如何在Flutter上为MaterialButton设置圆角边框？

Question

我正在尝试将圆角边框设置为我的圆角边框MaterialButton，要设置RoundedRectangleBorder形状属性的MaterialButton，问题是它没有效果。

码：

  Widget _showNeedHelpButton() {
    return new Padding(      
      padding: EdgeInsets.fromLTRB(0.0, 5.0, 0.0, 0.0),
      child: new MaterialButton(
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(20.0))),
        elevation: 5.0,
        minWidth: 200.0,
        height: 35,
        color: Color(0xFF801E48),
        child: new Text('Preciso de ajuda',
            style: new TextStyle(fontSize: 16.0, color: Colors.white)),
        onPressed: () {
          setState(() {
            _isNeedHelp = true;
          });
        },
      ),
    );
  }

结果：

Answer 1

MaterialButton(
        child: Text('My Button'),
        height: 40,
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(10.0),
        ),
)

RoundedRectangleBorder 会帮助你https://api.flutter.dev/flutter/painting/RoundedRectangleBorder-class.html

Answer 2

如果需要使用MaterialButton()-您需要使用MaterialWidget 扭曲按钮以获得所需的行为。

    Widget _showNeedHelpButton() {
    return Padding(
      padding: EdgeInsets.fromLTRB(0.0, 5.0, 0.0, 0.0),
      child: Material(  //Wrap with Material
        shape: RoundedRectangleBorder(borderRadius:BorderRadius.circular(22.0) ),
        elevation: 18.0,
        color: Color(0xFF801E48),
        clipBehavior: Clip.antiAlias, // Add This
        child: MaterialButton(
          minWidth: 200.0,
          height: 35,
          color: Color(0xFF801E48),
          child: new Text('Preciso de ajuda',
              style: new TextStyle(fontSize: 16.0, color: Colors.white)),
          onPressed: () {
//          setState(() {
//            _isNeedHelp = true;
//          });
          },
        ),
      ),
    );
  }

输出：

更新：

  minWidth: 200.0,
  height: 95,