DataGridView.RowErrorTextNeeded Event
Assembly: System.Windows.Forms (in system.windows.forms.dll)
'Declaration Public Event RowErrorTextNeeded As DataGridViewRowErrorTextNeededEventHandler 'Usage Dim instance As DataGridView Dim handler As DataGridViewRowErrorTextNeededEventHandler AddHandler instance.RowErrorTextNeeded, handler
/** @event */ public void add_RowErrorTextNeeded (DataGridViewRowErrorTextNeededEventHandler value) /** @event */ public void remove_RowErrorTextNeeded (DataGridViewRowErrorTextNeededEventHandler value)
JScript supports the use of events, but not the declaration of new ones.
The RowErrorTextNeeded event occurs only when the DataSource property of the DataGridView control is set or its VirtualMode property is true. Handling the RowErrorTextNeeded event is useful when you want to determine the error for a row depending on its state and the values it contains.
When you handle the RowErrorTextNeeded event and specify error text in the handler, an error glyph appears in the row header unless the ShowRowErrors property is set to false. When the user moves the mouse pointer over the error glyph, the error text appears in a ToolTip.
The RowErrorTextNeeded event also occurs whenever the value of the DataGridViewRow.ErrorText property is retrieved.
You can use the DataGridViewRowErrorTextNeededEventArgs.RowIndex property to determine the state of a row or the values it contains, and use this information to change or modify the DataGridViewRowErrorTextNeededEventArgs.ErrorText property. This property is initialized with the value of the row ErrorText property, which the event value overrides.
Handle the RowErrorTextNeeded event when working with large amounts of data to avoid the performance penalties of setting the row ErrorText value for multiple rows. For more information, see Best Practices for Scaling the Windows Forms DataGridView Control.
For more information about handling events, see Consuming Events.
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.
Reference
DataGridView ClassDataGridView Members
System.Windows.Forms Namespace
DataGridView.DataSource Property
DataGridView.VirtualMode Property
DataGridView.ShowRowErrors Property
DataGridViewRowErrorTextNeededEventHandler
DataGridViewRowErrorTextNeededEventArgs
DataGridViewRowErrorTextNeededEventArgs.ErrorText
DataGridViewRow.ErrorText
OnRowErrorTextNeeded