Flutter七日游第七天：2018-12-22 天气：雨-阴
零、前言
最后一天了,今天将把前六天的零碎知识整合起来,以及未涉及的零碎知识
最后会附上源码，在github,我按天分包稍微整理了一下，顺手Star一下吧
顺便提一下：Dart语法的相关测试在test包的base里(怕你们找不到)
与Android代码交互后感觉flutter还是蛮可以的，可惜没条件玩ios,不然岂不是可以通杀
(给我七天或许可以把ios跑一圈,以后有钱再说吧)
留图镇楼：分类效果和查询效果
| - | - |
|---|---|
一、字体图标的相关问题
1.字体图标：
字体图标放大不变形，又能改变颜色，主要根据
.ttf的字体，
然后图标算一个文字，根据unicode来对应图标,就可以用了。
Icon(Icons.android)也许你经常用，但内置图标有限，只能测试玩玩
实际上用还是需要自定义才行，前端的时候有字体图标，Flutter应该也行
//比如我们经常怎样用：
Icon(Icons.comment)
2.进入源码看看：
貌似都是静态常量，核心在unicode，如
0xe577,还有就是字体(MaterialIcons)
/// * [design.google.com/icons](https://design.google.com/icons/)
class Icons {
Icons._();
// Generated code: do not hand-edit.
// See https://github.com/flutter/flutter/wiki/Updating-Material-Design-Fonts
// BEGIN GENERATED
/// <i class="material-icons md-36">360</i> — material icon named "360".
static const IconData threesixty = IconData(0xe577, fontFamily: 'MaterialIcons');
/// <i class="material-icons md-36">3d_rotation</i> — material icon named "3d rotation".
static const IconData threed_rotation = IconData(0xe84d, fontFamily: 'MaterialIcons');
/// <i class="material-icons md-36">4k</i> — material icon named "4k".
static const IconData four_k = IconData(0xe072, fontFamily: 'MaterialIcons');
3.怎么才能自定义字体图标
玩前端的应该都知道:还是进入阿里图标神库:iconfont
4.根据Flutter内置的类，我写了一个自动代码生成器
虽然直接也能用，不够要记住图标的unicode码，算了，还是跟Flutter看齐吧
注意：为了简单使用：拷贝到的位置，命名，请务必和下面保持一致!保持一致!
把两个文件拷贝到对应处，icon_by_toly.dart写好(在下面)，右键运行就自动生成iconfont.dart了
代码生成器：icon_by_toly.dart
import 'dart:io';
main() {
var result = """import 'package:flutter/widgets.dart';
//Power By 张风捷特烈--- Generated file. Do not edit.
class TolyIcon {
TolyIcon._();
""";
var fileCss = File.fromUri(Uri.parse("${Uri.base}iconfont/iconfont.css"));
if (!fileCss.existsSync()) {
return;
}
var read = fileCss.readAsStringSync();
var split = read.split(".icon-");
split.forEach((str) {
if (str.contains("before")) {
var split = str.split(":");
result += "static const IconData " +
split[0].replaceAll("-", "_") +
" = const IconData(" +
split[2].replaceAll("\"\\", "0x").split("\"")[0] +
", fontFamily: \"TolyIcon\");\n";
}
});
result+="}";
fileCss.delete();
var fileOut = File.fromUri(Uri.parse("${Uri.base}lib/iconfont.dart"));
fileOut.writeAsStringSync(result);
var config="""
fonts:
- family: TolyIcon
fonts:
- asset: iconfont/iconfont.ttf
""";
var yaml = File.fromUri(Uri.parse("${Uri.base}pubspec.yaml"));
if (yaml.readAsStringSync().contains("TolyIcon")) {
return;
}
yaml.writeAsString(config,mode: FileMode.append);
}
pubspec.yaml的flutter标签下也会自动生成配置：
fonts:
- family: TolyIcon
fonts:
- asset: iconfont/iconfont.ttf
Icon(TolyIcon.icon_spring_boot)//颜色可自行处理
友情提示：下载之前最好把图标名字改一下，不然之后找起来费劲
如果实在不想该，可以点击这里查看名字和图标的对应情况
二、综合小案例
1.初始代码：主页面：android_stack.dart
import 'package:flutter/material.dart';
class AndroidPage extends StatefulWidget {
@override
