(MyBase.CellTemplate, NumericCell).MinValue = value
End Set
End Property
''' <summary>
''' Get, set numeric control max value
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property MaxValue() As Decimal
Get
Return CType(MyBase.CellTemplate, NumericCell).MaxValue
End Get
Set(ByVal value As Decimal)
CType(MyBase.CellTemplate, NumericCell).MaxValue = value
End Set
End Property
''' <summary>
''' Get, set numeric control value
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property NumericControlValue() As Decimal
Get
Return CType(MyBase.CellTemplate, NumericCell).NumericControlValue
End Get
Set(ByVal value As Decimal)
CType(MyBase.CellTemplate, NumericCell).NumericControlValue = value
End Set
End Property
''' <summary>
''' Indicate number of decimal places to display
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property DecimalPlaces() As Integer
Get
Return CType(MyBase.CellTemplate, NumericCell).DecimalPlaces
End Get
Set(ByVal value As Integer)
CType(MyBase.CellTemplate, NumericCell).DecimalPlaces = value
End Set
End Property
''' <summary>
''' Detemine the value to increment or decrement each time button click
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property Increment() As Integer
Get
Return CType(MyBase.CellTemplate, NumericCell).Increment
End Get
Set(ByVal value As Integer)
CType(MyBase.CellTemplate, NumericCell).Increment = value
End Set
End Property
Public Sub New()
MyBase.New(New NumericCell())
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(NumericCell)) _
Then
Throw New InvalidCastException("Must be a Numeric Cell")
End If
MyBase.CellTemplate = value
End Set
End Property
''' <summary>
''' Override clone method to clone new added properties
''' </summary>
''' <returns></returns>
''' <remarks></remarks>
Public Overrides Function Clone() As Object
Dim obj As NumericColumn = MyBase.Clone()
obj.MaxValue = Me.MaxValue
obj.MinValue = Me.MinValue
obj.NumericControlValue = Me.NumericControlValue
obj.DecimalPlaces = Me.DecimalPlaces
obj.Increment = Me.Increment
Return obj
End Function
End Class
NumericCell类
Imports System
Imports System.Windows.Forms
Public Class NumericCell
Inherits DataGridViewTextBoxCell
''' <summary>
''' Min value for numeric control
''' </summary>
''' <remarks></remarks>
Private min As Decimal = 0.0
''' <summary>
''' Max value for numeric control
''' </summary>
''' <remarks></remarks>
Private max As Decimal = 100.0
''' <summary>
''' Value for numeric control
''' </summary>
''' <remarks></remarks>
Private controlValue As Decimal = 0.0
''' <summary>
''' Decimal places for numeric control
''' </summary>
''' <remarks></remarks>
Private places As Integer = 0
''' <summary>
''' Detemine the value to increment or decrement each time button click
''' </summary>
''' <remarks></remarks>
Private incrementStep As Integer = 1
''' <summary>
''' Get, set numeric control min value
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property MinValue() As Decimal
Get
Return Me.min
End Get
Set(ByVal value As Decimal)
Me.min = value
End Set
End Property
''' <summary>
''' Get, set numeric control max value
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property MaxValue() As Decimal
Get
Return Me.max
End Get
Set(ByVal value As Decimal)
Me.max = value
End Set
End Property
''' <summary>
''' Get, set numeric control value
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property NumericControlValue() As Decimal
Get
Return Me.controlValue
End Get
Set(ByVal value As Decimal)
Me.controlValue = value
End Set
End Property
''' <summary>
''' Indicate number of decimal places to display
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property DecimalPlaces() As Integer
Get
Return Me.places
End Get
Set(ByVal value As Integer)
Me.places = value
End Set
End Property
''' <summary>
''' Detemine the value to increment or decrement each time button click
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property Increment() As Integer
Get
Return Me.incrementStep
End Get
Set(ByVal value As Integer)
Me.incrementStep = value
End Set
End Property
Public Sub New()
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 NumericEditingControl = CType(DataGridView.EditingControl, NumericEditingControl)
RemoveHandler ctl.Enter, AddressOf Me.OnNumericEnter
AddHandler ctl.Enter, AddressOf Me.OnNumericEnter
'config property for control
ctl.Minimum = Me.min
ctl.Maximum = Me.max
ctl.DecimalPlaces = Me.DecimalPlaces
ctl.Increment = Me.incrementStep
ctl.TextAlign = HorizontalAlignment.Right
ctl.ThousandsSeparator = True
' Use the default row value when Value property is null.
If (Me.Value Is Nothing) Then
ctl.Value = Me.controlValue
Else
ctl.Value = CType(Me.Value, Decimal)
End If
End Sub
''' <summary>
''' Handle on enter event of numeric
''' </summary>
''' <param name="sender"></param>
''' <param name="e"></param>
''' <remarks></remarks>
Private Sub OnNumericEnter(ByVal sender As Object, ByVal e As EventArgs)
Dim control As NumericEditingControl = CType(sender, NumericEditingControl)
Dim strValue As String = control.Value.ToString("N2")
control.Select(0, strValue.Length)
End Sub
Public Overrides ReadOnly Property EditType() As Type
Get
' Return the type of the editing control that CalendarCell uses.
Return GetType(NumericEditingControl)
End Get
End Property
Public Overrides ReadOnly Property ValueType() As Type
Get
' Return the type of the value that CalendarCell contains.
Return GetType(String)
End Get
End Property
Public Overrides ReadOnly Property DefaultNewRowValue() As Object
Get
' Use the current date and time as the default value.
Return 0.0
End Get
End Property
''' <summary>
''' Override clone method to clone new added properties
''' </summary>
''' <returns></returns>
''' <remarks></remarks>
Public Overrides Function Clone() As Object
Dim obj As NumericCell = MyBase.Clone()
obj.MaxValue = Me.MaxValue
obj.MinValue = Me.MinValue
obj.NumericControlValue = Me.NumericControlValue
obj.DecimalPlaces = Me.DecimalPlaces
obj.Increment = Me.Increment
Return obj
End Function
End Class
NumericEditingControl类：
Imports System
Imports System.Windows.Forms
Public Class NumericEditingControl
Inherits NumericUpDown
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.ToString("N2")
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 = Decimal.Parse(value)
Catch
' In the case of an exception, just use the default
' value so we're not left with a null value.
Me.Value = 0.0
End Try
End Set
End Property
Public Function GetEditingControlFormattedValue(ByVal context _
As DataGridViewDataErrorContexts) As Object _
Implements IDataGridViewEditingControl.GetEditingControlFormattedValue
Return Me.Value.ToString("N2")
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 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
If key.KeyCode = Keys.Escape Then
End If
Return True
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
答案 0 :(得分：1)
负责处理此行为的部分是EditingControlWantsInputKey。通过查看original code，很明显必须将此部分默认设置为false（=返回先前存储的值），但在您的代码中将其设置为true。这个想法只是为（“特殊”）键设置为true，这不应该引起值的删除;也就是说，你不需要在这里提到scape，只需要任何其他键（触发此函数），你不想激发回到前一个值的行为。
因此，解决方案：
Public Function EditingControlWantsInputKey(ByVal key As Keys, _
ByVal dataGridViewWantsInputKey As Boolean) As Boolean _
Implements IDataGridViewEditingControl.EditingControlWantsInputKey
Return False
End Function