How to set prefix vertical alignment in a TextFormField in Flutter?

Question

I'm trying to create a custom input in Flutter with a superscript text right before the input (which is borderless) like the image:

KuKu · Answer 1 · 2020-06-19T15:01:15.780

How about you wrap 'TextFormField' with column widget. I added full code with screenshot.

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> {
  void _incrementCounter() {
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          Row(
            children: <Widget>[
              Text('\$'),
              Expanded(
                child: TextFormField(),
              ),
            ],
          ),
        ],
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

I want only the "$" sign to be up, not the whole TextFormField() — Luis Abe, Jun 16 '20 at 13:27
I couldn't figure out a code with the '$', but look at the image thats I what I was trying to do. Maybe a better example is this image: [link](https://techpanorama.org/wp-content/uploads/2019/11/5dcafa2b3afd375eb842af8a.jpeg) the user can type the money he is willing to change and the '$' is always at the left-top side of the input — Luis Abe, Jun 19 '20 at 14:24

score 0 · Answer 2 · answered Dec 18 '20 at 15:40

Consider using an icon (attach_money) and controlling the size (size: 22.0,) to get the vertical positioning right, instead of a text dollar sign Text('\$'),

Here's the code:

Row(
                  children: <Widget>[
                    Icon(
                      Icons.attach_money,
                      size: 22.0,
                    ),
                    //Text('\$'),
                    Expanded(
                      child: TextFormField(),
                    ),
                  ],
                ),

And here's how it looks in my Android emulator:

How to set prefix vertical alignment in a TextFormField in Flutter?

2 Answers2