好用的TypeScript

TS中的枚举定字符串

• 通过给枚举定义字符串可以使用消息管理器
• 之前都是用静态对象定义

import { EventEmitter } from 'events';

enum EventType {
    OPEN = 'open',
    CLOSE = 'close',
}

const eventEmitter = new EventEmitter();

eventEmitter.on(EventType.OPEN, () => {
    console.log('call open');
});

eventEmitter.on(EventType.CLOSE, () => {
    console.log('call close');
});

eventEmitter.emit(EventType.OPEN);
eventEmitter.emit(EventType.CLOSE);

TS中的单例模式

export class Singleton {
    private static _instance: Singleton
    private constructor() {}
    static getInstance() : Singleton {
        if (!Singleton._instance) {
            Singleton._instance = new Singleton()
        }
        return Singleton._instance
    }
}

TS中的可继承单例

• 使用函数方法

export function Singleton<T>() {
    class SingletonTemp {
        private static _instance: any;
        protected constructor() {}
        static getInstance() : T {
            if (!SingletonTemp._instance) {
                SingletonTemp._instance = new this();
            }
            return SingletonTemp._instance as T;
        }
    }
    return SingletonTemp;
} 

• 使用继承

class Test extends Singleton<Test>() {
    print(msg: string) {
        console.log(msg);
    }
}

• 测试

Test.getInstance().print("single")

使用type定义一个简单的pair

type pair<K, V> = [K, V];
const p: pair<number, string> = [1, 'name'];

TS中的Setter和getter实现

private _name: string

set name(val: string) {
    this._name = val
}

get name() {
    return this._name
}

TS函数模拟传入对象指针

• 使用对象解构完成对象指针传入
• 将当前对象的引用在函数做修改

let data = {
    id: 1
}

function changeData({data: any} : any) {
    let d = {
        id: 2
    }
    data = d;
}
console.log('data before', data);
changeData({data});
console.log('data after',data);

• 输出内容

data before { id: 1 }
data after { id: 2 }