_AndroidPageState createState() => _AndroidPageState();
}
class _AndroidPageState extends State<AndroidPage>
with SingleTickerProviderStateMixin {
@override
void initState() {
super.initState();
}
@override
Widget build(BuildContext context) {
var scaffold = Scaffold(
appBar: AppBar(
title: Text("张风捷特烈"),
),
body: Container(),
floatingActionButton: FloatingActionButton(
onPressed: () {
},
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
return scaffold;
}
}
2.拼接底部条
2.1:常量的准备：(为了方便使用或修改)
class ItemBean {
Color color;
IconData iconId;
String info;
ItemBean(this.color, this.iconId, this.info);
}
//底部栏图标信息
var iconLi=[
ItemBean(Color(0xff8FC552),TolyIcon.android,"Android"),
ItemBean(Color(0xff6BFB00),TolyIcon.icon_spring_boot,"SpringBoot"),
ItemBean(Color(0xff63DAFF),TolyIcon.react,"React"),
ItemBean(Color(0xffF3D861),TolyIcon.biji,"编程随笔"),
ItemBean(Color(0xff5CEBF2),TolyIcon.daima,"系列文章")
];
2.2:底部栏：
//成员变量
int _curIndex = 0;
//底部栏
var bottomNavigationBar = BottomNavigationBar(
items: iconLi.map((item) {
return BottomNavigationBarItem(
title: Text(
item.info,
style: TextStyle(fontSize: 12, color: Colors.black),
),
icon: Icon(
item.iconId,
color: item.color,
),
backgroundColor: Color(0xffffffff));
}).toList(),
currentIndex: _curIndex,
onTap: _onTapBNB,
);
2.3：底部栏点击监听：_onTapBNB
//底部栏点击监听
void _onTapBNB(int position) {
_curIndex = position;
setState(() {});
}
3:页面条目：
第五天写了几个条目，现在拿来用(详细分析见第五天，这里不废话了)
| 静态填充 | 左侧滑栏 |
|---|---|
3.1：左侧滑栏:left_draw.dart
class LeftDrawPage extends StatefulWidget {
@override
_LeftDrawPageState createState() => _LeftDrawPageState();
}
class _LeftDrawPageState extends State<LeftDrawPage>
with SingleTickerProviderStateMixin {
@override
Widget build(BuildContext context) {
//左边头像
var headImg3 = Image.asset(
"images/icon_90.png",
width: 50,
height: 50,
);
//中间的信息
var center3 = Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
"张风捷特烈",
style: bigStyle,
),
Row(
children: <Widget>[
Icon(Icons.next_week, size: 15),
pd(Text("创世神 | 无"), l: 5)
],
),
Row(
children: <Widget>[
Icon(Icons.keyboard, size: 15),
pd(Text("海的彼岸有我未曾见证的风采"), l: 5)
],
),
],
);
var rowLine3 = Row(
children: <Widget>[
pda(headImg3, 5),
Expanded(child: pda(center3, 5)),
],
);
var test3 = Card(
child: Container(
height: 95,
color: Colors.white,
padding: EdgeInsets.all(5),
child: rowLine3));
return Drawer(
elevation: 5,
child: Container(
padding: EdgeInsets.only(top: 50),
alignment: AlignmentDirectional.topCenter,
color: Color(0xff99C6F9),
child: test3));
}
}
3.2：列表静态填充:home_list.dart
class HomeListPage extends StatefulWidget {
@override
_HomeListPageState createState() => _HomeListPageState();
}
class _HomeListPageState extends State<HomeListPage> {
@override
Widget build(BuildContext context) {
return ListView.builder(
itemCount: 10,
itemBuilder: (BuildContext context, int index) {
