Flutter中的剪裁

 

圆形剪裁(ClipOval)

 

new ClipOval(

    child: new SizedBox(

      100.0,

      height:100.0,

      child:  new Image.network("https://sfault-avatar.b0.upaiyun.com/206/120/2061206110-5afe2c9d40fa3_huge256",fit: BoxFit.fill,),

    ),

  ),

圆角矩形剪裁(ClipRRect)

 

new ClipRRect(

    borderRadius: new BorderRadius.all(

        new Radius.circular(10.0)),

    child:  new SizedBox(

      100.0,

      height:100.0,

      child:  new Image.network("https://sfault-avatar.b0.upaiyun.com/206/120/2061206110-5afe2c9d40fa3_huge256",fit: BoxFit.fill,),

    ),

  )

矩形剪裁(ClipRect)

这个控件需要定义clipper参数才能使用,不然没有效果。

class _MyClipper extends CustomClipper<Rect>{

  @override

  Rect getClip(Size size) {

    return new Rect.fromLTRB(10.0, 10.0, size.width - 10.0,  size.height- 10.0);

  }

  @override

  bool shouldReclip(CustomClipper<Rect> oldClipper) {

      return true;

  }

}

 

new ClipRect(

            clipper: new _MyClipper(),

            child:new SizedBox(

              100.0,

              height:100.0,

              child:  new Image.network("https://sfault-avatar.b0.upaiyun.com/206/120/2061206110-5afe2c9d40fa3_huge256",fit: BoxFit.fill,),

            ) ,

          ),

路径剪裁(ClipPath)

 

class _StarCliper extends CustomClipper<Path>{

  final double radius;

  _StarCliper({this.radius});

  /// 角度转弧度公式

  double degree2Radian(int degree) {

    return (Math.pi * degree / 180);

  }

  @override

  Path getClip(Size size) {

    double radius = this.radius;

    Path path = new Path();

    double radian = degree2Radian(36);// 36为五角星的角度

    double radius_in = (radius * Math.sin(radian / 2) / Math

        .cos(radian)); // 中间五边形的半径

    path.moveTo((radius * Math.cos(radian / 2)), 0.0);// 此点为多边形的起点

    path.lineTo((radius * Math.cos(radian / 2) + radius_in

        * Math.sin(radian)),

        (radius - radius * Math.sin(radian / 2)));

    path.lineTo((radius * Math.cos(radian / 2) * 2),

        (radius - radius * Math.sin(radian / 2)));

    path.lineTo((radius * Math.cos(radian / 2) + radius_in

        * Math.cos(radian / 2)),

        (radius + radius_in * Math.sin(radian / 2)));

    path.lineTo(

        (radius * Math.cos(radian / 2) + radius

            * Math.sin(radian)), (radius + radius

        * Math.cos(radian)));

    path.lineTo((radius * Math.cos(radian / 2)),

        (radius + radius_in));

    path.lineTo(

        (radius * Math.cos(radian / 2) - radius

            * Math.sin(radian)), (radius + radius

        * Math.cos(radian)));

    path.lineTo((radius * Math.cos(radian / 2) - radius_in

        * Math.cos(radian / 2)),

        (radius + radius_in * Math.sin(radian / 2)));

    path.lineTo(0.0, (radius - radius * Math.sin(radian / 2)));

    path.lineTo((radius * Math.cos(radian / 2) - radius_in

        * Math.sin(radian)),

        (radius - radius * Math.sin(radian / 2)));

    path.close();// 使这些点构成封闭的多边形

    return path;

  }

  @override

  bool shouldReclip(_StarCliper oldClipper) {

      return this.radius != oldClipper.radius;

  }

}

先定义好五角星的路径ClipRect,然后:

new ClipPath(

    clipper: new _StarCliper(radius: 50.0),

    child:new SizedBox(

      100.0,

      height:100.0,

      child:  new Image.network("https://sfault-avatar.b0.upaiyun.com/206/120/2061206110-5afe2c9d40fa3_huge256",fit: BoxFit.fill,),

    ) ,

  )

转载:https://segmentfault.com/a/1190000015149101?utm_source=index-hottest

原文地址:https://www.cnblogs.com/sundaysandroid/p/13554154.html