DataGridView.CellValidating Event

 

Occurs when a cell loses input focus, enabling content validation.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

Public Event CellValidating As DataGridViewCellValidatingEventHandler

Canceling this event cancels the changes to the current cell. When this event is canceled in data-bound mode, the new value is not pushed to the underlying data source. When this event is canceled in virtual mode, the CellValuePushed event will not be raised.

Handle the CellValidated event to perform post-validation processing.

For more information about handling events, see NIB: Consuming Events.

The following code example handles the CellValidating event to ensure that only positive integers are entered by the user. This example is part of a larger example available in the VirtualMode reference topic.

Private Sub dataGridView1_CellValidating(ByVal sender As Object, _
    ByVal e _
    As DataGridViewCellValidatingEventArgs) _
    Handles dataGridView1.CellValidating

    Me.dataGridView1.Rows(e.RowIndex).ErrorText = ""
    Dim newInteger As Integer

    ' Don't try to validate the 'new row' until finished 
    ' editing since there
    ' is not any point in validating its initial value.
    If dataGridView1.Rows(e.RowIndex).IsNewRow Then Return
    If Not Integer.TryParse(e.FormattedValue.ToString(), newInteger) _
        OrElse newInteger < 0 Then

        e.Cancel = True
        Me.dataGridView1.Rows(e.RowIndex).ErrorText = "the value must be a non-negative integer"

    End If
End Sub

.NET Framework
Available since 2.0
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