return renderItem(index);
},
);
}
renderItem(int index) {
////////////////////////-----------------测试4--------------------------------
var line1_4 = Row(
children: <Widget>[
Image.asset("images/icon_90.png", width: 20, height: 20),
Expanded(
child: pd(Text("张风捷特烈"), l: 5),
),
Text(
"Flutter/Dart",
style: infoStyle,
)
],
);
var center_right = Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Text(
"Flutter第4天--基础控件(下)+Flex布局详解",
style: littelStyle,
maxLines: 2,
),
pd(
Text(
"1.2：优雅地查看：图片的适应模式--BoxFit1.3：优雅地查看：颜色混合模式--colorBlendMode",
style: infoStyle,
maxLines: 2,
overflow: TextOverflow.ellipsis,
),
t: 5),
],
);
//中间的信息
var center4 = Row(
children: <Widget>[
Expanded(child: pda(center_right, 5)),
Image.asset(
"images/wy_300x200.jpg",
width: 80,
height: 80,
fit: BoxFit.fitHeight,
)
],
);
var end4 = Row(
children: <Widget>[
Icon(
Icons.grade,
color: Colors.green,
size: 20,
),
Text(
"1000W",
style: infoStyle,
),
pd(Icon(Icons.tag_faces, color: Colors.lightBlueAccent, size: 20),
l: 15, r: 5),
Text("2000W", style: infoStyle),
],
);
var item4 = Column(
children: <Widget>[line1_4, Expanded(child: center4), end4],
);
var aCard = Card(
child: Container(
height: 160,
color: Colors.white,
padding: EdgeInsets.all(10),
child: item4));
return aCard;
}
}
4.动态数据获取：
昨天已经把http获取数据的内容将过了，并且把服务端的数据解析了
今天就是使用这些数据，来填充静态界面，api接口介绍和NoteBean昨天已完成
封装一个获取数据的方法：简单说下用法:
style是类型：Android是A ;SpringBoot是SB ; React 是Re ; 笔记是 Note
offset和num 联合使用可以达到分页效果， 比如offset=24,num=12,就是一页12条数据的第3页
import 'dart:convert';
import 'package:http/http.dart' as client;
import 'package:toly/pager/day7/bean.dart';
const BASE_URL = 'http://192.168.43.60:8089';//api接口的域名自己改一下
const API = '/api/android/note/';
Future<List<NoteBean>> get({style = '', offset = 0, num = 1}) async {
var dataLi = <NoteBean>[];
var url = BASE_URL + API + style + "/" + "$offset" + "/" + "$num";
try {
final response = await client.get(url);
if (response.statusCode == 200) {
var result = ResultBean.fromJson(json.decode(response.body));
List data = result.data;
print(NoteBean.fromJson(data[0]).type);
for (int i = 0; i < data.length; i++) {
dataLi.add(NoteBean.fromJson(data[i]));
}
return dataLi;
}
} catch (e) {
print(e);
}
}
5.用一个数据来进行填充测试：
主页面：android_stack.dart,initState的时候获取数据，并更新状态
//定义一个成员变量
List<NoteBean> _notes = [];
@override
void initState() {
super.initState();
get(num: 1).then((beanLi) {
_notes = beanLi;
setState(() {});
});
}
列表界面：home_list.dart:接收主界面传来的_notes，并渲染数据
class HomeListPage extends StatefulWidget {
List<NoteBean> _notes;
HomeListPage(List<NoteBean> notes) {
_notes = notes;
}
@override
_HomeListPageState createState() => _HomeListPageState();
}
class _HomeListPageState extends State<HomeListPage> {
@override
Widget build(BuildContext context) {
var notes = widget._notes;
return ListView.builder(
itemCount: notes.length,
