Flutter跨平台移动端开发丨Container + FlatButton 实现背景色渐变的圆角Button

Container

Container 是各种我们已知的 widget 的组合，使用它可以实现装饰、变换、限制等各种效果

Container({
Key key,
this.alignment,
this.padding,
Color color,
Decoration decoration,
this.foregroundDecoration,
double width,
double height,
BoxConstraints constraints,
this.margin,
this.transform,
this.child,
}) : assert(margin == null || margin.isNonNegative),
assert(padding == null || padding.isNonNegative),
assert(decoration == null || decoration.debugAssertIsValid()),
assert(constraints == null || constraints.debugAssertIsValid()),
assert(color == null || decoration == null,
'Cannot provide both a color and a decoration\n'
'The color argument is just a shorthand for "decoration: new BoxDecoration(color: color)".'
),
decoration = decoration ?? (color != null ? BoxDecoration(color: color) : null),
constraints =
(width != null || height != null)