动态import

动态import在业务上除了能实现条件延迟加载，还可以实现部分反射功能。实例如下，HAP动态import HAR包harlibrary，并调用静态成员函数staticAdd()、成员函数instanceAdd()，以及全局方法addHarlibrary()。

// harlibrary's src/main/ets/utils/Calc.ets
export class Calc {
  public static staticAdd(a:number, b:number):number {
    let c = a + b;
    console.log('DynamicImport I am harlibrary in staticAdd, %d + %d = %d', a, b, c);
    return c;
  }

  public instanceAdd(a:number, b:number):number {
    let c = a + b;
    console.log('DynamicImport I am harlibrary in instanceAdd, %d + %d = %d', a, b, c);
    return c;
  }
}

export function addHarlibrary(a:number, b:number):number {
  let c = a + b;
  console.log('DynamicImport I am harlibrary in addHarlibrary, %d + %d = %d', a, b, c);
  return c;
}

// harlibrary's Index.ets

export { Calc, addHarlibrary } from './src/main/ets/utils/Calc'

// HAP's oh-package.json5

"dependencies": {
  "harlibrary": "file:../harlibrary"
}

//HAP's src/main/ets/pages/Index.ets

import('harlibrary').then((ns:ESObject) => {
  ns.Calc.staticAdd(8, 9);  // 调用静态成员函数staticAdd()
  let calc:ESObject = new ns.Calc();  // 实例化类Calc
  calc.instanceAdd(10, 11);  // 调用成员函数instanceAdd()
  ns.addHarlibrary(6, 7);  // 调用全局方法addHarlibrary()

  // 使用类、成员函数和方法的字符串名字进行反射调用
  let className = 'Calc';
  let methodName = 'instanceAdd';
  let staticMethod = 'staticAdd';
  let functionName = 'addHarlibrary';
  ns[className][staticMethod](12, 13);  // 调用静态成员函数staticAdd()
  let calc1:ESObject = new ns[className]();  // 实例化类Calc
  calc1[methodName](14, 15);  // 调用成员函数instanceAdd()
  ns[functionName](16, 17);  // 调用全局方法addHarlibrary()
});