Flutter 通过Clipper实现各种自定义形状的示例代码

这篇文章主要介绍了Flutter 通过Clipper实现各种自定义形状的示例代码，文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值，需要的朋友们下面随着小编来一起学习学习吧

本文介绍了Flutter 通过Clipper实现各种自定义形状的示例代码，分享给大家，具体如下：

Clipoval 圆形裁剪

Clipoval( child: SizedBox( width: 120.0, height: 120.0, child: Image.asset( Config.assets_avatar_1, ), ), );

CircleAvatar 圆形头像

CircleAvatar( radius: 60.0, backgroundImage: Assetimage( Config.assets_avatar_1, ), );

Container decoration 装饰形状

 

通过BoxShape.circle实现圆形图片

Container( width: 120.0, height: 120.0, decoration: Boxdecoration( shape: BoxShape.circle, image: decorationImage( image: Assetimage( Config.assets_avatar_1, ), ), ) )；

通过BorderRadius实现圆形图片

Container( width: 120.0, height: 120.0, decoration: Boxdecoration( borderRadius: BorderRadius.all(Radius.circular(60.0)), image: decorationImage( image: Assetimage( Config.assets_avatar_1, ), ), ), )

ClipPath 路径剪裁

ClipPath( clipper: TriangleClipper(ClipperPosition.LeftTop), child: Container( width: 16.0, height: 16.0, decoration: Boxdecoration( color: Colors.blue, ), ), ); enum ClipperPosition { LeftTop, RightTop, } class TriangleClipper extends CustomClipper { final ClipperPosition position; TriangleClipper(this.position); @override Path getClip(Size size) { final path = Path(); path.lineto(0.0, 0.0); if (position == ClipperPosition.LeftTop) { path.lineto(size.width, 0.0); path.lineto(size.width, size.height); } else if (position == ClipperPosition.RightTop) { path.lineto(size.width, 0.0); path.lineto(0.0, size.height); } path.close(); return path; } @override bool shouldReclip(CustomClipper oldClipper) { return false; } }

ClipRect 矩形剪裁

Container( alignment: Alignment.topCenter, color: Colors.transparent, child: Container( color: Colors.green, child: ClipRect( clipper: _RectClipper(20.0), child: Image.asset( Config.assets_avatar_1, width: 160.0, height: 160.0, fit: BoxFit.fill, ), ), ), ); class _RectClipper extends CustomClipper { /// Remove side of size final double removeSize; _RectClipper(this.removeSize); @override Rect getClip(Size size) { return new Rect.fromLTRB( removeSize, removeSize, size.width - removeSize, size.height - removeSize, ); } @override bool shouldReclip(CustomClipper oldClipper) { return false; } }

ClipRRect 圆角矩形剪裁

ClipRRect( borderRadius: BorderRadius.all(Radius.circular(16.0)), child: Image.asset( Config.assets_avatar_1, fit: BoxFit.fill, width: 120.0, height: 120.0, ), );

Star rating(CustomPaint) 评分控件

评分控件 UI图

 

实现方案

使用CustomPaint结合ClipPath画出单个五角星；

使用Stack渲染两层画面

背景层，一排灰色五角星  前景层，一排亮色五角星，并使用ClipRect截取一定Width

实现代码

class StarratingDemo extends StatefulWidget { @override _StarratingDemoState createState() => _StarratingDemoState(); } class _StarratingDemoState extends State { /// ClipPath Star rating _buildClipPathStarrating(double rate, int count) { return Container( padding: EdgeInsets.fromLTRB(24.0, 16.0, 24.0, 0.0), child: StaticratingBar( size: 50.0, rate: rate, count: count, ), ); } @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( centerTitle: true, title: Text('Star rating'), ), body: ListView( physics: BouncingScrollPhysics(), children: [ // _buildClipPathStarrating(1.0, 1), _buildClipPathStarrating(0.5, 5), _buildClipPathStarrating(2.0, 5), _buildClipPathStarrating(3.0, 5), _buildClipPathStarrating(4.0, 5), _buildClipPathStarrating(5.0, 5), _buildClipPathStarrating(5.5, 6), SizedBox(height: 16.0), ], ), ); } } class StaticratingBar extends StatelessWidget { /// Number of stars final int count; /// Init rate final double rate; /// Size of the starts final double size; final Color colorLight; final Color colorDark; StaticratingBar({ this.rate = 5, this.colorLight = const Color(0xFF1E88E5), this.colorDark = const Color(0xFFEEEEEE), this.count = 5, this.size = 60, }); Widget buildDarkStar() { return SizedBox( width: size * count, height: size, child: CustomPaint( painter: _PainterStars( count: count, color: colorDark, strokeWidth: 0.0, size: this.size / 2, style: PaintingStyle.fill, ), ), ); } Widget buildLightStar() { return ClipRect( clipper: _ratingBarClipper(rate * size), child: SizedBox( height: size, width: size * count, child: CustomPaint( painter: _PainterStars( count: count, strokeWidth: 0.0, color: colorLight, size: this.size / 2, style: PaintingStyle.fill, ), ), ), ); } @override Widget build(BuildContext context) { return Stack( children: [ buildDarkStar(), buildLightStar(), ], ); } } class _ratingBarClipper extends CustomClipper { final double width; _ratingBarClipper(this.width); @override Rect getClip(Size size) { return Rect.fromLTRB(0.0, 0.0, width, size.height); } @override bool shouldReclip(_ratingBarClipper oldClipper) { return false; } } class _PainterStars extends CustomPainter { final double size; final int count; final Color color; final PaintingStyle style; final double strokeWidth; _PainterStars({ this.size, this.count, this.color, this.strokeWidth, this.style, }); double degree2Radian(int degree) { return (pi * degree / 180); } Path createStarPath(double radius, Path path) { double radian = degree2Radian(36); double radiusIn = (radius * sin(radian / 2) / cos(radian)) * 1.1; path.moveto((radius * cos(radian / 2)), 0.0); path.lineto( (radius * cos(radian / 2) + radiusIn * sin(radian)), (radius - radius * sin(radian / 2)), ); path.lineto( (radius * cos(radian / 2) * 2), (radius - radius * sin(radian / 2)), ); path.lineto( (radius * cos(radian / 2) + radiusIn * cos(radian / 2)), (radius + radiusIn * sin(radian / 2)), ); path.lineto( (radius * cos(radian / 2) + radius * sin(radian)), (radius + radius * cos(radian)), ); path.lineto((radius * cos(radian / 2)), (radius + radiusIn)); path.lineto( (radius * cos(radian / 2) - radius * sin(radian)), (radius + radius * cos(radian)), ); path.lineto( (radius * cos(radian / 2) - radiusIn * cos(radian / 2)), (radius + radiusIn * sin(radian / 2)), ); path.lineto(0.0, (radius - radius * sin(radian / 2))); path.lineto( (radius * cos(radian / 2) - radiusIn * sin(radian)), (radius - radius * sin(radian / 2)), ); path.lineto((radius * cos(radian / 2)), 0.0); return path; } @override void paint(Canvas canvas, Size size) { Paint paint = Paint(); paint.strokeWidth = strokeWidth; paint.color = color; paint.style = style; Path path = Path(); double offset = strokeWidth > 0 ? strokeWidth + 2 : 0.0; path = createStarPath(this.size - offset, path); for (int i = 0; i 0) { path = path.shift(Offset(offset, offset)); } path.close(); canvas.drawPath(path, paint); } @override bool shouldRepaint(_PainterStars oldDelegate) { return oldDelegate.size != this.size; } }

代码地址

https://github.com/smiling1990/FlutterClipper