做到这一点的方法之一是定义buttonTheme在theme中MaterialApp：

例如：

void main() {
  runApp(MaterialApp(
    home: Home(),
    theme: ThemeData(
        accentColor: Colors.redAccent,
        buttonTheme: ButtonThemeData(
           buttonColor: Colors.blueAccent,
           shape: RoundedRectangleBorder(),
           textTheme: ButtonTextTheme.accent,
           ....
    )),
  ));
}

class Home extends StatelessWidget {
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
          title: Text("Button Theme"),
          backgroundColor: Colors.green),
      body: Center(
          child: RaisedButton( //Button Color is as define in theme
        onPressed: () {},
        child: Text("Send"), //Text Color as define in theme
      )),
    );
  }
}

与此相关的所有在此下定义的按钮MaterialApp都将采用此主题样式。

文字颜色将是我accentColor定义的中的ThemeData定义，textTheme: ButtonTextTheme.accent因此它将选择accentColor

按中定义的按钮选择主题样式 theme