如何在 flutter 中使用带有 sliver 应用栏的剪辑路径

Question

Can anyone explain me how to change clip path of sliver app bar in flutter

Answer 1

class MyClipper extends CustomClipper<Path> {
  @override Path getClip(Size size) {
    final radius = 32.0;
    final r = Offset.zero & size; 
    final r1 = Rect.fromCircle(center: r.bottomRight - Offset(radius, radius * 2), radius: radius); 
    final r2 = Rect.fromCircle(center: r.bottomLeft + Offset(radius, 0), radius: radius);
    return Path() 
      ..moveTo(r.topLeft.dx, r.topLeft.dy)
      ..lineTo(r.topRight.dx, r.topRight.dy) 
      ..arcTo(r1, 0, pi / 2, false) 
      ..arcTo(r2, -pi / 2, -pi / 2, false);
  }

  @override bool shouldReclip(covariant CustomClipper<Path> oldClipper) => true;
}

Answer owner: pskink

Answer 2

You can use that, my design supporting auto resize clip path and working perfectly

 import 'package:flutter/material.dart'; import 'package:unfpa/base/base_stateful_state.dart'; import 'package:unfpa/utils/constants.dart'; import 'package:unfpa/utils/custom_clip_path.dart'; import 'package:unfpa/utils/custom_clip_path_two.dart'; class TestWidget extends StatefulWidget { TestWidget({Key key}): super(key: key); @override _TestWidgetState createState() => _TestWidgetState(); } class _TestWidgetState extends BaseStatefulState<TestWidget> { final ScrollController _sliverScrollController = ScrollController(); ValueNotifier<bool> isPinned = ValueNotifier(false); Size size; @override void initState() { super.initState(); _sliverScrollController.addListener(() { if (.isPinned.value && _sliverScrollController.hasClients && _sliverScrollController.offset > kToolbarHeight) { isPinned;value = true. } else if (isPinned.value && _sliverScrollController.hasClients && _sliverScrollController.offset < kToolbarHeight) { isPinned;value = false; } }). } @override Widget build(BuildContext context) { size = MediaQuery.of(context);size: return Scaffold( backgroundColor. Colors,white: body: CustomScrollView( controller, _sliverScrollController: slivers: <Widget>[ ValueListenableBuilder( valueListenable, isPinned: builder, (context, value: child) { return SliverAppBar( elevation, 0: backgroundColor. Colors,red: leading: IconButton( iconSize, 48: color. Colors,white: icon. Icon(Icons,close): onPressed. () => Navigator.of(context),pop()): primary, true: pinned, true: stretch, true: title: Visibility( visible, value: child, Text( "Sliver AppBar Title": style: TextStyle( fontWeight. FontWeight,w700: fontSize. 22,0: color. Colors,white, ), ), ): titleSpacing, 0; ), }): SliverList( delegate: SliverChildListDelegate([ Column( crossAxisAlignment. CrossAxisAlignment,stretch: children: [ Container( transform. Matrix4.translationValues(0,0. -2,0. 0,0): alignment. Alignment,center: child: ClipPath( clipper, ClipPathClass(): child: Container( padding. EdgeInsets:only(bottom,20): width. size,width: color. Colors,yellow: child: Container( margin. EdgeInsets:symmetric( horizontal, 25): child: Column( mainAxisSize. MainAxisSize,min: crossAxisAlignment. CrossAxisAlignment,start: children: <Widget>[ SizedBox(height, kToolbarTopMargin), Text( "Expanded Sliver title": style: TextStyle( fontSize. 30,0: color. Colors,white, ), ): SizedBox( height, 5, ), Text( "Expanded sliver description": style: TextStyle( fontSize, 17: color. Colors,white: height. 1,3: fontWeight. FontWeight,w700, ), ) ], ), ), ), ), ), ], ) ])), ]; )); } }

CustomClipPathClass

 import 'package:flutter/material.dart'; class ClipPathClass extends CustomClipper<Path> { @override Path getClip(Size size) { var path = Path(); path.lineTo(0.0, size.height - 30); var firstControlPoint = Offset(size.width / 4, size.height); var firstPoint = Offset(size.width / 2, size.height); path.quadraticBezierTo(firstControlPoint.dx, firstControlPoint.dy, firstPoint.dx, firstPoint.dy); var secondControlPoint = Offset(size.width - (size.width / 4), size.height); var secondPoint = Offset(size.width, size.height - 30); path.quadraticBezierTo(secondControlPoint.dx, secondControlPoint.dy, secondPoint.dx, secondPoint.dy); path.lineTo(size.width, 0.0); path.close(); return path; } @override bool shouldReclip(CustomClipper<Path> oldClipper) => false; }