datagridview listindex for a combobox column

Question

Hi All:

I am using vb.Net 2008.  I have an unbound datagridview and column 2 is a combobox column.  Is there a way for me to get the selectedindex of the combobox?  I would appreciate a code.  Thanks;

Bob

Answer 1

try this:

http://code.msdn.microsoft.com/extended-dgv-106a60a0

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thanks for any help

Answer 2

Thank you Paul.  I will look at this in a couple of days as I have to work on other stuff for the next few days.

Bob

Answer 3

Hi,

To get the selected index from selected item of dataGridViewComboBoxCell, you will have to do some "work around" to get it. There is no direct way of getting it.

This is my example code to show you how its done:

Public Sub New()
	InitializeComponent()

	dataGridView1.Columns.Add("col1", "column 1") 'some othe columns        
	Dim comboCol As DataGridViewComboBoxColumn = CreateComboBox()
	dataGridView1.Columns.Add(comboCol)
        'adding some example rows to dgv (you can remove this bellow):
	For i As Integer = 0 To 5
		dataGridView1.Rows.Add(i.ToString())
	Next
End Sub

Private Function CreateComboBox() As DataGridViewComboBoxColumn
	Dim cmbcolumn As New DataGridViewComboBoxColumn()
	If True Then
		cmbcolumn.Name = "col2"
		cmbcolumn.HeaderText = "column 2"
		cmbcolumn.Items.AddRange(New String() {"aa", "ac", "aacc"}) 'exampe data of comboBox
		dataGridView1.EditingControlShowing += New DataGridViewEditingControlShowingEventHandler(AddressOf dataGridView1_EditingControlShowing)
	End If
	Return cmbcolumn
End Function

Private Sub dataGridView1_EditingControlShowing(sender As Object, e As DataGridViewEditingControlShowingEventArgs)
	Dim combo As ComboBox = TryCast(e.Control, ComboBox)
	If combo IsNot Nothing Then
		' Remove an existing event-handler, if present, to avoid 
		' adding multiple handlers when the editing control is reused.
		combo.SelectedIndexChanged -= New EventHandler(AddressOf ComboBox_SelectedIndexChanged)

		' Add the event handler. 
		combo.SelectedIndexChanged += New EventHandler(AddressOf ComboBox_SelectedIndexChanged)
	End If
End Sub

Private Sub ComboBox_SelectedIndexChanged(sender As Object, e As EventArgs)
	Dim cb As ComboBox = DirectCast(sender, ComboBox)
	Dim index As Integer = cb.SelectedIndex
	MessageBox.Show("Selected index is " & index)
End Sub

Hope it helps, 

bye, bye

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Mitja

Answer 4

Hi Mitja:

I pasted your code in my form, and it would not run.  there were compile errors.

Bob

Answer 5

Hi Mark:

I looked at your control.  How would I get the selectedindex of the combobox item?  in the cellSelectedIndexChanged event, I did not see a property under e. for the selectedindex.  Thanks.

Bob

Answer 6

Hi Mark:

I looked at your control.  How would I get the selectedindex of the combobox item?  in the cellSelectedIndexChanged event, I did not see a property under e. for the selectedindex.  Thanks.

Bob

you mean my control, right?

here it is with a selectedIndex property:

Public Class DataGridViewEx
    Inherits DataGridView

    Public Event cellSelectedIndexChanged(ByVal sender As System.Object, ByVal e As ComboIndexChangedEventArgs)
    Public Event cellCheckedChanged(ByVal sender As System.Object, ByVal e As CheckBoxChangedEventArgs)

    Public Sub New()
    End Sub

    Protected Overrides Sub OnEditingControlShowing(ByVal e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs)
        ' Attempt to cast the EditingControl to a ComboBox.
        'this will only work if CurrentCell is a combobox column
        Dim cb As ComboBox = TryCast(e.Control, ComboBox)
        'if it is a combobox column...
        If cb IsNot Nothing Then
            RemoveHandler cb.SelectedIndexChanged, AddressOf DGVComboIndexChanged
            AddHandler cb.SelectedIndexChanged, AddressOf DGVComboIndexChanged
        End If
        MyBase.OnEditingControlShowing(e)
    End Sub

    Private Sub DGVComboIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
        'this handles the datagridviewcombobox cell selectedindexchanged event
        Dim cb As ComboBox = DirectCast(sender, ComboBox)
        RaiseEvent cellSelectedIndexChanged(sender, New ComboIndexChangedEventArgs With {.columnIndex = MyBase.CurrentCell.ColumnIndex, .rowIndex = MyBase.CurrentCell.RowIndex, .selectedIndex = cb.SelectedIndex, .selectedItem = cb.SelectedItem, .selectedValue = cb.SelectedValue, .text = cb.Text})
    End Sub

    Protected Overrides Sub OnCurrentCellDirtyStateChanged(ByVal e As System.EventArgs)
        If TypeOf MyBase.CurrentCell Is DataGridViewCheckBoxCell Then
            MyBase.CommitEdit(DataGridViewDataErrorContexts.Commit)
        End If
        MyBase.OnCurrentCellDirtyStateChanged(e)
    End Sub

    Protected Overrides Sub OnCellValueChanged(ByVal e As System.Windows.Forms.DataGridViewCellEventArgs)
        If e.ColumnIndex = -1 OrElse e.RowIndex = -1 Then Return
        If TypeOf MyBase.Rows(e.RowIndex).Cells(e.ColumnIndex) Is DataGridViewCheckBoxCell Then
            RaiseEvent cellCheckedChanged(Me, New CheckBoxChangedEventArgs With {.columnIndex = e.ColumnIndex, .rowIndex = e.RowIndex, .newValue = If(MyBase.Rows(e.RowIndex).Cells(e.ColumnIndex).Value Is Nothing, False, CBool(MyBase.Rows(e.RowIndex).Cells(e.ColumnIndex).Value))})
        End If
        MyBase.OnCellValueChanged(e)
    End Sub

End Class

Public Class ComboIndexChangedEventArgs
    Public columnIndex As Integer
    Public rowIndex As Integer
    Public selectedIndex as integer
    Public selectedItem As Object
    Public selectedValue As Object
    Public text As String
End Class

Public Class CheckBoxChangedEventArgs
    Public columnIndex As Integer
    Public rowIndex As Integer
    Public newValue As Boolean
End Class

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thanks for any help

Answer 7

Thank you Paul.  It works great.