forked from lxm_flutter/FlutterUnit
82 lines
1.8 KiB
Dart
82 lines
1.8 KiB
Dart
import 'dart:math';
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import 'package:flutter/material.dart';
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/// create by 张风捷特烈 on 2020-04-19
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/// contact me by email 1981462002@qq.com
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/// 说明:
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// {
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// "widgetId": 85,
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// "name": 'Align其他用法',
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// "priority": 2,
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// "subtitle":
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// "由于Alignment对象可指定在父容器中宽高的分率位置\n"
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// "可以使用Align实现一些复杂的排布需求，比如按指定的数学方程变化位置",
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// }
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class Ball extends StatelessWidget {
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Ball({
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Key key,
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this.radius = 15,
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this.color = Colors.blue,
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}) : super(key: key);
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final double radius; //半径
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final Color color; //颜色
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@override
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Widget build(BuildContext context) {
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return Container(
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width: radius * 2,
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height: radius * 2,
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decoration: BoxDecoration(
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shape: BoxShape.circle,
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color: color,
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),
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);
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}
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}
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class SinLayout extends StatefulWidget {
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SinLayout({
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Key key,
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}) : super(key: key);
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@override
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_SinLayoutState createState() => _SinLayoutState();
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}
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class _SinLayoutState extends State<SinLayout> {
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var _x = 0.0; //Alignment坐标系上的x坐标
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@override
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Widget build(BuildContext context) {
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var item = Container(
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width: 300,
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height: 120,
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color: Colors.black.withAlpha(10),
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child: Align(
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child: Ball(
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color: Colors.orangeAccent,
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),
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alignment: Alignment(_x, f(_x * pi)),
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),
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);
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var slider = Slider(
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max: 180,
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min: -180,
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divisions: 360,
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label: "${_x.toStringAsFixed(2)}π",
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value: _x * 180,
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onChanged: (v) => setState(() => _x = v / 180));
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return Column(
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mainAxisSize: MainAxisSize.min,
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children: <Widget>[slider, item],
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);
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}
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double f(x) {
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//映射函数 -- 可随意指定
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double y = sin(x);
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return y;
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}
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}
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