Container 控件設置漸變色問題

body:Center(
  child: Container(
    color: Colors.blue,
    width: 400,
    height: 200,
    decoration:new BoxDecoration(
      gradient: const LinearGradient(
          colors: [
        Colors.amber,
        Colors.cyanAccent
      ])
    )
  ),
)

如上面寫法，在調試的時候會出現下面的報錯。

Cannot provide both a color and a decoration
The color argument is just a shorthand for "decoration: new BoxDecoration(color: color)".
'package:flutter/src/widgets/container.dart':
Failed assertion: line 319 pos 15: 'color == null || decoration == null'

報錯中告訴我們color屬性和decoration 是不能同時存在的，一次我們需要把color移除即可。