TypeDI @Inject()不起作用，但Container.get()起作用

Question

我面临着一个奇怪的问题，Container.get(MyServiceName)；返回所需的服务，但是用@Inject()装饰的类属性是未定义的。

我尝试过用@Service()装饰类

我确实在我的应用程序导入‘reflect-metadata’的入口点导入了反射元数据；

我想知道这是否与以下事实有关，即我不是直接从node_modules而是从依赖项中使用typedi？

应用程序既不使用Express框架，也不使用路由控制器

我的tsconfig.json：

"compilerOptions": {

    "declaration": true,
    "pretty": true,
    "esModuleInterop": true,
    "target": "esnext",
    "noImplicitAny": true,
    "noImplicitReturns": true,
    "noUnusedLocals": false,
    "moduleResolution": "node",
    "noUnusedParameters": true,
    "strictPropertyInitialization": false,
    "module": "commonjs",
    "lib": ["dom", "es2018"],
    "importHelpers": true,
    "outDir": "./dist",
    "strict": true,
    "typeRoots": ["node_modules/@types"],
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "sourceMap": true
  },
  "include": ["./src/**/*"],
  "exclude": ["node_modules", "./dist/**/*"]
}

我想要注入的服务

import MyServiceName from '../services/MyServiceName';
import { Container, Inject, Service } from 'my_dependency/lib';

export default class SomeClass{
  @Inject()
  private readonly someService: MyServiceName;

  public async someMethod(): SomeResponseType {
    const thatWorks = Container.get<MyServiceName>(MyServiceName);
    console.log(this.someService); // undefined
    console.log(thatWorks); // proper class
  }
}

我要注入的服务

@Service()
export default class MyServiceName {
  public async someMethod(): SomeReturnType {
    return someReturnedData;
  }
}

我想通过@ inject ()装饰器注入我的依赖项

Answer 1

您需要使用Container#get创建SomeClass实例，否则容器将无法注入该属性。

这对我很有效：

// a.ts
import { Service } from "typedi";
@Service()
export class Foo {
  foo() {
    return 10;
  }
}

// b.ts
import { Foo } from "./a";
import { Inject } from "typedi";

export class Bar {
  @Inject() private readonly service: Foo
  foo() {
    console.log(this.service);
  }
}

// test.ts
import "reflect-metadata";
import { Bar } from "./b";
import { Container } from "typedi";

const noFoo = new Bar();
noFoo.foo(); // yields undefined

const withFoo = Container.get<Bar>(Bar);
withFoo.foo(); // yields Foo