可更改容器背景颜色/颤动颜色的按钮

Question

我是flutter的新手，我只是在学习flutter的所有基础知识。我偶然发现了按钮小部件和按下的函数，我创建了一个简单的容器，里面有一个按钮，如下所示

这是容器

Container(

    child: Padding(
    padding: const EdgeInsets.only(top: 25.0, left: 30),
    child: Text("Item 1", style: TextStyle(
    color: Colors.lightBlueAccent,
    fontWeight: FontWeight.bold,
    fontSize: 20,
            ),
           ),
          ),

这是按钮

child: FloatingActionButton(

     onPressed(){},
    child: Text("+", style: TextStyle(
    fontSize: 20,
                 ),
                ),
    backgroundColor: Colors.lightBlue,

               ),

我想让按钮具有将容器背景更改为某种颜色的功能，例如蓝色。但是我想我在网上找不到答案。有没有我可以应用的方法或者我不知道存在的代码？

提前感谢！！

Answer 1

虽然你已经从jitsm555得到了一个很好的答案，但这里仍然是完整的例子，我希望这对你有进一步的帮助。

import 'package:flutter/material.dart';

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

class ColorChange extends StatefulWidget {
  @override
  _ColorChangeState createState() => _ColorChangeState();
}

class _ColorChangeState extends State<ColorChange> {
  //Initially color is set to yellow which will be changed when button is pressed
  Color color = Colors.yellow;
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text("Change Container Color"),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Container(
                width: 300,
                height: 300,
                color: color, //value of color which we will change by pressing buttons
              ),

             /* Below Row of Button when pressed will fire up 
                the setState and the state of our default color variable will 
                change according to Button which is pressed
             */
              Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[
                  RaisedButton(
                    color: Colors.red,
                    child: Text("Red"),
                    onPressed: () {
                      setState(() {
                        color = Colors.red;
                      });
                    },
                  ),
                  RaisedButton(
                    color: Colors.green,
                    child: Text("Green"),
                    onPressed: () {
                      setState(() {
                        color = Colors.green;
                      });
                    },
                  ),
                  RaisedButton(
                    color: Colors.blue,
                    child: Text("Blue"),
                    onPressed: () {
                      setState(() {
                        color = Colors.blue;
                      });
                    },
                  ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}

输出：

​

​

Answer 2

声明默认材质颜色

MaterialColor _color = Colors.green;

在onPressed()中更改上面的颜色

Container(
        color: _color,
        child: RaisedButton(onPressed: () {
          setState(() {
            _color = Colors.blue; // This change Container color
          });
        }),
      )