books

assets/draw/p06/s04.dart

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+
+
+import 'package:flutter/material.dart';
+
+import '../components/coordinate.dart';
+
+
+/// create by 张风捷特烈 on 2020/5/1
+/// contact me by email 1981462002@qq.com
+/// 说明:
+
+class Paper extends StatelessWidget {
+  const Paper({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      color: Colors.white,
+      child: CustomPaint(
+        // 使用CustomPaint
+        painter: PaperPainter(),
+      ),
+    );
+  }
+}
+
+class PaperPainter extends CustomPainter {
+
+
+  final Coordinate coordinate= Coordinate();
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    coordinate.paint(canvas, size);
+    canvas.translate(size.width / 2, size.height / 2);
+
+    Path path = Path();
+    Paint paint = Paint();
+    paint
+      ..color = Colors.purple
+      ..style = PaintingStyle.fill;
+    path
+      ..relativeMoveTo(0, 0)
+      ..relativeLineTo(-30, 120)
+      ..relativeLineTo(30, -30)
+      ..relativeLineTo( 30,30)
+      ..close();
+
+
+    var pathOval =Path()..addOval(Rect.fromCenter(center: Offset(0, 0),width: 60,height: 60));
+    canvas.drawPath(Path.combine(PathOperation.difference, path, pathOval), paint);
+
+    canvas.translate(120, 0);
+    canvas.drawPath(Path.combine(PathOperation.intersect, path, pathOval), paint);
+
+    canvas.translate(120, 0);
+    canvas.drawPath(Path.combine(PathOperation.union, path, pathOval), paint);
+
+    canvas.translate(-120*3.0, 0);
+    canvas.drawPath(Path.combine(PathOperation.reverseDifference, path, pathOval), paint);
+
+    canvas.translate(-120, 0);
+    canvas.drawPath(Path.combine(PathOperation.xor, path, pathOval), paint);
+  }
+
+  @override
+  bool shouldRepaint(CustomPainter oldDelegate) => false;
+}