Three options:
-
Control.TextChanged[
^]. Note that it is fired whenever the text changes, i.e. if you type 'Hello' you get 5 events. Useful for dynamic filtering of an autocomplete list or similar.
-
Control.Leave[
^], as mentioned by Nit. (LostFocus also works for this.) Called only when the user leaves the field.
- Use a KeyPress and look for Enter.
A combination of the last two is useful for 'actions': the action is submitted when the user leaves the field or presses Enter. The first is useful for things that should update every character, notably autocomplete lists but possibly also related tasks like preloading of 'guessed' resources or updating other fields.