你可以简单地使用RaisedButton或你可以使用InkWell来获得一个自定义按钮和属性，如onDoubleTap, onLongPress等:

new InkWell(
  onTap: () => print('hello'),
  child: new Container(
    //width: 100.0,
    height: 50.0,
    decoration: new BoxDecoration(
      color: Colors.blueAccent,
      border: new Border.all(color: Colors.white, width: 2.0),
      borderRadius: new BorderRadius.circular(10.0),
    ),
    child: new Center(child: new Text('Click Me', style: new TextStyle(fontSize: 18.0, color: Colors.white),),),
  ),
),

如果你想在InkWell小部件中使用splashColor和highlightColor属性，使用Material小部件作为InkWell小部件的父部件，而不是装饰容器(删除装饰属性)。在这里阅读原因。

创建圆角按钮最简单的方法之一是使用FlatButton，然后通过设置其shape属性指定圆度。遵循下面的代码

FlatButton ( 填充:EdgeInsets.all (30.0), 颜色:Colors.black, 形状:RoundedRectangleBorder ( borderRadius: BorderRadius.circular (20.0)), child: child: Text( “按钮”, TextStyle(颜色:Colors.white)， ), onPressed:() { 打印(“按钮按下”); }, ),

注意:为了改变圆度，调整BorderRadius.circular()中的值

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');
    },
),

更新

由于左侧按钮现在已弃用，请使用右侧按钮。

Deprecated    -->   Recommended

RaisedButton  -->   ElevatedButton
OutlineButton -->   OutlinedButton
FlatButton    -->   TextButton

ElevatedButton

Using StadiumBorder ElevatedButton( onPressed: () {}, child: Text('Button'), style: ElevatedButton.styleFrom(shape: StadiumBorder()), ) Using RoundedRectangleBorder ElevatedButton( onPressed: () {}, child: Text('Button'), style: ElevatedButton.styleFrom( shape: RoundedRectangleBorder( borderRadius: BorderRadius.circular(12), // <-- Radius ), ), ) Using CircleBorder ElevatedButton( onPressed: () {}, child: Text('Button'), style: ElevatedButton.styleFrom( shape: CircleBorder(), padding: EdgeInsets.all(24), ), ) Using BeveledRectangleBorder ElevatedButton( onPressed: () {}, child: Text('Button'), style: ElevatedButton.styleFrom( shape: BeveledRectangleBorder( borderRadius: BorderRadius.circular(12) ), ), )

OutlinedButton

Using StadiumBorder OutlinedButton( onPressed: () {}, child: Text('Button'), style: OutlinedButton.styleFrom( shape: StadiumBorder(), ), ) Using RoundedRectangleBorder OutlinedButton( onPressed: () {}, child: Text('Button'), style: OutlinedButton.styleFrom( shape: RoundedRectangleBorder( borderRadius: BorderRadius.circular(12), ), ), ) Using CircleBorder: OutlinedButton( onPressed: () {}, child: Text('Button'), style: OutlinedButton.styleFrom( shape: CircleBorder(), padding: EdgeInsets.all(24), ), ) Using BeveledRectangleBorder OutlinedButton( onPressed: () {}, child: Text('Button'), style: OutlinedButton.styleFrom( shape: BeveledRectangleBorder( borderRadius: BorderRadius.circular(12), ), ), )

TextButton

TextButton也类似于ElevatedButton和OutlinedButton，但是，你只能看到按钮按下的形状。

使用Flutter版本2，请尝试以下操作

ElevatedButton(
    style: ButtonStyle(
        shape: MaterialStateProperty.all<OutlinedBorder>(
            RoundedRectangleBorder(
                side:
                    BorderSide(width: 1.0, color: Colors.red,
                borderRadius:
                    BorderRadius.circular(5.0),),),
        backgroundColor: MaterialStateProperty.all<Color>(Colors.red),
        foregroundColor: MaterialStateProperty.all<Color>(Colors.green),
        elevation:
            MaterialStateProperty.all<double>(8.0),
        padding: MaterialStateProperty.all<EdgeInsetsGeometry>(
            const EdgeInsets.symmetric(
                horizontal: 15.0,
                vertical: 10.0),),),
    onPressed: (){},
    child: Text('Button'),)