- A
Key is an identifier for Widgets, Elements and SemanticsNodes.
- A new widget will only be used to update an existing element if its key is the same as the key of the current widget associated with the element.
- Keys must be unique amongst the Elements with the same parent.
- Subclasses of
Key should either subclass LocalKey or GlobalKey.
- Keys are useful when manipulating collections of widgets of the same type.
- If you find yourself adding, removing, or reordering a collection of widgets of the same type that hold some state, then, you should use a key.
VietMX Staff asked 4 years ago
