角度 DI:将值令牌注入工厂提供程序

Question

是否可以将InjectionToken注入工厂提供程序：

目前，我已经编写了代码：

export const HOST_TOKEN = new InjectionToken<string>("host");
let configDataServiceFactory = (userService: UserService, host: string) => {
return new Config("host", 8080, userService.getUser(), userService.getPasswd());
};
export let configDataServiceProvider =
{
provide: CONFIG_API,
useFactory: configDataServiceFactory,
deps: [UserService, HOST_TOKEN]
};

进入我的模块：

@NgModule(
providers: [
{provide: HOST_TOKEN, useValue: "allianz-host"},
configDataServiceProvider
]
)

然而，角度是在configDataServiceProvider值"host"上注入的，而不是"host-allianz"

有什么想法吗？

Answer 1

是的，您可以使用如下所示@Inject装饰器来执行此操作，这将帮助您从 DI 容器中提取相关依赖项。

let configDataServiceFactory = (userService: UserService, @Inject(HOST_TOKEN) host: string) => {
return new Config(host, 8080, userService.getUser(), userService.getPasswd());
};

---

您也可以考虑以下选项。基本上所有注册InjectionToken都可以从应用程序Injector中检索，这可以通过在实例上调用get方法并传递InjectorToken名称来实现injector。

export const HOST_TOKEN = new InjectionToken<string>("host");
let configDataServiceFactory = (userService: UserService, injector: Injector) => {
let host = injector.get(HOST_TOKEN); //retrieved token from injector
return new Config(host, 8080, userService.getUser(), userService.getPasswd());
};
export let configDataServiceProvider =
{
provide: CONFIG_API,
useFactory: configDataServiceFactory,
deps: [UserService, Injector]
};

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