一统天下 flutter https://github.com/webabcd/flutter_demo
作者 webabcd
一统天下 flutter - widget 状态管理: 状态管理 - 在树上，子获取父的数据
示例如下:
lib\state\find_ancestor.dart
/*
* 状态管理 - 在树上，子获取父的数据
*
* 在树上，子通过 context 的 findAncestorWidgetOfExactType(), findAncestorStateOfType() 查找父
*/
import 'package:flutter/material.dart';
import '../helper.dart';
class FindAncestorDemo extends StatefulWidget {
const FindAncestorDemo({Key? key}) : super(key: key);
final myName = "webabcd";
@override
_FindAncestorDemoState createState() => _FindAncestorDemoState();
}
class _FindAncestorDemoState extends State<FindAncestorDemo> {
final myAge = 44;
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.orange,
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
/// 在 State<T> 中调用相关的 StatefulWidget 中的属性或方法
MyText(widget.myName),
MyWidget(),
],
),
),
);
}
}
class MyWidget extends StatefulWidget {
const MyWidget({Key? key}) : super(key: key);
@override
_MyWidgetState createState() => _MyWidgetState();
}
class _MyWidgetState extends State<MyWidget> {
@override
Widget build(BuildContext context) {
/// findAncestorWidgetOfExactType() - 用于一层一层地向上查找需要的 Widget
var parentWidget = context.findAncestorWidgetOfExactType<FindAncestorDemo>()!;
/// findAncestorStateOfType() - 用于一层一层地向上查找需要的 State
var parentState = context.findAncestorStateOfType<_FindAncestorDemoState>()!;
/// 在树上，子获取父的数据
return MyText("${parentWidget.myName}, ${parentState.myAge}");
}
}
一统天下 flutter https://github.com/webabcd/flutter_demo
作者 webabcd