323

The main app screen doesn't have this issue, all the texts show up as they should.

However, in the new screen, all the text widget have some weird yellow line / double-line underneath.

Any ideas on why this is happening?

Yellow Lines

CopsOnRoad
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dasfima
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  • Can you add your code ? – Shady Aziza Nov 04 '17 at 21:58
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    I suspect the reason is because you do not have a Scaffold on this page. – Shady Aziza Nov 04 '17 at 22:33
  • @aziza I think you're right. This page doesn't have a scaffold. I suspected that might be the issue, but didn't follow through with checking it. Any ideas as to why this happens when I have no scaffold? I did not realise it was required. Should I just use a Scaffold anyway, even though I'm only gonna use the_body_ parameter? – dasfima Nov 05 '17 at 09:46
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    Each page needs a Scaffold, even if you are refactoring smaller widgets onto separate classes they should end up with a Scaffold parent somewhere. I am not sure if it is meant this way for the text to be underlined or it is an issue, regardless, you will end up needing to build any page within a Scaffold. – Shady Aziza Nov 05 '17 at 11:50
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    Or if you donot want `Scaffold`, you can just surround your `Text` with `Material` widget – realpac Mar 19 '18 at 18:46
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    Is this documented somewhere? Since I'm new to Flutter I couldn't figure out why my texts get double underline *by default* – Andrey Gordeev Apr 23 '19 at 15:10

16 Answers16

379

The problem is having a Scaffold or not. Scaffold is a helper for Material apps (AppBar, Drawer, that sort of stuff). But you're not forced to use Material.

What you're missing is an instance of DefaultTextStyle as a parent:

DefaultTextStyle(
  style: TextStyle(...),
  child: Text('Hello world'),
)

Various widgets add one to change the default text theme, such as Scaffold, Dialog, AppBar, ListTile, ...

It's DefaultTextStyle that allows your app-bar title to be bold by default for example.

Rémi Rousselet
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    Also keep in mind for a Hero, it is disconnected from the parent while 'in flight' so adding a `Material` (or any Theme) as the Hero's child (BOTH sides) fixes it in the transition. See https://github.com/flutter/flutter/issues/30647 – aaronvargas Jul 09 '19 at 16:36
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    @Rémi If you said Theme instance is missing in the parent, Why having Theme on top instead of Material or Scaffold doesn't help solve the problem? I just try it. – kitta Dec 31 '20 at 08:52
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    Just an update, It's the DefaultTextStyle, not Theme that's missing. – kitta Jan 01 '21 at 04:01
  • I just added another way to fix this in the answer below. – kitta Jan 01 '21 at 12:13
  • Adding a Theme parent does not solve the problem. `DefaultTextStyle` is the missing parent, as per [documentation](https://github.com/flutter/flutter/blob/52e2ca38fcacedf59ef519f15d05d20623473dab/packages/flutter/lib/src/material/app.dart#L22) – Andrei Tudor Diaconu Jul 21 '21 at 11:17
  • Scaffold adding as parent fixes the issue, Thanks!! – Happy Singh Feb 02 '22 at 18:34
  • This is not an accurate answer. I have a Theme parent and the issue still exists. – Scorb Mar 02 '22 at 23:20
  • Wrapping main widget within 'Scaffold' worked for me. – Om Prakash May 29 '23 at 10:22
185

Add Material widget as root element.

@override
  Widget build(BuildContext context) {
    return Material(
        type: MaterialType.transparency,
        child: new Container(
Andrey Gordeev
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Dyvoker
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114

All you need to do is provide a Material widget, or a Scaffold which internally covers this widget. You can do that in the following ways:

  • Use Material (simple and better):

    Material(
      color: Colors.transparent, // <-- Add this, if needed
      child: Text('Hello'),
    )
    
  • Set Text.style property:

    Text(
      'Hello',
      style: TextStyle(decoration: TextDecoration.none), // Set this
    )
    
  • Provide Scaffold:

    Scaffold(body: Text('Hello'))
    

Fixing yellow text issues when using Hero :

As aaronvargas mentioned, you can wrap your child in Material when using Hero on both sides. For example:

Hero(
  tag: 'fooTag',
  child: Material( // <--- Provide Material
    type: MaterialType.transparency,
    child: YourWidget(),
  ),
);
CopsOnRoad
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46

Text style has a decoration argument that can be set to none

Text("My Text",
  style: TextStyle(
    decoration: TextDecoration.none,
  )
);

Also, as others have mentioned, if your Text widget is in the tree of a Scaffold or Material widget you won't need the decoration text style.

Aaron Halvorsen
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18

Just adding another way I encounter to these answers.

Wrap the root Widget around a DefaultTextStyle widget. Altering each Text widget is not a necessity here.

DefaultTextStyle(
    style: TextStyle(decoration: TextDecoration.none), 
    child : Your_RootWidget
)

Hope it helps someone.

