Flutter基础-IconButton

0

Sample

double _volume = 0.0;

// ...

Widget build(BuildContext context) {
  return Scaffold(
    body: Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          IconButton(
            icon: Icon(Icons.volume_up),
            tooltip: 'Increase volume by 10',
            onPressed: () {
              setState(() {
                _volume += 10;
              });
            },
          ),
          Text('Volume : $_volume')
        ],
      ),
    ),
  );
}

Sample in an App

// Flutter code sample for material.IconButton.1

// This sample shows an `IconButton` that uses the Material icon "volume_up" to
// increase the volume.

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

/// This Widget is the main application widget.
class MyApp extends StatelessWidget {
  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: Text(_title)),
        body: MyStatefulWidget(),
      ),
    );
  }
}

double _volume = 0.0;

class MyStatefulWidget extends StatefulWidget {
  MyStatefulWidget({Key key}) : super(key: key);

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

class _MyStatefulWidgetState extends State {
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            IconButton(
              icon: Icon(Icons.volume_up),
              tooltip: 'Increase volume by 10',
              onPressed: () {
                setState(() {
                  _volume += 10;
                });
              },
            ),
            Text('Volume : $_volume')
          ],
        ),
      ),
    );
  }
}

Adding a filled background

Sample

Widget build(BuildContext context) {
  return Center(
    child: Container(
      child: Ink(
        decoration: ShapeDecoration(
          color: Colors.lightBlue,
          shape: CircleBorder(),
        ),
        child: IconButton(
          icon: Icon(Icons.android),
          color: Colors.white,
          onPressed: () {
            print("filled background");
          },
        ),
      ),
    ),
  );
}

Sample in an App

// Flutter code sample for material.IconButton.2

// In this sample the icon button's background color is defined with an [Ink]
// widget whose child is an [IconButton]. The icon button's filled background
// is a light shade of blue, it's a filled circle, and it's as big as the
// button is.

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

/// This Widget is the main application widget.
class MyApp extends StatelessWidget {
  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: Text(_title)),
        body: MyStatelessWidget(),
      ),
    );
  }
}

/// This is the stateless widget that the main application instantiates.
class MyStatelessWidget extends StatelessWidget {
  MyStatelessWidget({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Container(
        child: Ink(
          decoration: ShapeDecoration(
            color: Colors.lightBlue,
            shape: CircleBorder(),
          ),
          child: IconButton(
            icon: Icon(Icons.android),
            color: Colors.white,
            onPressed: () {
              print("filled background");
            },
          ),
        ),
      ),
    );
  }
}