itemBuilder: (BuildContext context, int index) {
return renderItem(notes[index]);
},
);
}
//渲染条目
renderItem(NoteBean note) {
var line1_4 = Row(
children: <Widget>[
Image.asset("images/icon_90.png", width: 20, height: 20),
Expanded( child: pd(Text("张风捷特烈"), l: 5),),
Text( note.type,style: infoStyle,)
],
);
var center_right = Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[Text(note.name,style: littelStyle,maxLines: 2,),
pd(Text( note.info, style: infoStyle, maxLines: 2,
overflow: TextOverflow.ellipsis, ), t: 5),
],
);
//中间的信息
var center4 = Row(
children: <Widget>[
Expanded(child: pda(center_right, 5)),
Image.network( note.imgUrl,
width: 80, height: 80, fit: BoxFit.fitHeight )
],
);
var end4 = Row(
children: <Widget>[
Icon( Icons.grade, color: Colors.green, size: 20, ),
Text( "1000W", style: infoStyle,),
pd(Icon(Icons.tag_faces, color: Colors.lightBlueAccent, size: 20),
l: 15, r: 5),
Text("2000W", style: infoStyle),
],
);
var item4 = Column(
children: <Widget>[line1_4, Expanded(child: center4), end4],
);
var aCard = Card(
child: Container( height: 160,color: Colors.white,
padding: EdgeInsets.all(10), child: item4));
return aCard;
}
}
现在万事俱备，东风也到了,num小小动一下：num=30
| -- | -- |
|---|---|
也许你感觉还未开始，但确实已经结束了...
6.底部导航栏的切换：(下面两个图一样的，为了撑场面...)
刚才是数据没有分类型，现在点击底部导航，按范围进行展示
get(style: "area/A", num: 30)//这样就是展示又有安卓类的文章
| - | - |
|---|---|
android_stack.dart添加成员变量
这里我默认加载完，做分页的话，再添加个_count的成员变量就行了
String style = "area/A";
//页面打开，默认加载安卓页
@override
void initState() {
super.initState();
get(style: style, num: 1000).then((beanLi) {
_notes = beanLi;
setState(() {});
});
}
//底部栏点击监听---动态改变范围
void _onTapBNB(int position) {
switch (position) {
case 0:
style = "area/A";
break;
case 1:
style = "area/SB";
break;
case 2:
style = "area/Re";
break;
case 3:
style = "area/Note";
break;
case 4:
style = "area/A";
break;
}
_curIndex = position;
get(style: style, num: 1000).then((beanLi) {
_notes = beanLi;
setState(() {});
});
}
7.底部栏和搜索功能
底部栏用法详情在第四篇
| -- | -- |
|---|---|
底部栏:这里把事件写在里面了，你也可以抽成方法
或者有些控件太长，你也可以抽出来做变量
var searchSheet = BottomSheet(
onClosing: () {},
builder: (context) => (Card(
color: Color.fromARGB(255, 214, 242, 251),
child: Wrap(
children: <Widget>[
Center(child: pdhv(TextField(
onChanged: (v) {style = "name/" + v;}), h: 60)),
Center(child: pdhv( GestureDetector(child:
Image.asset("images/icon_90.png",width: 50,height: 50 ),
onTap: () {
get(style: style, num: 1000).then((beanLi) {
_notes = beanLi;
setState(() {});
});
},
),
v: 10)),
],
))));
//点击按钮弹出：
var scContext; //先声明一下Scaffold的context
var scaffold = Scaffold(
appBar: AppBar(
title: Text("张风捷特烈"),
),
body: Builder(builder: (context) {
scContext = context;
return HomeListPage(_notes);
}),
floatingActionButton: FloatingActionButton(
onPressed: () {
Scaffold.of(scContext).showBottomSheet(searchSheet.builder);
},
//下面不用修改，略...