Nikhileshwar
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17

Also you can use decoration: TextDecoration.none to remove underline

Anirudh Sharma
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7

You should add Material and Scaffold widgets in main.dart file

 MaterialApp(
  home: Scaffold(
    body: Text('Hello world'),
  ),
);
kokemomuke
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4

Before

enter image description here

  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        Center(
          child: Text(
            "21:34",
            style: TextStyle(fontSize: 50),
          ),
        ),
        Center(
          child: Text(
            "Wakey - wakey",
            style: TextStyle(fontSize: 20),
          ),
        )
      ],
    );
  }

After (Solution):

Here Wrap the current top or parent widget with Scaffold widget

enter image description here

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Center(
            child: Text(
              "21:34",
              style: TextStyle(fontSize: 50),
            ),
          ),
          Center(
            child: Text(
              "Wakey - wakey",
              style: TextStyle(fontSize: 20),
            ),
          )
        ],
      ),
    );
  }

Full code:Dartpad or Live code

import 'package:flutter/material.dart';

void main() => runApp(MaterialApp(home: sta()));

class sta extends StatefulWidget {
  const sta({Key? key}) : super(key: key);

  @override
  State<sta> createState() => _staState();
}

var isShow = false;


class _staState extends State<sta> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Center(
            child: Text(
              "21:34",
              style: TextStyle(fontSize: 50),
            ),
          ),
          Center(
            child: Text(
              "Wakey - wakey",
              style: TextStyle(fontSize: 20),
            ),
          )
        ],
      ),
    );
  }
}
lava
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3

You just need to add Material root widget.

      @override
       Widget build(BuildContext context) {
      return Material(
         child: new Container(),
        );
       }
Paras Sharma
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3

problem: your widget doesn't have default text style,

solution: wrap it in one!

DefaultTextStyle(
    style: TextStyle(),
    child: yourWidget,
  );

remember if you dont set any color, default text color is white!

Ali80
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2

There is an other solution for this , especially if you are using multiple pages wrapped under main.dart file You can do something like this:

  child: MaterialApp(
    home: Material(child: Wrapper()),
  ),

This will remove the yellow lines under text that is present in any pages referenced/used under wrapper.

Abdulmanan
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2

The yellow lines come from _errorTextStyle. The documentation states that you should define a DefaultTextStyle parent (or use Material, which does this for you):

MaterialApp uses this TextStyle as its DefaultTextStyle to encourage developers to be intentional about their DefaultTextStyle.

In Material Design, most Text widgets are contained in Material widgets, which sets a specific DefaultTextStyle. If you're seeing text that uses this text style, consider putting your text in a Material widget (or another widget that sets a DefaultTextStyle).

Developing Flutter apps without material is not something most people do, but if that's your use case, you should use DefaultTextStyle.

Contrary to the accepted answer, Theme does not set a DefaultTextStyle, so it does not solve your problem. Scaffold does solve the problem, as it contains Material, which in turn defines DefaultTextStyle, but Scaffold is a bit more than you need for a Dialog, Hero, etc.

To permanently solve this for your whole app, you could set the DefaultTextStyle in your MaterialApp builder. This solves the issue for all the components of your app, not just the current screen you're working on.

Andrei Tudor Diaconu
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1

I recommend this approach because you could do it once and it will override your whole app.

Add DefaultTextStyle under builder of our MaterialApp like so:

child: MaterialApp(      
  ...
  ...
  theme: yourThemeData,
  builder: (context, child) => DefaultTextStyle(
    style: yourThemeData.textTheme.bodyText1,
    child: child,
  ),
),

By doing so we don't need to specify a style or having DefaultTextTheme every time we want to use showDialog or Overlay.

kitta
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1

You can also have your scaffold as the home for your MaterialApp. This worked for me.

return MaterialApp(
  home: Scaffold(
    body: Container(
      child: SingleChildScrollView(child: Text('Test')),
    ),
  ),
);
0

The text has a hidden default text style .The problem arises because you can't provide this to any parent widget like Scaffold. Text widget takes the default style. for your solution either you can change the DefaultTextStyle like this.

DefaultTextStyle(
    style: TextStyle(),
    child: yourTextWidget,
  );

or just wrap into Scaffold, Scaffold is a widget. that provides scaffolding for pages in your app. like this

 MaterialApp(
  home: Scaffold(
    body: Text('Wakey Wakey!'),
  ),
);

for more info just walk through this Flutter Official video.

Yellow underline text | Decoding Flutter

Shirsh Shukla
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0

Use a DefaultTextStyle() widget to set the textstyle of your text.

DefaultTextStyle(
  style: kTempTextStyle,
  child: Text('Hello world'),
)

you can give your own textstyle as you want.

const kTempTextStyle = TextStyle(
  fontFamily: 'Spartan MB',
  fontSize: 100.0,
  decoration: null,
);
keikai
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iamSahil
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