为什么setState不能重述小部件类

Question

我已经为纸牌游戏编写了代码，试图使用扑克牌库显示纸牌，并且在小部件类中创建了显示玩家手牌，它可以在静态阶段以良好的顺序显示纸牌。然而，当我尝试发牌并将额外的牌添加到列表中(即手牌(，并设置State时，它并没有相应地更新筛选。有人能帮忙吗？

class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
Games _game = Games();
int _counter = 0;
List<Kar> desk = [];
List<Kar> remainingDesk = [];
Kar _drawnCard;
double _avgCounter = 0;
ShapeBorder shape = RoundedRectangleBorder(
borderRadius: BorderRadius.circular(8),
side: BorderSide(color: Colors.black, width: 1));
List<Kar> _playerA = [
Kar(suit: 1, rank: 14),
Kar(suit: 1, rank: 11),
];
List<Kar> _dealer = [
Kar(suit: 2, rank: 12),
Kar(suit: 3, rank: 13),
];
List<Kar> _blackJack = [
Kar(suit: 1, rank: 14),
Kar(suit: 1, rank: 11),
Kar(suit: 3, rank: 13),
];
double _cardSize = 0;
bool _selected = false;
bool _second = false;
bool _playerTurn = false;
bool _dealerTurn = false;
bool _playerTurnEnd = false;
bool _dealerTurnEnd = false;
int _handScore = 0;
@override
void initState() {
Games _games = Games();
setState(() {
desk = createDesk();
remainingDesk = List.from(desk);
});
_incrementCounter();
super.initState();
}
void _incrementCounter() {
setState(() {
_counter++;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
width: 300,
height: 580,
child: Stack(
children: [
PlayerHand(player: false, hand: _playerA),
Text('Score: ' + _handScore.toString()),
],
),
),
),
floatingActionButton: FloatingActionButton(
onPressed: () {
Kar _drawnCard = drawCardfromDesk(remainingDesk);
setState(() {
_handScore += _drawnCard.rank;
_playerA.add(_drawnCard);
});
});
},
tooltip: 'Increment',
child: Icon(Icons
.add)), // This trailing comma makes auto-formatting nicer for build methods.
);
}
List<Kar> createDesk() {
List<Kar> desk = [];
for (int _rank = 2; _rank < 15; _rank++) {
for (int _suit = 1; _suit < 5; _suit++) {
desk.add(Kar(suit: _suit, rank: _rank));
}
;
}
;
return desk;
}
Kar drawCardfromDesk(List<Kar> desk) {
Kar _dealCard;
var rng = new Random();
_dealCard = desk[rng.nextInt(desk.length)];
desk.remove(_dealCard);
return _dealCard;
}
}

import 'dart:convert';
import 'dart:io';
import 'package:blackjack/main.dart';
import 'package:flutter/material.dart';
import 'package:playing_cards/playing_cards.dart';

class PlayerHand extends StatefulWidget {
List<Kar> hand;
bool player= false;
BuildContext context;

PlayerHand({
@required this.hand,
@required this.player
});
@override
_PlayerHandState createState() => _PlayerHandState();
}
class _PlayerHandState extends State<PlayerHand> {
int _handLength=0;
bool _player= false;
ShapeBorder shape = RoundedRectangleBorder(
borderRadius: BorderRadius.circular(8),
side: BorderSide(color: Colors.black, width: 1));


@override
void initState() {
//var authBloc = Provider.of<AuthBloc>(context);
// TODO: implement initState
setState(() {
_handLength = widget.hand.length;
_player = widget.player;
});

super.initState();
}
@override
Widget build(BuildContext context) {
//final authBloc = Provider.of<AuthBloc>(context);

return _handLength==0
?Container()
: _handLength ==1
? Container(
child: PlayingCardView(
card: PlayingCard(
suitsName[widget.hand[0].suit], cardValue[widget.hand[0].rank]),
showBack: false,
shape: shape,
),
)
: _handLength ==2
? Container(
child:Container(
height: 180,
width: 380,
// duration: Duration(seconds: 1),
child: FlatCardFan(children: [
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[0].suit],
cardValue[widget.hand[0].rank]),
showBack: _player?true:false,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[1].suit],
cardValue[widget.hand[1].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
]))
)
: _handLength ==3
? Container(
child:Container(
height: 180,
width: 380,
//duration: Duration(seconds: 1),
child: FlatCardFan(children: [
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[0].suit],
cardValue[widget.hand[0].rank]),
showBack: _player?true:false,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[1].suit],
cardValue[widget.hand[1].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[2].suit],
cardValue[widget.hand[2].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
]))
): _handLength ==4
? Container(
child:Container(
height: 180,
width: 300,
// duration: Duration(seconds: 1),
child: FlatCardFan(children: [
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[0].suit],
cardValue[widget.hand[0].rank]),
showBack: _player?true:false,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[1].suit],
cardValue[widget.hand[1].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[2].suit],
cardValue[widget.hand[2].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[3].suit],
cardValue[widget.hand[3].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
]))
): _handLength ==5
? Container(
child:AnimatedContainer(
height: 180,
width: 300,
duration: Duration(seconds: 1),
child: FlatCardFan(children: [
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[0].suit],
cardValue[widget.hand[0].rank]),
showBack: _player?true:false,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[1].suit],
cardValue[widget.hand[1].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[2].suit],
cardValue[widget.hand[2].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[3].suit],
cardValue[widget.hand[3].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[4].suit],
cardValue[widget.hand[4].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
]))
) : _handLength ==6
?Container(
child:AnimatedContainer(
height: 180,
width: 300,
duration: Duration(seconds: 1),
child: FlatCardFan(children: [
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[0].suit],
cardValue[widget.hand[0].rank]),
showBack: _player?true:false,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[1].suit],
cardValue[widget.hand[1].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[2].suit],
cardValue[widget.hand[2].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[3].suit],
cardValue[widget.hand[3].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[4].suit],
cardValue[widget.hand[4].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[5].suit],
cardValue[widget.hand[5].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
]))
)
: Container(
child:AnimatedContainer(
height: 180,
width: 300,
duration: Duration(seconds: 1),
child: FlatCardFan(children: [
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[0].suit],
cardValue[widget.hand[0].rank]),
showBack: _player?true:false,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[1].suit],
cardValue[widget.hand[1].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[2].suit],
cardValue[widget.hand[2].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[3].suit],
cardValue[widget.hand[3].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[4].suit],
cardValue[widget.hand[4].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[5].suit],
cardValue[widget.hand[5].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[6].suit],
cardValue[widget.hand[6].rank]),
//showBack: true,
elevation: 3.0,
shape: shape),
])));
}

}

Answer 1

动态构建小部件：

FlatCardFan( 
children: List.generate(widget.hand.length, (index) =>  
PlayingCardView(
card: PlayingCard(suitsName[widget.hand[index].suit],
cardValue[widget.hand[0].rank]),
showBack: _player?true:false,
elevation: 3.0,
shape: shape
),
),
), 

让我知道这是否适合你。