typeScript之装饰器

很多语言都有装饰器，比如java和python，装饰器的目的是扩展功能使用，它的本质是一个函数，简单地装饰器

#不带参装饰器

// 装饰器
function zsq(target:any){
    // target 就是Student
    target.prototype.name = '动态扩展的属性';
    target.prototype.run = ()=>{
        console.log('动态扩展的方法');
    }
}

@zsq
class Student {
    constructor(){

    }
    dothing(){

    }
}

let stu:any = new Student();
console.log(stu.name);
stu.run()

#带参装饰器

//装饰器工厂
let zsq = (msg:string)=>{
    return (target:any)=>{
        target.prototype.name = msg
    }
}

@zsq('我是装饰器工厂')
class Student {
    constructor(){

    }
    dothing(){

    }
}
let stu = new Student();
console.log(stu.name)

#属性装饰器

function defineProperty(parames:any){
    return function(target:any,attr:any){
        target[attr] = parames
    }
}
class Student {
    @defineProperty('http://www.baidu.com')
    public url:any;
    constructor(){

    }
    dothing(){
        console.log(this.url)
    }
}
let stu = new Student();
console.log(stu.dothing())