110 lines
2.9 KiB
Dart
110 lines
2.9 KiB
Dart
import 'package:flutter/material.dart';
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import 'dart:ui' as ui;
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import 'dart:math';
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class RadarChart extends StatelessWidget {
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final List<List<double>> data; // 存储多个数据集
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final List<String> labels; // 每个角的标签
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final double maxValue; // 数据的最大值，用来统一尺度
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const RadarChart({
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Key? key,
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required this.data,
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required this.labels,
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this.maxValue = 100,
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}) : super(key: key);
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@override
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Widget build(BuildContext context) {
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return CustomPaint(
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size: Size(300, 300), // 图表的大小
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painter: RadarChartPainter(
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data: data,
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labels: labels,
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maxValue: maxValue,
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),
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);
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}
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}
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class RadarChartPainter extends CustomPainter {
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final List<List<double>> data;
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final List<String> labels;
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final double maxValue;
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RadarChartPainter({
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required this.data,
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required this.labels,
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required this.maxValue,
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});
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@override
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void paint(Canvas canvas, Size size) {
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Paint paintLine = Paint()
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..color = Colors.blue
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..style = PaintingStyle.stroke
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..strokeWidth = 2;
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Paint axisPaint = Paint()
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..color = Colors.grey.withOpacity(0.5)
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..strokeWidth = 1;
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double centerX = size.width / 2;
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double centerY = size.height / 2;
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double radius = size.width / 2;
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int numOfPoints = labels.length;
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// 绘制雷达图的轴线
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for (int i = 0; i < numOfPoints; i++) {
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double angle = (2 * pi / numOfPoints) * i;
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double x = centerX + radius * cos(angle);
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double y = centerY + radius * sin(angle);
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// 画轴线
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canvas.drawLine(Offset(centerX, centerY), Offset(x, y), axisPaint);
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// 绘制标签
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TextPainter tp = TextPainter(
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text: TextSpan(
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text: labels[i],
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style: TextStyle(color: Colors.black, fontSize: 12),
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),
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textDirection: ui.TextDirection.ltr,
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);
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tp.layout();
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tp.paint(canvas, Offset(x + 8, y - 8)); // 设置标签位置
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}
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// 绘制多个数据集
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for (int i = 0; i < data.length; i++) {
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Paint fillPaint = Paint()
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..color = Colors.primaries[i % Colors.primaries.length].withOpacity(0.3)
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..style = PaintingStyle.fill;
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Paint linePaint = Paint()
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..color = Colors.primaries[i % Colors.primaries.length]
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..style = PaintingStyle.stroke
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..strokeWidth = 2;
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List<Offset> points = [];
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for (int j = 0; j < numOfPoints; j++) {
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double angle = (2 * pi / numOfPoints) * j;
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double pointRadius = (data[i][j] / maxValue) * radius;
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double x = centerX + pointRadius * cos(angle);
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double y = centerY + pointRadius * sin(angle);
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points.add(Offset(x, y));
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}
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// 画出数据连接线
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Path path = Path()..addPolygon(points, true);
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canvas.drawPath(path, linePaint);
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canvas.drawPath(path, fillPaint);
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}
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}
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@override
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bool shouldRepaint(covariant CustomPainter oldDelegate) => true;
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}
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