学习鸿蒙基础（1）

一夜之间鸿蒙崛起了。大家都在学鸿蒙。并且就业岗位的工资那是杠杠的呀。去年一年没有写博客了。去年夫人给生了个宝宝。忙着照顾夫人和宝宝了。太忙了。根本没有时间写博客。今年要坚持学习。为了给孩子赚奶粉钱。努力学习新知识。学习鸿蒙。希望鸿蒙赶紧出基于pc的操作系统。这样就可以一统天下了。

鸿蒙的语言采用 ArkTs，ArkTs继承了TypeScript。TypeScript 是一种基于 JavaScript 构建的强类型编程语言。并且在前年我学习cocos的时候。就是用ts写的小游戏。小游戏是写的差不多了。奈何腾讯云开发收费了。我的小游戏暂且搁浅了。但是和ts咱们还是相知相识的。先简单的复习一下。

ts语法基础回顾

// 字符串
let my1: string = "中国" //块级作用域
var my2: string = "我" //全局作用域
const my3: string = "世界" //常量不能赋值了

//布尔类型
let bool1: boolean = true

//数字类型
let num: number = 900

// 数组
let list: Array = ["ni", "wo", "ta"]
let datalist: string[] = ["中国", "地球", "世界"]

//联合类型
let uni1: string | number | boolean = 100
let
uni2:Array < string | number | boolean >= [1, 3, true, "nihao"]
let uni3: (string | number)[] = ["woaizhonguo", 9999]

// 任意类型
let every: any = "forever"

//枚举
enum zimu {
  "C", "D", "E"
}

enum zimu2 {
  "c" = 1,
  "d" = 2,
  "e" = 3
}

//对象  ?:表示可选的
let school: {
  name: string,
  location?: string,
  age: number,
  isNiuBi: boolean
} = {
  name: "清华大学", location: "北京", age: 100, isNiuBi: true
}

//接口
interface car{
  name:string ,
  age:number,
  type:string,
  location?:string ,//可选
  [other:string ]:any//任意类型，可以扩展属性
}

let jili:car={
  name:"帝豪",
  age:10,
  type:"电动"
}
jili.location="天津"
jili.speed="1000km/h"

//判断语句
let name="harmonyos"
if (name==="鸿蒙"){//=== 既判断类型又判断值
  console.log("hi")
}else if(name=="harmonyos"){
  console.log("yes")
}

// for 循环
let datalist1: string[] = ["中国", "地球", "世界"]
for (let i of datalist1) {//for 拿到的是内容
  console.log(i)
}

for(let i in datalist1){//in 拿到的是角标索引
  console.log(datalist1[i])
}

//普通函数
function say(){
  console.log("hello harmonyos")
}
say()

//箭头函数
const text = () => {
  console.log("hello 箭头函数")
}
text()

//带限定的箭头函数
const test = (type: number): string => {
  var text = "你好 鸿蒙"
  switch (type) {
    case 1:
      text = "鸿蒙爸爸"
      break;
    case 2:
      text = "鸿蒙爷爷"
      break
    default:
      text = "鸿蒙先人"
      break
  }
  return text;
}
console.log(test(3))

//class类
class Area {
  public id: string;
  protected x: number;
  private y: number;
  public width: number;
  public height: number;

  constructor(id: string, x: number, y: number, width: number, height: number) {
    this.id = id
    this.x = x
    this.y = y
    this.width = width
    this.height = height
  }

  drawLocation(): number {
    return (this.x) * (this.y)
  }
}

let a = new Area("tv", 0, 0, 1080, 1920)
console.log(a.x)

class littleArea extends Area {
  public angle: number
  constructor(id: string, x: number, y: number, width: number, height: number, angle: number) {
    this.id = id
    this.x = x
    this.y = y
    this.width = width
    this.height = height
    this.angle=angle
  }
  drawLocation(): number {
    return (this.x) * (this.y)*(this.angle)
  }
}
let little=new littleArea("phone",0,0,540,960,60)
console.log(little.x)



//接口
interface Study {
  tiantian()
}
class yuwen implements Study {
  tiantian() {
    console.log("我爱学语文")
  }
}

class shuxue implements Study {
  tiantian() {
    console.log("我爱学数学")
  }
}

function init(xs: Study) {
  xs.tiantian()
}

init(new yuwen())
init(new shuxue())

//泛型类
class Cache {
  private map = {}

  setCache(key: string, value: T) {
    this.map[key] = value
  }

  getCache(key: string) {
    return this.map[key]
  }
}
let obj=new Cache()

obj.setCache("nihao ","我爱祖国")
obj.getCache("nihao ")

导出utils对象和方法

const school={
  student:"留白的云",
  teacher:"孔子",
  time:111
}

function read(){
  console.log("知之为知之，不知为不知是知也")
}

// 导出这个对象
export default  school
// 导出这个方法
export {read}

 导出到华为的ets中，和js\微信小程序的导出一样一样的。

import '../ts/hello.ts'
import School  from '../ts/utils'
console.log(School.student)
import { read as Read}  from '../ts/utils'
Read()

@Entry
@Component
struct Index {
  @State message: string = 'Hello Harmonyos'

  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontSize(40)
          .fontWeight(FontWeight.Bold)
      }
      .width('100%')
      .height('50%')
    }
    .height('100%')
    .width('90%')
  }
}