Responding to User Actions at Runtime

You can modify grid behavior by writing event handlers to respond to specific actions within the grid at runtime. Because a grid typically displays many fields and records at once, you may have very specific needs to respond to changes to individual columns. For example, you might want to activate and deactivate a button elsewhere on the form every time a user enters and exits a specific column.

The following table lists the grid events available in the Object Inspector.

Grid control events

Event	Purpose
OnCellClick	Occurs when a user clicks on a cell in the grid.
OnColEnter	Occurs when a user moves into a column on the grid.
OnColExit	Occurs when a user leaves a column on the grid.
OnColumnMoved	Occurs when the user moves a column to a new location.
OnDblClick	Occurs when a user double clicks in the grid.
OnDragDrop	Occurs when a user drags and drops in the grid.
OnDragOver	Occurs when a user drags over the grid.
OnDrawColumnCell	Occurs when application needs to draw individual cells.
OnDrawDataCell	(obsolete) Occurs when application needs to draw individual cells if State is csDefault.
OnEditButtonClick	Occurs when the user clicks on an ellipsis button in a column.
OnEndDrag	Occurs when a user stops dragging on the grid.
OnEnter	Occurs when the grid gets focus.
OnExit	Occurs when the grid loses focus.
OnKeyDown	Occurs when a user presses any key or key combination on the keyboard when in the grid.
OnKeyPress	Occurs when a user presses a single alphanumeric key on the keyboard when in the grid.
OnKeyUp	Occurs when a user releases a key when in the grid.
OnStartDrag	Occurs when a user starts dragging on the grid.
OnTitleClick	Occurs when a user clicks the title for a column.

There are many uses for these events. For example, you might write a handler for the OnDblClick event that pops up a list from which a user can choose a value to enter in a column. Such a handler would use the SelectedField property to determine to current row and column.