Occurs when a cell's shortcut menu is needed.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
When you handle the event, the shortcut menu that you specify in the handler is shown whenever the user right-clicks a cell. This is useful when you want to display a shortcut menu determined by the current state or value of a cell.
The event also occurs whenever the value of the DataGridViewCell.ContextMenuStrip property is retrieved, either programmatically or when the user right-clicks a cell.
You can use the DataGridViewCellEventArgs.ColumnIndex and RowIndex properties to determine the state or value of a cell, and use this information to change or modify the DataGridViewCellContextMenuStripNeededEventArgs.ContextMenuStrip property. This property is initialized with the value of the cell ContextMenuStrip property, which the event value overrides.
Handle the event when working with large amounts of data to avoid the performance penalties of setting the cell ContextMenuStrip value for multiple cells. For more information, see Best Practices for Scaling the Windows Forms DataGridView Control.
You can also specify shortcut menus for individual rows rather than individual cells by setting the row ContextMenuStrip property or handling the RowContextMenuStripNeeded event. The cell ContextMenuStrip property setting overrides the row ContextMenuStrip property setting, and the event overrides both the RowContextMenuStripNeeded event and the row ContextMenuStrip property setting. However, you can specify a null reference (Nothing in Visual Basic) for a cell shortcut menu to prevent a row shortcut menu from being overridden.
For more information about handling events, see Consuming Events.