flutter 2.0版本新增了三个按钮
TextButton、OutlinedButton、ElevatedButton
以TextButton为例：
属性：
const TextButton({Key? key,required VoidCallback? onPressed,VoidCallback? onLongPress,ButtonStyle? style,FocusNode? focusNode,bool autofocus = false,Clip clipBehavior = Clip.none,required Widget child,}) : super(key: key,onPressed: onPressed,onLongPress: onLongPress,style: style,focusNode: focusNode,autofocus: autofocus,clipBehavior: clipBehavior,child: child,);当想改变按钮圆角时需要在style中设置，看一下style属性里有什么？
style属性
class ButtonStyle with Diagnosticable {/// Create a [ButtonStyle].const ButtonStyle({this.textStyle,this.backgroundColor,this.foregroundColor,this.overlayColor,this.shadowColor,this.elevation,this.padding,this.minimumSize,this.side,this.shape,this.mouseCursor,this.visualDensity,this.tapTargetSize,this.animationDuration,this.enableFeedback,this.alignment,});其中side控制边框final MaterialStateProperty<BorderSide?>? side;
使用：
side: MaterialStateProperty.all(BorderSide(color: Colors.blue,width: 4),)其中shape可以包含side的作用，作用范围比side广，这里使用shape时
/// The shape of the button's underlying [Material].////// This shape is combined with [side] to create a shape decorated/// with an outline.final MaterialStateProperty<OutlinedBorder?>? shape;用到MaterialStateProperty<OutlinedBorder?>这个OutlinedBorder是个抽象类，不能直接使用，直接使用会报错，需要用它的子类，这里可以使用：RoundedRectangleBorder
style: ButtonStyle(shape: MaterialStateProperty.all(RoundedRectangleBorder(side: BorderSide(width: 0.5,color: Color(0xFFB4B4B4),),borderRadius: BorderRadius.circular(20),),),// side: MaterialStateProperty.all(// BorderSide(// color: Colors.blue,// width: 4),// )),
截屏2021-03-20 15.32.52.png