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flutter的开发笔记

flutter's Introduction

🛠 Tech Stack

JavaScript工具：

ESLint，代码格式
Lodash.js，功能齐全并且很强大的JavaScript工具库，精简代码；
TypeScript，静态类型

Git 提交规范：

feat 增加新功能
fix 修复问题/BUG
Optimize:需要填写对应需求来源
style 代码风格相关无影响运行结果的
perf 优化/性能提升
refactor 重构
revert 撤销修改
test 测试相关
docs 文档/注释
chore 依赖更新/脚手架配置修改等
workflow 工作流改进
ci 持续集成
types 类型定义文件更改
wip 开发中

Git 生僻的命令：

git update-index --assume-unchanged 文件路径，暂时忽略文件的变更
git reset --hard 目标版本号：将版本回退
git merge targetbranch：将targetbranch合并到当前分支

Linux命令：

scp /path/to/local/file username@server:/path/to/server/directory 终端命令上传文件至服务器

flutter's People

Watchers

flutter's Issues

distributionUrl指向本地

#distributionUrl=https\://services.gradle.org/distributions/gradle-6.7-all.zip
distributionUrl=file\:///D\:/code/gradle-6.7-all.zip

flutter时间戳转化

/*  时间戳转字符串
* timestamp 时间戳
* formart ："y-m":年和月之间的符号,
* "m-d":月和日之间的符号
* "h-m":时和分之间的符号,
* "m-s":分和秒之间的符号；
* "m-a":是否显示上午和下午
*/

class Utils {
  static String dateAndTimeToString(var timestamp,
      {Map<String, String> formart}) {
    if (timestamp == null || timestamp == "") {
      return "";
    }
    String targetString = "";
    final date = new DateTime.fromMicrosecondsSinceEpoch(timestamp * 1000);
    // final String tmp = date.toString();
    String year = date.year.toString();
    String month = date.month.toString();
    if (date.month <= 9) {
      month = "0" + month;
    }
    String day = date.day.toString();
    if (date.day <= 9) {
      day = "0" + day;
    }
    String hour = date.hour.toString();
    if (date.hour <= 9) {
      hour = "0" + hour;
    }
    String minute = date.minute.toString();
    if (date.minute <= 9) {
      minute = "0" + minute;
    }
    String second = date.second.toString();
    if (date.second <= 9) {
      second = "0" + second;
    }
    // String millisecond = date.millisecond.toString();
    String morningOrafternoon = "上午";
    if (date.hour >= 12) {
      morningOrafternoon = "下午";
    }

    if (formart["y-m"] != null && formart["m-d"] != null) {
      targetString = year + formart["y-m"] + month + formart["m-d"] + day;
    } else if (formart["y-m"] == null && formart["m-d"] != null) {
      targetString = month + formart["m-d"] + day;
    } else if (formart["y-m"] != null && formart["m-d"] == null) {
      targetString = year + formart["y-m"] + month;
    }

    targetString += " ";

    if (formart["m-a"] != null) {
      targetString += morningOrafternoon + " ";
    }

    if (formart["h-m"] != null && formart["m-s"] != null) {
      targetString += hour + formart["h-m"] + minute + formart["m-s"] + second;
    } else if (formart["h-m"] == null && formart["m-s"] != null) {
      targetString += minute + formart["m-s"] + second;
    } else if (formart["h-m"] != null && formart["m-s"] == null) {
      targetString += hour + formart["h-m"] + minute;
    }

    return targetString;
  }
}

组件状态

无状态组件：静态组件，或者是说外部传入数据转化为页面展示的内容，只渲染一次；

有状态组件：是定义交互逻辑和业务数据，具有动态交互的内容界面，页面根据数据的变化多次渲染

组件生命周期

createState：在Statefulwidget中创建State的方法，当Statefulwidget执行时会立即执行createState。

initState,初始化state的各个变量，同时也可以通过服务端获取数据后调用setState()来设置state。

didChangeDependencies，在该组件的state发生改变时，【state为全局，如主题、语言等等参数】；

build：返回需要渲染的widget，因为build被执行多次，所以在build函数中只能做返回widget的逻辑；

reassemble：主要是在开发阶段使用，在debug模式下，每次热启动都会执行该方法；

didUpdateWidget：在组件重新构建，父组件发生build变化时，子组件会调用该组件，之后会再次调用本组件的build方法；

deactivate：在组件被移除节点后调用。如果没有被插到其他的节点，则调用dispose永久移除组件；

dispose：永久移除组件，释放该组件的资源

flutter生命周期源码

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter_swiper/flutter_swiper.dart';
import 'package:intl/intl.dart';

class App extends StatefulWidget {
  @override
  createState() {
    print("创建state");
    return AppState();
  }
}

class AppState extends State<App> {
  DateTime now = DateTime.now();
  int count = 90;
  String name = "测试";
  @override
  void initState() {
    print("初始化state");
    super.initState();
  }