Ok,小案例就这样
三、Android代码交互
1.最简单的无参无返回函数调用：两对应
不得不说：前六天不能弹吐司真是不好受，原生交互肯定先拿他开刀
1.1：Android代码
public class MainActivity extends FlutterActivity {
private static final String CHANNEL = "www.toly1994.com/test.名字随意起";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
GeneratedPluginRegistrant.registerWith(this);
new MethodChannel(getFlutterView(), CHANNEL).setMethodCallHandler(
new MethodChannel.MethodCallHandler() {
@Override
public void onMethodCall(MethodCall methodCall, MethodChannel.Result result) {
if (methodCall.method.equals("showToast")) {
showToast("Hello Flutter,I am in Android");
} else {
result.notImplemented();
}
}
}
);
}
/**
* 显示吐司
*
* @param msg 信息
*/
public void showToast(String msg) {
Toast toast = Toast.makeText(this, msg, Toast.LENGTH_SHORT);
toast.show();
}
}
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
const platform = const MethodChannel("www.toly1994.com/test.名字随意起");
var toastTest = Center(
child: RaisedButton(
onPressed: () {
platform.invokeMethod("showToast");
},
child: new Text("点击弹吐司"),
),
);
2.Flutter中传参，调用Android含参方法:三对应
2.1：Android代码
public class MainActivity extends FlutterActivity {
private static final String CHANNEL = "www.toly1994.com/test.名字随意起";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
GeneratedPluginRegistrant.registerWith(this);
new MethodChannel(getFlutterView(), CHANNEL).setMethodCallHandler(
new MethodChannel.MethodCallHandler() {
@Override
public void onMethodCall(MethodCall methodCall, MethodChannel.Result result) {
if (methodCall.method.equals("showToast")) {
//解析参数
String msg = methodCall.argument("msg");
showToast(msg);
} else {
result.notImplemented();
}
}
}
);
}
/**
* 显示吐司
*
* @param msg 信息
*/
public void showToast(String msg) {
Toast toast = Toast.makeText(this, msg, Toast.LENGTH_SHORT);
toast.show();
}
}
2.2:Flutter代码：
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
const platform = const MethodChannel("www.toly1994.com/test.名字随意起");
var toastTest = Center(
child: RaisedButton(
onPressed: () {
platform.invokeMethod("showToast",{"msg":"Flutter大爷我赏你一口吐司"});
},
child: new Text("点击弹吐司"),
),
);
2.3：加返回值的方法调用：
举什么例子，我想了一会，就来个MD5码吧
//Activity添加判断分支
if (methodCall.method.equals("getMD5")) {
String arg = methodCall.argument("arg");
String md5 = getMD5(arg);
result.success(md5);
}
/**
* 获取一个字符串的Md5值
*
* @param content 内容
* @return Md5值
*/
public String getMD5(String content) {
content = content + "芝麻开门";
try {
MessageDigest digest = MessageDigest.getInstance("MD5");
digest.update(content.getBytes());
return getHashString(digest);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return null;
}
private static String getHashString(MessageDigest digest) {
StringBuilder builder = new StringBuilder();
for (byte b : digest.digest()) {
builder.append(Integer.toHexString((b >> 4) & 0xf));
builder.append(Integer.toHexString(b & 0xf));
}
return builder.toString();
}
2.2:Flutter代码：
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
const platform = const MethodChannel("www.toly1994.com/test.名字随意起");
var toastTest = Center(
child: RaisedButton(
onPressed: () {
var result= platform.invokeMethod("getMD5",{"arg":"https://www.jianshu.com/p/9bac0072d1a0"});
result.then((str){
platform.invokeMethod("showToast",{"msg":str});
});
},
child: new Text("点击弹吐司"),
),
);
基本上也就这三种情况
[彩蛋]--以前Mark的一个小点：Card的shape
有人说学习的时候一个问题会牵扯到很多其他的问题，问题一多就无从下手
我只说一个字："栈"：来最后一波学习看源码的方法了,走起
1.shape是什么:形状
现在的问题栈
可见默认圆角是4的RoundedRectangleBorder
---->[shape属性]----
/// The default shape is a [RoundedRectangleBorder] with a circular corner
/// radius of 4.0.
final ShapeBorder shape;
---->[RoundedRectangleBorder]----
const RoundedRectangleBorder({
this.side = BorderSide.none,
this.borderRadius = BorderRadius.zero,
//可见有两个属性：BorderSide和BorderRadius
---->[BorderSide]----
class BorderSide {
/// Creates the side of a border.
