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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)

'Declaration
Public Event CellValidating As DataGridViewCellValidatingEventHandler
'Usage
Dim instance As DataGridView 
Dim handler As DataGridViewCellValidatingEventHandler 

AddHandler instance.CellValidating, handler

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 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

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.

.NET Framework

Supported in: 3.5, 3.0, 2.0
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