还有另一种方法来做到这一点-只是使用FloatingActionButton适当的圆形按钮。

Scaffold(
      appBar: AppBar(
        title: const Text('Floating Action Button'),
      ),
      body: const Center(child: Text('Press the button below!')),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          // Add your onPressed code here!
        },
        backgroundColor: Colors.green,
        child: const Icon(Icons.navigation),
      ),
    )

你可以使用下面的代码:

ElevatedButton(
      onPressed: () {},
      style: ElevatedButton.styleFrom(
        shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.all(Radius.circular(borderRadius))),
      ),
      child: Text("ok"),
    )

addButton() {
return Row(
  mainAxisAlignment: MainAxisAlignment.center,
  children: <Widget>[
    Padding(
      padding: const EdgeInsets.symmetric(vertical: 10.0),
      child: SizedBox(
        height: 45,
        width: 200,
        child: ElevatedButton.icon(
          onPressed: () async {},
          style: ButtonStyle(
            shape: MaterialStateProperty.all<RoundedRectangleBorder>(
                RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(30.0),
                  )),
            elevation: MaterialStateProperty.all(1),
            backgroundColor: MaterialStateProperty.all(Colors.blue),
          ),
          icon: Icon(Icons.add, size: 18),
          label: Text("Add question"),
        ),
      ),
    ),
  ],
);

}

创建圆角按钮的不同方法如下:

用ElevatedButton. stylefrom

ElevatedButton(
          style: ElevatedButton.styleFrom(
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(30.0),
            ),
          ),
          onPressed: () {},
          child:
              Text("Buy now".toUpperCase(), style: TextStyle(fontSize: 14)),
        ),

用ButtonStyle提升按钮

ElevatedButton(
          style: ButtonStyle(
              shape: MaterialStateProperty.all<RoundedRectangleBorder>(
                  RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(50.0),
          ))),
          onPressed: () {},
          child: Text("Submit".toUpperCase()),
        ),

圆形按钮的实际演示可以在下面的Dartpad链接中找到:

圆形按钮演示例子在达特pad

另一个很酷的解决方案在2021年也适用:

TextButton(
    child: Padding(
        padding: const EdgeInsets.all(5.0),
        child: Text('Follow Us'.toUpperCase()),
    ),
    style: TextButton.styleFrom(
        backgroundColor: Colors.amber,
        shadowColor: Colors.red,
        elevation: 2,
        textStyle: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
        shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(5.0),)
    ),
    onPressed: () {
        print('Pressed');
    },
),

现在我们有一个图标按钮来实现圆形按钮点击和覆盖。但是，背景颜色还不可用，但同样可以通过Circle头像小部件实现，如下所示:

CircleAvatar(
    backgroundColor: const Color(0xffF4F3FA),
    child: IconButton(
        onPressed: () => FlushbarHelper.createInformation(
                             message: 'Work in progress...')
                             .show(context),
        icon: Icon(Icons.more_vert),
    ),
),