DataGridView.RowValidating Event
Occurs when a row is validating.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
This event is analogous to the Control.Validating event. Use this event to perform validation on all the values of a row. If the row does not pass validation, set the CancelEventArgs.Cancel property to true. Canceling this event prevents the RowValidated, Control.Validating, and Control.Validated events from occurring, and also prevents the user from leaving the invalid row and prevents the row from being saved to an external data source in data bound mode.
For more information about handling events, see Consuming Events.
The following code example uses RowValidating 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
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.