///
/// By default, the border is 1.0 logical pixels wide and solid black.
const BorderSide({
this.color = const Color(0xFF000000),
this.width = 1.0,
this.style = BorderStyle.solid,
---->[BorderRadius]----
class BorderRadius extends BorderRadiusGeometry {
/// Creates a border radius where all radii are [radius].
const BorderRadius.all(Radius radius) : this.only(
topLeft: radius,
topRight: radius,
bottomLeft: radius,
bottomRight: radius,
);
/// Creates a border radius where all radii are [Radius.circular(radius)].
BorderRadius.circular(double radius) : this.all(
Radius.circular(radius),
);
---->[Radius]------
class Radius {
/// Constructs a circular radius. [x] and [y] will have the same radius value.
const Radius.circular(double radius) : this.elliptical(radius, radius);
/// Constructs an elliptical radius with the given radii.
const Radius.elliptical(this.x, this.y);
/// The radius value on the horizontal axis.
final double x;
/// The radius value on the vertical axis.
final double y;
一个shape牵扯出这么多类，有人可能就
栈溢出了，还是使用默认的吧，等一下，且听我分析
当Radius入问题栈之后，看一下也就是两个值，就出栈了，BorderRadius跟着也出栈了
BorderSide三个字段，看一下，出栈了，现在栈顶是RoundedRectangleBorder你还不会吗?
2. RoundedRectangleBorder改变圆角大小+边线
var card_shape = Card(
// shape: CircleBorder(side: BorderSide(width: 1)),
shape: RoundedRectangleBorder(
side:BorderSide(color: Color(0xffD516F5),width: 5) ,
borderRadius: BorderRadius.all(Radius.circular(20))),
clipBehavior: Clip.antiAlias,
child: Container(
width: 100,
height: 100,
color: Color(0xffCDECF6),
child: Center(child:Text(
"捷",
style: TextStyle(color: Colors.black,fontSize: 40),
) ,),
));
那弹栈过后问题跑哪里?
我想应该是临时知识库吧,你解决的问题中获取的知识，经验会累积
可能长久不用知识库里的知识会漏掉，但印象有的，下一次再入栈，解决起来会更快
在的知识库里扎根的知识，那当你遇到时，就不是问题，直接弹栈，这样想学习是不是也挺好玩的
大神级的Coder知识库丰富，问题都不是问题，也许偶尔入栈一两个，但栈很深(感觉挺浪费哈)
新手就是栈比较浅，问题多，所以容易StackOver,所以修炼你容忍问题的能力(栈深)很有必要
像我这样不深不浅的刚刚好，会碰到问题，也能一点点解决，一点一点踏上封神之路
但所有的大神也都是从新手这样过来的，解决问题的能力也不是与生俱来，祝你慢慢弹栈，收获多多。
3.接下来看ShapeBorder在栈顶，我们去瞅瞅
BorderSide现在已经化敌为友，CircleBorder岂不是秒出栈，并且俘获
CircleBorder一枚
而且BorderSide强化+1，知识就是这样积累的，难道还有别的方法吗?除非记忆拷贝...
