我希望平面按钮文本更新为用户在警报消息文本字段中输入的文本

Question

我在我的项目中添加了一个平面按钮，它会弹出带有文本字段的警告消息。我希望那个平面按钮文本更新为用户在警告消息中输入的文本。

这是我创建警报对话框的函数。

Future<String> createAlertDialog(BuildContext context) {

    TextEditingController customController = TextEditingController();

    return showDialog(context: context, builder: (context){
      return AlertDialog(
        title:  Text("Your Name"),
        content: TextField(
          controller: customController,
        ),
        actions: <Widget>[
          MaterialButton(
            elevation: 5.0,
            child: Text("Submit"),
            onPressed: () {
              Navigator.of(context).pop(customController.text.toString());
            },
          )
        ],
      );
    });
  }

这是我想要接收它并更新当前显示 "Enter Your Name".

  List<Widget> codeField() {
    return [
      Container(
        child: Center(
          child: new FlatButton(
            child: new Text('Enter Your Name',
                style: new TextStyle(fontSize: 10.0)),
            onPressed: () {
              createAlertDialog(context).then((onValue) {
                SnackBar mySnackbar = SnackBar(content: Text("$onValue"));
                Scaffold.of(context).showSnackBar(mySnackbar);
              });
            }
          ),
        ),
      )
    ];
  }

Answer 1

您可以复制粘贴运行下面的完整代码
您可以将 FlatButton 换成 StatefulBuilder

代码片段

  String name = 'Enter Your Name';

  List<Widget> codeField() {
    return [
      Container(
        child: Center(child: new StatefulBuilder(
            builder: (BuildContext context, StateSetter setState) {
          return FlatButton(
              child: new Text('$name', style: new TextStyle(fontSize: 10.0)),
              onPressed: () {
                createAlertDialog(context).then((onValue) {
                  name = onValue;
                  print(onValue);
                  SnackBar mySnackbar = SnackBar(content: Text("$onValue"));
                  _scaffoldKey.currentState.showSnackBar(mySnackbar);
                  setState(() {});
                });
              });
        })),
      )
    ];
  }

工作演示

完整代码

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;
  final _scaffoldKey = GlobalKey<ScaffoldState>();

  Future<String> createAlertDialog(BuildContext context) {
    TextEditingController customController = TextEditingController();

    return showDialog(
        context: context,
        builder: (context) {
          return AlertDialog(
            title: Text("Your Name"),
            content: TextField(
              controller: customController,
            ),
            actions: <Widget>[
              MaterialButton(
                elevation: 5.0,
                child: Text("Submit"),
                onPressed: () {
                  Navigator.of(context).pop(customController.text.toString());
                },
              )
            ],
          );
        });
  }

  String name = 'Enter Your Name';

  List<Widget> codeField() {
    return [
      Container(
        child: Center(child: new StatefulBuilder(
            builder: (BuildContext context, StateSetter setState) {
          return FlatButton(
              child: new Text('$name', style: new TextStyle(fontSize: 10.0)),
              onPressed: () {
                createAlertDialog(context).then((onValue) {
                  name = onValue;
                  print(onValue);
                  SnackBar mySnackbar = SnackBar(content: Text("$onValue"));
                  _scaffoldKey.currentState.showSnackBar(mySnackbar);
                  setState(() {});
                });
              });
        })),
      )
    ];
  }

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      key: _scaffoldKey,
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
            mainAxisAlignment: MainAxisAlignment.center, children: codeField()),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

我希望平面按钮文本更新为用户在警报消息文本字段中输入的文本

I want Flat button text to update with the text entered by user on alert message Text field

alert

android

popup

dart

flutter