Change date in calendar column to reflect date in combo box

Question

I have a calendar column which is generated on from load. Its value is assigned to todays date - for instance 04/04/2012

I also have a comboBox with a list of months.

Is there a way I can change the value of my calendar column to reflect the chosen month?

For example, if I select January from my comboBox then have the date as 01/01/2012.

        ComboBox1.SelectedIndex = -1
        col = New CalendarColumn
        Me.dataGridView1.Columns.Add(col)
        Me.dataGridView1.Name = "Trip Date"
        Me.dataGridView1.RowCount = 1
        Dim row As DataGridViewRow
        For Each row In Me.dataGridView1.Rows
            row.Cells(0).Value = DateTime.Now
        Next row
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)
            ' Use the default row value when Value property is null.
            If (Me.Value Is Nothing) Then
                ctl.Value = CType(Me.DefaultNewRowValue, DateTime)
            Else
                ctl.Value = CType(Me.Value, DateTime)
            End If
        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
        Public Overrides ReadOnly Property DefaultNewRowValue() As Object
            Get
                ' Use the current date and time as the default value.
                Return DateTime.Now
            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

Hi brianm888,

Welcome to the MSDN forum.

According to your code, it seems that you customer a calendar column to datagridview. I’m afraid that more information will be needed to solve your issue.

I just confused by where is the combobox, a combobox column in datagridview or just a combobox control. If just a combobox control, which calendar cell will be influenced by it, the select one or all calendar cells in the column?  

I assume you use a combobox to manage the data to one of the calendar cell (the cell is selected or the record is select). You can use the ComboBox.SelectedIndexChanged Event of combobox to get the selected item and make the special datetime with the select item, and send the datetime to the selected calendar cell.

Hope this helps.

---

Mark Liu-lxf [MSFT]
MSDN Community Support | Feedback to us

Answer 2

Hi brianm888,

We haven’t heard from you for several days. I’d like to mark my reply as answer firstly. If you have any additional questions, you also can unmark the replay and post your question here. 

Sorry for any inconvenience and have a nice day.

---

Mark Liu-lxf [MSFT]
MSDN Community Support | Feedback to us

Answer 3

Thanks Mark,

Apologies for not updated the thread. I'm still stuck on this problem.

I have a DataGridView with a comboBox Calendar Column.

[quote]

I assume you use a combobox to manage the data to one of the calendar cell (the cell is selected or the record is select). You can use the ComboBox.SelectedIndexChanged Event of combobox to get the selected item and make the special datetime with the select item, and send the datetime to the selected calendar cell.

[/quote]

Can you expand on this further if you get a chance? Ive tried to amend my code (see below) but Im clearly doing something wrong. I have an ComboBox (cmb1) which is outside the DataGridView as well as the ComboBox Calendar Column (cmbCalendar).

Im trying to assign the date in the external ComboBox(cmd1) to the Calendar Cell(cmdCalendar), only if the user selects a value from that comboBox(cmd1) ELSE keep the date.

Hope that makes sense. The error im receiving is "Reference to a non shared member requires an object reference".

Here's the code

 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.
                    If ComboBox1.selectedindex = -1 Then
                        Me.Value = DateTime.Now
                    Else
                        Me.Value = ComboBox1.SelectedValue
                    End If
                End Try
            End Set
        End Property

Answer 4

Hi brianm888,

I think the error message have less relationship with the issue in this thread.

Please check the official article about Reference to a non-shared member requires an object reference: http://msdn.microsoft.com/en-us/library/zwwhc0d0(v=vs.90).aspx

You have referenced a non-shared member within your code and failed to supply an object reference. You cannot use the class name itself to qualify a member that is not shared. The instance must first be declared as an object variable and then referenced by the variable name.

As for your code, I’m afraid that you can’t add the If statement in the property. You need to add the code about changing the date to the ComboBox.SelectedIndexChanged Event as I mentioned. In this way, when the items of combobox changed, the select data in datagridview will be changed. There also has the sample about how to use ComboBox.SelectedIndexChanged Event in the link.

Hope this helps.

---

Mark Liu-lxf [MSFT]
MSDN Community Support | Feedback to us

Answer 5

Hi Mark,

Thank you very much for your help and links. I used the below piece of code and it works ok.

Basically I concatenated my month and year values and parsed this string into date format.

Then put an if statement in the DefaultNewRowValue property of the CalendarCell class which decides whether to use Date.Now or lblMonth.Text in the cell.

The first two lines of the code are in a seperate event handler. lblMonth.Text is set to null on page load. When the user selects a month from my ComboBox then lblMonth.Text = Cstr(Date.Parse(testDate))

Maybe its not the ideal way to do it but it appears to be working correctly.

Thanks

        Dim testDate As String = "1/" & valMonth & "/" & Form1.lblYearTime.Text
        lblMonth.Text = CStr(Date.Parse(testDate))
	Public Overrides ReadOnly Property DefaultNewRowValue() As Object
            Get
                ' Use the current date and time as the default value.
                If Form2.lblMonth.Text = "" Then
                    Return Date.Now
                Else
                    Return MotorMileage.lblMonth.Text
                End If
            End Get
        End Property