Hướng dẫn và ví dụ Flutter IconButton

const IconButton (
    {Key key,
    double iconSize: 24.0,
    VisualDensity visualDensity,
    EdgeInsetsGeometry padding: const EdgeInsets.all(8.0),
    AlignmentGeometry alignment: Alignment.center,
    double splashRadius,
    @required Widget icon,
    Color color,
    Color focusColor,
    Color hoverColor,
    Color highlightColor,
    Color splashColor,
    Color disabledColor,
    @required VoidCallback onPressed,
    MouseCursor mouseCursor: SystemMouseCursors.click,
    FocusNode focusNode,
    bool autofocus: false,
    String tooltip,
    bool enableFeedback: true,
    BoxConstraints constraints}
)

@required Widget icon

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Title of Application',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  MyHomePage({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("IconButton Example"),
      ),
      body: Center(
          child:  IconButton (
              icon: Icon(Icons.directions_bus),
              onPressed: () {
                print("Pressed");
              }
          )
      ),
    );
  }
}

IconButton (
    icon: Image.network("https://raw.githubusercontent.com/o7planning/rs/master/flutter/feel_good_24.png"),
    onPressed: () {
      print("Pressed");
    }
)

IconButton (
    icon: Text("???????????"),
    onPressed: () {
      print("Pressed");
    }
)

double iconSize: 24.0

IconButton (
  icon: Image.network("https://raw.githubusercontent.com/o7planning/rs/master/flutter/feel_good_24.png"),
  onPressed: () {
    print("Pressed");
  },
  iconSize: 96
)

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Title of Application',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  MyHomePage({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold (

      appBar: AppBar(
        title: Text("IconButton Example"),
      ),
      body: Center(
          child: getIconButtons()
      ),
    );
  }

  Widget getIconButtons()  {
    double MAX_SIZE = 96;
    double LEFT = 30;
    return  Center(

        child: Column (

            children: [
              Row (
                  children: [
                    SizedBox(width: LEFT),
                    IconButton (
                      icon: Image.network("https://raw.githubusercontent.com/o7planning/rs/master/flutter/feel_good_96.png"),
                      onPressed: () {
                        print("Pressed");
                      },
                      iconSize: MAX_SIZE,
                    ),
                    Text("Real Size: 96"),
                    Text(" --- "),
                    Text("Set iconSize: " + MAX_SIZE.toString()),
                  ]
              ),
              Row (
                  children: [
                    SizedBox(width: LEFT),
                    IconButton (
                      icon: Image.network("https://raw.githubusercontent.com/o7planning/rs/master/flutter/feel_good_72.png"),
                      onPressed: () {
                        print("Pressed");
                      },
                      iconSize: MAX_SIZE,
                    ),
                    Text("Real Size: 72"),
                    Text(" --- "),
                    Text("Set iconSize: " + MAX_SIZE.toString()),
                  ]
              ),
              Row (
                  children: [
                    SizedBox(width: LEFT),
                    IconButton (
                      icon: Image.network("https://raw.githubusercontent.com/o7planning/rs/master/flutter/feel_good_24.png"),
                      onPressed: () {
                        print("Pressed");
                      },
                      iconSize: MAX_SIZE,
                    ),
                    Text("Real Size: 24"),
                    Text(" --- "),
                    Text("Set iconSize: " + MAX_SIZE.toString()),
                  ]
              ),
            ])
    );
  }
}

@required VoidCallback onPressed;

IconButton (
    icon: Icon(Icons.directions_bus),
    onPressed: () {
      print("Pressed");
    }
)

// Or:

Function onPressedHandler = () {
    print("Pressed");
};

....

IconButton (
    icon: Icon(Icons.directions_bus),
    onPressed: onPressedHandler
)

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Title of Application',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(),
    );
  }
}

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

  @override
  State<StatefulWidget> createState() {
    return MyHomePageState();
  }
}

class MyHomePageState extends State<MyHomePage> {
  int clickCount = 0;

  @override
  Widget build(BuildContext context) {
    return Scaffold (

        appBar: AppBar(
          title: Text("IconButton Example. Click count: " + this.clickCount.toString()),
        ),
        body: IconButton (
            icon: Icon(Icons.directions_bus),
            onPressed: ()  {
              setState(() {
                this.clickCount++;
              });
            }
        )
    );
  }
}

Color color

IconButton (
  icon: Icon(Icons.directions_boat),
  onPressed: () {
    print("Pressed");
  },
  iconSize: MAX_SIZE,
  color: Colors.blue,
),

Color disabledColor

IconButton (
  icon: Icon(Icons.directions_boat),
  iconSize: 64
  disabledColor: Colors.black45,
),

double splashRadius

IconButton (
  icon: Icon(Icons.directions_bus),
  onPressed: () {
    print("Pressed");
  },
  splashRadius: 50,
)

Color splashColor

IconButton (
    icon: Icon(Icons.directions_bus),
    onPressed: () {
      print("Pressed");
    },
    splashRadius: 100,
    splashColor: Colors.lightGreenAccent
)

Color highlightColor

IconButton (
  icon: Icon(Icons.directions_bus),
  onPressed: () {
    print("Pressed");
  },
  splashRadius: 100,
  splashColor: Colors.blue,
  highlightColor: Colors.red,
),

Color hoverColor

Color focusColor

String tooltip

IconButton (
  icon: Icon(Icons.directions_bus),
  onPressed: () {
    print("Pressed");
  },
  iconSize: 64,
  tooltip: "Bus Direction",
)

FocusNode focusNode

bool autofocus: false

bool enableFeedback: true

VisualDensity visualDensity;

EdgeInsetsGeometry padding: const EdgeInsets.all(8.0)

IconButton (
    icon: Icon(Icons.directions_bus),
    onPressed: () {},
    color: Colors.blue,
    padding: EdgeInsets.all(10)
)

IconButton (
    icon: Icon(Icons.directions_car),
    onPressed: () {},
    color: Colors.blue,
    padding: EdgeInsets.fromLTRB(50, 10, 30, 10)
)

AlignmentGeometry alignment: Alignment.center

BoxConstraints constraints

MouseCursor mouseCursor: SystemMouseCursors.click