將閃爍添加到按鈕

Question

我希望在用戶選擇單選按鈕時提醒用戶注意提交按鈕，並且我想知道是否無論如何要實現這個功能。我查看了RaisedButton文檔，但似乎沒有任何屬性閃爍或搖動按鈕。例如，下面的代碼最初沒有單選按鈕，所以按鈕變灰，一旦在多個單選按鈕中進行選擇，submit RaisedButton onPressed屬性值不再爲空，而是替換爲所需的操作;不過，我也想在那裏，如果選擇不同的單選按鈕的情況下，有一些方法來添加一些運動（閃光/震動按鈕）提交按鈕，但不會改變onPressed財產

new Radio<int>(
value: 1, 
groupValue: 0, 
onChanged: handleRadioValue 
) 

new RaisedButton(
child: const Text('SUBMIT') 
onPressed: selected 
) 

handleRadioValue(){ 
selected = groupValue == 0 ? null : submitButton(); 
//change Raised button to attract attention} 

Answer 1

可以吸引眼球動畫RaisedButton的color。當單選按鈕選擇發生變化時，此示例將提醒您注意RaisedButton，方法是將其顏色更改爲當前主題的disabledColor並返回。

import 'dart:math'; 
import 'package:flutter/material.dart'; 

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

class MyApp extends StatelessWidget { 
    @override 
    Widget build(BuildContext context) { 
    return new MaterialApp(
     title: 'Flutter Demo', 
     home: new MyHomePage(), 
    ); 
    } 
} 

class MyHomePage extends StatefulWidget { 
    MyHomePage({Key key}) : super(key: key); 
    @override 
    createState() => new MyHomePageState(); 
} 

class MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin { 
    AnimationController _controller; 
    int _radioValue; 

    @override initState() { 
    _controller = new AnimationController(
     vsync: this, 
     duration: const Duration(milliseconds: 100), 
    )..addStatusListener((AnimationStatus status) { 
     if (status == AnimationStatus.completed) 
     _controller.reverse(); 
    }); 
    super.initState(); 
    } 

    void _handleRadioValue(int value) { 
    // Don't animate the first time that the radio value is set 
    if (_radioValue != null) 
     _controller.forward(); 
    setState(() { 
     _radioValue = value; 
    }); 
    } 

    @override 
    Widget build(BuildContext context) { 
    ThemeData theme = Theme.of(context); 
    return new Scaffold(
     body: new Center(
     child: new Column(
      mainAxisSize: MainAxisSize.max, 
      mainAxisAlignment: MainAxisAlignment.center, 
      children: [ 
      new Radio<int>(
       value: 0, 
       groupValue: _radioValue, 
       onChanged: _handleRadioValue 
      ), 
      new Radio<int>(
       value: 1, 
       groupValue: _radioValue, 
       onChanged: _handleRadioValue 
      ), 
      new AnimatedBuilder(
       child: const Text('SUBMIT'), 
       animation: _controller, 
       builder: (BuildContext context, Widget child) { 
       return new RaisedButton(
        color: new ColorTween(
        begin: theme.primaryColor, 
        end: theme.disabledColor, 
       ).animate(_controller).value, 
        colorBrightness: Brightness.dark, 
        child: child, 
        onPressed: _radioValue == null ? 
          null : 
          () => print('submit') 
       ); 
       } 
      ) 
      ], 
     ), 
    ), 
    ); 
    } 

    @override 
    void dispose() { 
    _controller.dispose(); 
    super.dispose(); 
    } 
}