Angular 从 8 升级到 9，无法解析任何注射剂的所有参数

Question

我最近将 Angular 8 升级到 Angular 9，似乎没有任何东西可以依赖注入。

我在我的项目中注释掉了很多代码，基本如下所示：

// configuration.state.ts
@State<ConfigurationStateModel>({
  name: 'ConfigurationStateModel',
  defaults: defaultConfiguration,
})
export class ConfigurationState {

  constructor(
    //private configurationService: ConfigurationService,
    private configurationService: HeroService,
  ) { }

  // .. irrelevant code

}

//hero.service.ts
// generated by ng g s heroservice
import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class HeroService {

  constructor() { }
}

错误

Error: Can't resolve all parameters for ConfigurationState: (?).

at getUndecoratedInjectableFactory (core.js:17311)

at injectableDefOrInjectorDefFactory (core.js:17295)

at providerToFactory (core.js:17363)

at providerToRecord (core.js:17345)

at R3Injector.processProvider (core.js:17161)

at core.js:17122

at core.js:1400

at Array.forEach ()

at deepForEach (core.js:1400)

at R3Injector.processInjectorType (core.js:17118)

Answer 1

显然对于 NGXS，所有状态现在都必须用 @Injectable() 修饰。

这不有效：

@Injectable()
@State<ConfigurationStateModel>({
  name: 'ConfigurationStateModel',
  defaults: defaultConfiguration,
})
export class ConfigurationState {

但在 @State 之后添加它：

@State<ConfigurationStateModel>({
  name: 'ConfigurationStateModel',
  defaults: defaultConfiguration,
})
@Injectable()
export class ConfigurationState {

Angular 从 8 升级到 9，无法解析任何注射剂的所有参数

Angular upgrade from 8 to 9, Can't resolve all parameters for any injectable

dependency-injection

ngxs

angular9