我假设的事实：
- 您希望能够从列表中删除（或添加）一个字段
- 您希望在删除字段时保留剩余字段的值
- 列表可以大于 5
解决方案：
如果您希望以上所有内容都为真，那么您实际上需要跟踪 TextField 的 TextEditingControllers，而不是文本字段本身。这是因为 TextField 的值实际上存储在 TextEditingController 中（如果您不为每个小部件提供它，它会在运行中重新创建）。看看这个：
import 'package:flutter/material.dart';
// needs to be StatefulWidget, so we can keep track of the count of the fields internally
class PlayerList extends StatefulWidget {
const PlayerList({
this.initialCount = 5,
});
// also allow for a dynamic number of starting players
final int initialCount;
@override
_PlayerListState createState() => _PlayerListState();
}
class _PlayerListState extends State<PlayerList> {
int fieldCount = 0;
int nextIndex = 0;
// you must keep track of the TextEditingControllers if you want the values to persist correctly
List<TextEditingController> controllers = <TextEditingController>[];
// create the list of TextFields, based off the list of TextControllers
List<Widget> _buildList() {
int i;
// fill in keys if the list is not long enough (in case we added one)
if (controllers.length < fieldCount) {
for (i = controllers.length; i < fieldCount; i++) {
controllers.add(TextEditingController());
}
}
i = 0;
// cycle through the controllers, and recreate each, one per available controller
return controllers.map<Widget>((TextEditingController controller) {
int displayNumber = i + 1;
i++;
return TextField(
controller: controller,
maxLength: 20,
decoration: InputDecoration(
labelText: "Player $displayNumber",
counterText: "",
prefixIcon: const Icon(Icons.person),
suffixIcon: IconButton(
icon: Icon(Icons.clear),
onPressed: () {
// when removing a TextField, you must do two things:
// 1. decrement the number of controllers you should have (fieldCount)
// 2. actually remove this field's controller from the list of controllers
setState(() {
fieldCount--;
controllers.remove(controller);
});
},
),
),
);
}).toList(); // convert to a list
}
@override
Widget build(BuildContext context) {
// generate the list of TextFields
final List<Widget> children = _buildList();
// append an 'add player' button to the end of the list
children.add(
GestureDetector(
onTap: () {
// when adding a player, we only need to inc the fieldCount, because the _buildList()
// will handle the creation of the new TextEditingController
setState(() {
fieldCount++;
});
},
child: Container(
color: Colors.blue,
child: Padding(
padding: const EdgeInsets.all(16),
child: Text(
'add player',
style: TextStyle(
color: Colors.white,
),
),
),
),
),
);
// build the ListView
return ListView(
padding: EdgeInsets.all(0),
shrinkWrap: true,
physics: NeverScrollableScrollPhysics(),
children: children,
);
}
@override
void initState() {
super.initState();
// upon creation, copy the starting count to the current count
fieldCount = widget.initialCount;
}
@override
void dispose() {
super.dispose();
}
@override
void didUpdateWidget(PlayerList oldWidget) {
super.didUpdateWidget(oldWidget);
}
@override
void didChangeDependencies() {
super.didChangeDependencies();
}
}
通过以上内容，您可以：
- 启动应用程序
- 将播放器 2 更改为“鲍勃”
- 将玩家 3 更改为“史蒂夫”
- 将播放器 4 更改为“查尔斯”
- 删除播放器 3
- 观察玩家 2 是 'bob' 而新玩家 3 是 'charles'
我认为这就是您要在这里寻找的。p>