firka/flutter
3
0
Fork 1
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Add UniqueKey documentation regarding const constructor (#46647)

Browse Source
This commit is contained in:
Shi-Hao Hong
2019-12-10 13:24:58 -05:00
committed by GitHub
parent ac9fefdfa6
commit 0bec3dc3d2
1 changed files with 7 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
packages/flutter/lib/src/widgets/framework.dart
View File

@@ -39,8 +39,15 @@ export 'package:flutter/rendering.dart' show RenderObject, RenderBox, debugDumpR
// KEYS
/// A key that is only equal to itself.
///
/// This cannot be created with a const constructor because that implies that
/// all instantiated keys would be the same instance and therefore not be unique.
class UniqueKey extends LocalKey {
/// Creates a key that is equal only to itself.
///
/// The key cannot be created with a const constructor because that implies
/// that all instantiated keys would be the same instance and therefore not
/// be unique.
// ignore: prefer_const_constructors_in_immutables , never use const for this class
UniqueKey();