How to set margin for a Button in Flutter

Question

I am just creating a form in Flutter. I am not able to set the top margin for the button.

class _MyHomePageState extends State<MyHomePage> {

String firstname; 
String lastname;
final scaffoldKey = new GlobalKey<ScaffoldState>();
final formKey = new GlobalKey<FormState>();


    @override
  Widget build(BuildContext context) {
    return new Scaffold(
      key: scaffoldKey,
      appBar: new AppBar(
        title: new Text('Validating forms'),
      ),
      body: new Padding(
        padding: const EdgeInsets.all(16.0),
        child: new Form(
          key: formKey,
          child: new Column(
            children: [
              new TextFormField(
                decoration: new InputDecoration(labelText: 'First Name'),
                validator: (val) =>
                    val.length == 0 ?"Enter FirstName" : null,
                onSaved: (val) => firstname = val,
              ),
              new TextFormField(
                decoration: new InputDecoration(labelText: 'Password'),
                validator: (val) =>
                    val.length ==0 ? 'Enter LastName' : null,
                onSaved: (val) => lastname = val,
                obscureText: true,
              ),
              new RaisedButton(
                onPressed: _submit,
                child: new Text('Login'),
              ),
            ],
          ),
        ),
      ),
    );
  }

Solution 1

Put your button inside a Container and then set the margin

new Container(
    margin: const EdgeInsets.only(top: 10.0),
    child : new RaisedButton(
                onPressed: _submit,
                child: new Text('Login'),
              ),

Solution 2

Alternatively you can wrap your button with Padding. (That is what Container does internally.)

Padding(
  padding: const EdgeInsets.all(20),
  child: ElevatedButton(
    onPressed: _submit,
    child: Text('Login'),
  ),
);

See this answer more more on adding margin to a widget.

Note: RaisedButton is deprecated as of Flutter 2.0. ElevatedButton is the replacement.

Solution 3

In Flutter 2.0, RaisedButton was deprecated, The ElevatedButton is replacement.
So you can use ElevatedButton and set style as bellow to remove margin:

      ElevatedButton.icon(
        onPressed: () {},
        icon: Icon(Icons.add),
        label: Text(
          'Add Place',
        ),
        style: ButtonStyle(tapTargetSize: MaterialTapTargetSize.shrinkWrap),
      ),

Solution 4

image marging top:

        Scaffold(
      backgroundColor: Color.fromARGB(255, 238, 237, 237),
      body: Center(
        child: Container(
          margin: const EdgeInsets.only(top: 25),
          child: Column(
            children: <Widget>[
              Column(children: <Widget>[
                Image.asset(
                  'images/logo.png',
                  fit: BoxFit.contain,
                  width: 130,
                )
              ]),
              
            ],
          ),
        ),
      ),
    )

Solution 5

I found the EdgeInsets.symmetric:

child : new RaisedButton(
   onPressed: _submit,
   child: new Text('Login'),
   padding: EdgeInsets.symmetric(horizontal: 50, vertical: 10),
),

View more solutions

Comments

[Adam Smaka]

This should be accepted answer, because Padding can be marked as const, whereas Container cannot.

[Diana]

@AdamSmaka Out of curiosity - what is the advantage of sth being marked as const?

[Adam Smaka]

@Diana the value is build only once so the performance of an app is better