转一转当CD背景感觉挺不错
var card_shape = Card(
shape: CircleBorder(side: BorderSide(width: 15,color: Color(0xffF9DFA7))),
clipBehavior: Clip.antiAlias,
child: Container(
width: 100,
height: 100,
color: Color(0xffCDECF6),
child: Center(child:Text(
"捷",
style: TextStyle(color: Colors.black,fontSize: 40),
) ,),
));
4.前方高能，非战斗人员带好零食
其实觉得shape好玩，是在粗略看源码时,看到了canvas,才mark的
自定义ShapeBorder走起：画具在手，天下我有
var card_shape = Card(
shape: StarBorder(),
// shape: CircleBorder(side: BorderSide(width: 15,color: Color(0xffF9DFA7))),
// shape: RoundedRectangleBorder(
// side:BorderSide(color: Color(0xffD516F5),width: 5) ,
// borderRadius: BorderRadius.all(Radius.circular(20))),
clipBehavior: Clip.hardEdge,
child: Container(
width: 100,
height: 100,
color: Color(0xffCDECF6),
child: Center(
child: Text(
"捷",
style: TextStyle(color: Colors.black, fontSize: 40),
),
),
));
class StarBorder extends ShapeBorder {
@override
// TODO: implement dimensions
EdgeInsetsGeometry get dimensions => null;
@override
Path getInnerPath(Rect rect, {TextDirection textDirection}) {
// TODO: implement getInnerPath
return null;
}
@override
Path getOuterPath(Rect rect, {TextDirection textDirection}) {
print(rect.right);
return regularPolygonPath(10, 50,x: rect.height/2,y: rect.width/2);
}
@override
void paint(Canvas canvas, Rect rect, {TextDirection textDirection}) {
canvas.translate(50, 50);
// canvas.drawPath(nStarPath(5, 40, 20), new Paint());
}
@override
ShapeBorder scale(double t) {
// TODO: implement scale
return null;
}
}
路径封装(稍微优化了一下)
/**
* n角星路径
*
* @param num 几角星
* @param R 外接圆半径
* @param r 内接圆半径
* @return n角星路径
*/
Path nStarPath(int num, double R, double r, {x = 0, y = 0}) {
Path path = new Path();
double perDeg = 360 / num; //尖角的度数
double degA = perDeg / 2 / 2;
double degB = 360 / (num - 1) / 2 - degA / 2 + degA;
path.moveTo(cos(_rad(degA)) * R+x, (-sin(_rad(degA)) * R+y));
for (int i = 0; i < num; i++) {
path.lineTo(
cos(_rad(degA + perDeg * i)) * R+x, -sin(_rad(degA + perDeg * i)) * R+y);
path.lineTo(
cos(_rad(degB + perDeg * i)) * r+x, -sin(_rad(degB + perDeg * i)) * r+y);
}
path.close();
return path;
}
/**
* 画正n角星的路径:
*
* @param num 角数
* @param R 外接圆半径
* @return 画正n角星的路径
*/
Path regularStarPath(int num, double R,{x = 0, y = 0}) {
double degA, degB;
if (num % 2 == 1) {
//奇数和偶数角区别对待
degA = 360 / num / 2 / 2;
degB = 180 - degA - 360 / num / 2;
} else {
degA = 360 / num / 2;
degB = 180 - degA - 360 / num / 2;
}
double r = R * sin(_rad(degA)) / sin(_rad(degB));
return nStarPath(num, R, r,x: x,y:y);
}
/**
* 画正n边形的路径
*
* @param num 边数
* @param R 外接圆半径
* @return 画正n边形的路径
*/
Path regularPolygonPath(int num, double R,{x = 0, y = 0}) {
double r = R * cos(_rad(360 / num / 2)); //!!一点解决
return nStarPath(num, R, r,x: x,y:y);
}
/**
* 角度制化为弧度制
*
* @param deg 角度
* @return 弧度
*/
double _rad(double deg) {
return deg * pi / 180;
}
师傅领进门，修行在个人，我已经把功力传给你了,能否修成正果，就看各自造化。
事了拂衣去，深藏功与名,Ok,Flutter七日游，完捷散花，自认为没有烂尾，耶!
后记：捷文规范
1.本文成长记录及勘误表
| 项目源码 | 日期 | 备注 |
|---|---|---|
| V0.1-github | 2018-12-22 | Flutter第7天--字体图标+综合小案例+Android代码交互 |
2.更多关于我
| 笔名 | 微信 | 爱好 | |
|---|---|---|---|
| 张风捷特烈 | 1981462002 | zdl1994328 | 语言 |
| 我的github | 我的简书 | 我的掘金 | 个人网站 |
3.声明
1----本文由张风捷特烈原创,转载请注明
2----欢迎广大编程爱好者共同交流
3----个人能力有限，如有不正之处欢迎大家批评指证，必定虚心改正
4----看到这里，我在此感谢你的喜欢与支持
