DataGridView Events


.NET Framework Class Library
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)
Syntax

Visual Basic (Declaration)
Public Event CellValidating As DataGridViewCellValidatingEventHandler
Visual Basic (Usage)
Dim instance As DataGridView
Dim handler As DataGridViewCellValidatingEventHandler

AddHandler instance.CellValidating, handler
C#
public event DataGridViewCellValidatingEventHandler CellValidating
Visual C++
public:
 event DataGridViewCellValidatingEventHandler^ CellValidating {
    void add (DataGridViewCellValidatingEventHandler^ value);
    void remove (DataGridViewCellValidatingEventHandler^ value);
}
JScript
JScript does not support events.
Remarks

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.

Examples

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.

Visual Basic
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
C#
private void dataGridView1_CellValidating(object sender,
    DataGridViewCellValidatingEventArgs e)
{
    dataGridView1.Rows[e.RowIndex].ErrorText = "";
    int newInteger;

    // 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) { return; }
    if (!int.TryParse(e.FormattedValue.ToString(),
        out newInteger) || newInteger < 0)
    {
        e.Cancel = true;
        dataGridView1.Rows[e.RowIndex].ErrorText = "the value must be a non-negative integer";
    }
}
Visual C++
void VirtualConnector::dataGridView1_CellValidating
    (Object^ sender, DataGridViewCellValidatingEventArgs^ e)
{
    int newInteger;

    // 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) 
    {
        return; 
    }
    if (!Int32::TryParse(e->FormattedValue->ToString(), 
        newInteger) || (newInteger < 0))
    {
        e->Cancel = true;
    }
}
Platforms

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.
Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0
See Also

Reference

Other Resources

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