你如何改变 TextButton flutter 上的字体大小

How do you change the font size on a TextButton flutter

这里你会改变这个例子中Hello World的字体大小吗? 尝试了字体样式等但出现错误,请问我错过了什么?

new TextButton(
      style: ButtonStyle(
        foregroundColor: MaterialStateProperty.all<Color>(Colors.white.withOpacity(0.7)),
        overlayColor: MaterialStateProperty.resolveWith<Color>(
                (Set<MaterialState> states) {
              if (states.contains(MaterialState.focused) ||
                    states.contains(MaterialState.pressed))
                  return Colors.red.withOpacity(0.7);
                return Colors.red;
              return Colors.white70; // Defer to the widget's default.
            }
        ),
      ),
      child: new Text('Hello World'),

请试用

TextButton(
            style: ButtonStyle(
              foregroundColor: MaterialStateProperty.all<Color>(
                  Colors.white.withOpacity(0.7)),
              overlayColor: MaterialStateProperty.resolveWith<Color>(
                  (Set<MaterialState> states) {
                if (states.contains(MaterialState.focused) ||
                    states.contains(MaterialState.pressed))
                  return Colors.red.withOpacity(0.7);
                return Colors.red; // Defer to the widget's default.
              return Colors.white70;
              }),
            ),
            child: new Text('Hello World', style: TextStyle( fontSize: 30),),
          )
SizedBox(

height:100,
width:100,
new TextButton(
      style: ButtonStyle(
        foregroundColor: MaterialStateProperty.all<Color>(Colors.white.withOpacity(0.7)),
        overlayColor: MaterialStateProperty.resolveWith<Color>(
                (Set<MaterialState> states) {
              if (states.contains(MaterialState.focused) ||
                    states.contains(MaterialState.pressed))
                  return Colors.red.withOpacity(0.7);
                return Colors.red;
              return Colors.white70; // Defer to the widget's default.
            }
        ),
      ),
    child: new Text('Hello World', style: TextStyle( fontSize: 30),

) )