How to reduce the width of button and put it in center - flutter

Question

I have just started learning flutter, I have a screen that contains a form, I'd like to know how to reduce the width of button and put it in center.
This the code:
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Ajouter note'),
centerTitle: true,
backgroundColor: Colors.pink,
),
body: Container(
padding: EdgeInsets.all(10.0),
child: Form(
key: _formKey,
child: ListView(
children: <Widget>[
TextFormField(
decoration: InputDecoration(
hintText: 'Saisir un titre',
),
validator: (value) {
if (value.isEmpty) {
return 'Please enter some text';
}
return null;
},
),
SizedBox(
height: 10.0,
),
TextFormField(
minLines: 10,
maxLines: 10,
decoration: InputDecoration(
hintText: 'Saisir une déscription',
),
// The validator receives the text that the user has entered.
validator: (value) {
if (value.isEmpty) {
return 'Please enter some text';
}
return null;
},
),
SizedBox(
height: 10.0,
),
RaisedButton.icon(
onPressed: () {
if (_formKey.currentState.validate()) {
Scaffold.of(context).showSnackBar(
SnackBar(content: Text('Processing Data')));
}
},
label: Text(
'Enregistrer',
style: TextStyle(
fontSize: 16.0,
color: Colors.white,
),
),
icon: Icon(
Icons.save,
color: Colors.white,
),
color: Colors.pink,
),
],
),
),
),
);
}

Answer 1

One way could be wrapping the RaisedButton in a Padding.
You can apply padding only horizontal axis.
Padding(
padding: const EdgeInsets.symmetric(horizontal: 40),
child: // your RaisedButton
}

Answer 2

There are a lot of ways of doing it. One option is to limit the size of your button like this:
Center(
child: SizedBox(
width: 100,
child: RaisedButton(
...
),
),
)