您可以简单地使用RaisedButton

Padding(
  padding: EdgeInsets.only(left: 150.0, right: 0.0),
  child: RaisedButton(
    textColor: Colors.white,
    color: Colors.black,
    child: Text("Search"),
    onPressed: () {},
    shape: new RoundedRectangleBorder(
      borderRadius: new BorderRadius.circular(30.0),
    ),
  ),
)

输出:

更多信息:RSCoder

RaisedButton(
          child: Text("Button"),
          onPressed: (){},
          shape: RoundedRectangleBorder(borderRadius: new BorderRadius.circular(30.0),
          side: BorderSide(color: Colors.red))
        )

这里有另一个解决方案:

Container(
    height: MediaQuery.of(context).size.height * 0.10,
    width: MediaQuery.of(context).size.width,
    child: ButtonTheme(
        minWidth: MediaQuery.of(context).size.width * 0.75,
        child: RaisedButton(
            shape: RoundedRectangleBorder(
                borderRadius: new BorderRadius.circular(25.0),
                side: BorderSide(color: Colors.blue)),
                onPressed: () async {
                    // Do something
                },
                color: Colors.red[900],
                textColor: Colors.white,
                child: Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: Text("Button Text,
                    style: TextStyle(fontSize: 24)),
            ),
        ),
    ),
),

试试这个:

SizedBox(
  height: 40.0,
  child: MaterialButton(
    child: Text("Button"),
    color: Colors.blue,
    disabledColor: Colors.blue,
    shape: RoundedRectangleBorder(
      borderRadius: BorderRadius.all(
        Radius.circular(10.0), // Change your border radius here
      ),
    ),
    onPressed: () {},
  ),
),

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');
    },
),

1. 解决方案概述

FlatButton和RaisedButton已弃用。

因此，你可以使用形状放在样式属性，为TextButton和ElevatedButton。

自Flutter 2.0以来有一些变化:

style:属性类型已更改为ButtonStyle shape:属性类型已更改为MaterialStateProperty<T>

2. 圆形的按钮

在style属性中存在shape属性:

style: ButtonStyle(
  shape: MaterialStateProperty.all<RoundedRectangleBorder>(
    RoundedRectangleBorder(
      borderRadius: BorderRadius.circular(18.0),
      side: BorderSide(color: Colors.red)
    )
  )
)

方形按钮

对于方形按钮，您可以使用ElevatedButton或添加其他方式:

style: ButtonStyle(
  shape: MaterialStateProperty.all<RoundedRectangleBorder>(
    RoundedRectangleBorder(
      borderRadius: BorderRadius.zero,
      side: BorderSide(color: Colors.red)
    )
  )
)

完整的示例

Row(
  mainAxisAlignment: MainAxisAlignment.end,
  children: [
    TextButton(
      child: Text(
        "Add to cart".toUpperCase(),
        style: TextStyle(fontSize: 14)
      ),
      style: ButtonStyle(
        padding: MaterialStateProperty.all<EdgeInsets>(EdgeInsets.all(15)),
        foregroundColor: MaterialStateProperty.all<Color>(Colors.red),
        shape: MaterialStateProperty.all<RoundedRectangleBorder>(
          RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(18.0),
            side: BorderSide(color: Colors.red)
          )
        )
      ),
      onPressed: () => null
    ),
    SizedBox(width: 10),
    ElevatedButton(
      child: Text(
        "Buy now".toUpperCase(),
        style: TextStyle(fontSize: 14)
      ),
      style: ButtonStyle(
        foregroundColor: MaterialStateProperty.all<Color>(Colors.white),
        backgroundColor: MaterialStateProperty.all<Color>(Colors.red),
        shape: MaterialStateProperty.all<RoundedRectangleBorder>(
          RoundedRectangleBorder(
            borderRadius: BorderRadius.zero,
            side: BorderSide(color: Colors.red)
          )
        )
      ),
      onPressed: () => null
    )
  ]
)