DataGridViewCellCancelEventHandler Delegate
.NET Framework (current version)
Represents the method that will handle the CellBeginEdit and RowValidating events of a DataGridView.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
Public Delegate Sub DataGridViewCellCancelEventHandler ( sender As Object, e As DataGridViewCellCancelEventArgs )
Parameters
- sender
-
Type:
System.Object
The source of the event.
- e
-
Type:
System.Windows.Forms.DataGridViewCellCancelEventArgs
A DataGridViewCellCancelEventArgs that contains the event data.
When you create a DataGridViewCellCancelEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see NIB: Events and Delegates.
The following code example uses a DataGridViewCellCancelEventHandler delegate to check if valid track and release dates are entered.
Private Sub ValidateByRow(ByVal sender As Object, _ ByVal data As DataGridViewCellCancelEventArgs) _ Handles songsDataGridView.RowValidating Dim row As DataGridViewRow = _ songsDataGridView.Rows(data.RowIndex) Dim trackCell As DataGridViewCell = _ row.Cells(songsDataGridView.Columns("Track").Index) Dim dateCell As DataGridViewCell = _ row.Cells(songsDataGridView.Columns("Release Date").Index) data.Cancel = Not (IsTrackGood(trackCell) _ AndAlso IsDateGood(dateCell)) End Sub Private Function IsTrackGood(ByRef cell As DataGridViewCell) As Boolean If cell.Value.ToString().Length = 0 Then cell.ErrorText = "Please enter a track" songsDataGridView.Rows(cell.RowIndex).ErrorText = _ "Please enter a track" Return False ElseIf cell.Value.ToString().Equals("0") Then cell.ErrorText = "Zero is not a valid track" songsDataGridView.Rows(cell.RowIndex).ErrorText = _ "Zero is not a valid track" Return False ElseIf Not Integer.TryParse( _ cell.Value.ToString(), New Integer()) Then cell.ErrorText = "A Track must be a number" songsDataGridView.Rows(cell.RowIndex).ErrorText = _ "A Track must be a number" Return False End If Return True End Function Private Function IsDateGood(ByRef cell As DataGridViewCell) As Boolean If cell.Value Is Nothing Then cell.ErrorText = "Missing date" songsDataGridView.Rows(cell.RowIndex).ErrorText = _ "Missing date" Return False Else Try DateTime.Parse(cell.Value.ToString()) Catch ex As FormatException cell.ErrorText = "Invalid format" songsDataGridView.Rows(cell.RowIndex).ErrorText = _ "Invalid format" Return False End Try End If Return True End Function
.NET Framework
Available since 2.0
Available since 2.0
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