flutter 父组件调用自组件方法

1、在自组件中
重要的是 这句代码 GlobalKey<_ChildState> globalKey = GlobalKey();

import 'package:flutter/material.dart';

GlobalKey<_ChildState> globalKey = GlobalKey();

class Child extends StatefulWidget {
     
  Child({
     
    Key key,
  }) : super(key: key);
  @override
  _ChildState createState() => _ChildState();
}
class _ChildState extends State<Child> {
     
	
	//子组件方法
	childMethod(){
     }
	....
}

2、父组件中

import 'package:flutter/material.dart';

class Parent extends StatefulWidget {
     
  Parent({
     }) : super(key: key);
  @override
  _ParentState createState() => _ParentState();
}
class _ParentState extends State<Parent> {
     
	parentMethod(){
     
		//父组件中调用
		globalKey.currentState.childMethod(_contractOrder)
	}
 	@override
  	Widget build(BuildContext context) {
     
    	return Child(key: globalKey)
    }
}