  @override
  void didChangeDependencies() {
    print("state发生改变了");
    super.didChangeDependencies();
  }

  @override
  void didUpdateWidget(covariant App oldWidget) {
    count++;
    super.didUpdateWidget(oldWidget);
  }

  @override
  void deactivate() {
    print("deactivate");
    super.deactivate();
  }

  @override
  void dispose() {
    print("永久移除组件");
    super.dispose();
  }

  @override
  void reassemble() {
    print("reassemble");
    super.reassemble();
  }

  void changeName() {
    setState(() {
      print("设置state");
      this.name = "flutter";
    });
  }

  @override
  Widget build(BuildContext context) {
    // getCurrentTime("dhfg");
    return Scaffold(
      appBar: AppBar(
        title: Text(
          "下午好！小何",
          style: TextStyle(
            color: Colors.white,
          ),
        ),
      ),
      body: Container(
        child: Column(
          children: [
            Container(
              decoration: BoxDecoration(
                color: Colors.red,
                border: Border.all(
                  color: Colors.red,
                  width: 0.3,
                ),
              ),
              height: 200,
              child: new Swiper(
                itemBuilder: (BuildContext context, int index) {
                  return new Image.network(
                    "https://tse3-mm.cn.bing.net/th/id/OIP.llTGkZjpc-7YxclmweQw-QHaFF?pid=Api&rs=1",
                    fit: BoxFit.fitWidth,
                  );
                },
                itemCount: 3,
                // pagination: new SwiperPagination(),
                autoplay: true,
                // control: new SwiperControl(),
              ),
            ),
            Container(
              padding: EdgeInsets.all(40),
              decoration: BoxDecoration(
                border: Border.all(
                  color: Colors.red,
                  width: 0.2,
                ),
                // borderRadius: BorderRadius.only(topLeft: 12, topRight: 12),
              ),
              child: FlatButton(
                child: Text("$name   $count"),
                onPressed: () => {
                  this.changeName(),
                },
              ),
            ),
            Container(
              child: Sub(),
            ),
          ],
        ),
      ),
    );
  }
}

class Sub extends StatefulWidget {
  @override
  createState() {
    return SubState();
  }
}

class SubState extends State<Sub> {
  String name = "新测试";
  String currentTieStr;

  @override
  void initState() {
    print("sub  init  state");
    super.initState();
    this.currentTieStr = this.getcurrentTime();
    refreshTimeStr();
  }

  String getcurrentTime() {
    DateTime now = DateTime.now();
    var nowTime = DateFormat("yy-MM-dd  hh:mm:ss");
    return nowTime.format(now);
  }

  void refreshTimeStr() {
    const period = Duration(milliseconds: 900);
    Timer.periodic(period, (timer) {
      setState(() {
        this.currentTieStr = getcurrentTime();
      });
    });
  }

  @override
  void didChangeDependencies() {
    print("sub did change dependencies");
    super.didChangeDependencies();
  }

  @override
  void didUpdateWidget(covariant Sub oldWidget) {
    print("sub did update widget");
    super.didUpdateWidget(oldWidget);
  }

  @override
  void deactivate() {
    print("sub dispose");
    super.deactivate();
  }

  @override
  void reassemble() {
    print("sub  reassemble");
    super.reassemble();
  }

  @override
  Widget build(BuildContext context) {
    print(this.currentTieStr);
    return Text(this.currentTieStr);
  }
}

duxinyues / flutter Goto Github PK

flutter's Introduction

🛠 Tech Stack

JavaScript工具：

Git 提交规范：

Git 生僻的命令：

Linux命令：

flutter's People

Watchers

flutter's Issues

distributionUrl指向本地

flutter时间戳转化

组件状态

组件生命周期

flutter生命周期源码

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