add: 百格齐放 (#10)

Author: chengxushi

2 - 百格齐放 - 20201202/yifang_main.dart

@@ -0,0 +1,180 @@
+import 'dart:math' as math;
+
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+
+void main() {
+  runApp(MyApp());
+}
+
+class MyApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Flutter Demo',
+      home: HomePage(),
+    );
+  }
+}
+
+class HomePage extends StatefulWidget {
+  @override
+  HomePageState createState() => HomePageState();
+}
+
+class HomePageState extends State<HomePage> {
+  List<int> upRatio = <int>[2, 5, 8, 3, 6, 9, 1, 4, 7];
+  List<List<int>> radioList = [];
+  int belowCount = 7;
+
+  @override
+  void initState() {
+    super.initState();
+    //初始化比例数组
+    for (final int radio in upRatio) {
+      radioList.add(<int>[radio, 10 - radio]);
+    }
+  }
+
+  @override
+  void dispose() {
+    super.dispose();
+  }
+
+  List<Widget> _upList() {
+    //支持总条数为 m，且每条比例条的区域数为 n 的比例条，并要求每个区域的比例均可以通过数组控制；
+
+    final List<Widget> tList = [];
+    for (final List<int> list in radioList) {
+      tList.add(
+        Expanded(
+          child: Column(
+            children: _item(list),
+          ),
+        ),
+      );
+    }
+    return tList;
+  }
+
+  List<Widget> _item(List<int> list) {
+    final List<Widget> itemList = [];
+    for (int i = 0; i < list.length; i++) {
+      itemList.add(
+        Expanded(
+          child: Container(
+            color: RandomColor.getColor(),
+            child: Align(
+              alignment: Alignment.center,
+              child: Text(
+                list[i].toString(),
+              ),
+            ),
+          ),
+          flex: list[i],
+        ),
+      );
+    }
+    return itemList;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: Flex(
+        direction: MediaQuery.of(context).orientation == Orientation.portrait ? Axis.vertical : Axis.horizontal,
+        children: [
+          Expanded(
+            child: Row(
+              children: _upList(),
+            ),
+          ),
+          Expanded(
+            child: LayoutBuilder(
+              builder: (BuildContext context, BoxConstraints constraints) {
+                print('maxHeight: ${constraints.maxHeight}');
+                print('maxWidth: ${constraints.maxWidth}');
+                return CustomPaint(
+                  size: Size(constraints.maxWidth, constraints.maxHeight),
+                  painter: SPainter(belowCount),
+                );
+              },
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class RandomColor {
+  const RandomColor._();
+
+  static final math.Random _random = math.Random();
+
+  static Color getColor() {
+    return Color.fromARGB(
+      255,
+      _random.nextInt(255),
+      _random.nextInt(255),
+      _random.nextInt(255),
+    );
+  }
+}
+
+class SPainter extends CustomPainter {
+  SPainter(this.count);
+
+  int count;
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    final Paint paint = Paint()
+      ..style = PaintingStyle.stroke
+      ..color = Colors.black
+      ..strokeWidth = 1.0
+      ..isAntiAlias = true;
+
+    final double h = size.height;
+    final double w = size.width;
+    final double divWidth = w / (count + 1);
+    final double divHeight = h / (count + 1);
+    // //辅助线
+    // for(int i = 1; i <= count; i++){
+    //   final double dy = divHeight * i;
+    //   canvas.drawLine(Offset(0, dy), Offset(w, dy), paint);
+    // }
+    // for(int i = 1; i <= count; i++){
+    //   final double dx = divWidth * i;
+    //   canvas.drawLine(Offset(dx, 0), Offset(dx, h), paint);
+    // }
+    paint.style = PaintingStyle.fill;
+    //从左上到右下
+    for (int i = 1; i <= count; i++) {
+      paint.color = RandomColor.getColor();
+      canvas.drawRect(
+        Rect.fromCenter(
+          center: Offset(divWidth * i, divHeight * i),
+          width: divWidth * 2,
+          height: divHeight * 2,
+        ),
+        paint,
+      );
+    }
+    //从右上到左下
+    for (int i = 1; i <= count; i++) {
+      paint.color = RandomColor.getColor();
+      canvas.drawRect(
+        Rect.fromCenter(
+          center: Offset(divWidth * (count + 1 - i), divHeight * i),
+          width: divWidth * 2,
+          height: divHeight * 2,
+        ),
+        paint,
+      );
+    }
+  }
+
+  @override
+  bool shouldRepaint(covariant CustomPainter oldDelegate) => true;
+}