绘制点集

lib/main.dart

@@ -3,6 +3,7 @@ import 'package:flutter/material.dart';
 import 'counter/counter_page.dart';
 import 'guess/guess_page.dart';
 import 'muyu/muyu_page.dart';
+import 'paper/paper.dart';
 
 void main() {
   runApp(const MyApp());
@@ -19,7 +20,7 @@ class MyApp extends StatelessWidget {
       theme: ThemeData(
         primarySwatch: Colors.blue,
       ),
-      home: const MuyuPage(),
+      home: const Paper(),
     );
   }
 }

lib/paper/paper.dart

@@ -0,0 +1,51 @@
+import 'dart:ui';
+
+import 'package:flutter/material.dart';
+
+
+import 'paper_app_bar.dart';
+
+class Paper extends StatefulWidget {
+  const Paper({Key? key}) : super(key: key);
+
+  @override
+  State<Paper> createState() => _PaperState();
+}
+
+class _PaperState extends State<Paper> {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: PaperAppBar(onClear: _clear,),
+      body: CustomPaint(
+        painter: PaperPainter(),
+        child: ConstrainedBox(constraints: const BoxConstraints.expand()),
+      ),
+    );
+  }
+
+  void _clear() {
+
+  }
+}
+
+class PaperPainter extends CustomPainter{
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    List<Offset> points = const [
+      Offset(100,100),
+      Offset(100,150),
+      Offset(150,150),
+      Offset(200,100),
+    ];
+
+    Paint paint = Paint();
+    paint.strokeWidth = 10;
+    canvas.drawPoints(PointMode.polygon, points , paint);
+  }
+
+  @override
+  bool shouldRepaint(covariant CustomPainter oldDelegate) => true;
+
+}

lib/paper/paper_app_bar.dart

@@ -0,0 +1,41 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+class PaperAppBar extends StatelessWidget implements PreferredSizeWidget {
+  final VoidCallback onClear;
+
+  const PaperAppBar({
+    Key? key,
+    required this.onClear,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return AppBar(
+      centerTitle: true,
+      elevation: 0,
+      systemOverlayStyle: const SystemUiOverlayStyle(
+          statusBarIconBrightness: Brightness.dark,
+          statusBarColor: Colors.transparent),
+      backgroundColor: Colors.white,
+      title: Text(
+        '画板绘制',
+        style: TextStyle(color: Colors.black, fontSize: 16),
+      ),
+      actions: [
+        IconButton(
+            splashRadius: 20,
+            onPressed: onClear,
+            icon: Icon(
+              CupertinoIcons.delete,
+              color: Colors.black,
+              size: 20,
+            ))
+      ],
+    );
+  }
+
+  @override
+  Size get preferredSize => const Size.fromHeight(kToolbarHeight);
+}