Angular:如何从不同模块中的另一个组件调用组件方法

我试图从B_Module拥有的B_Component中调用A_Module拥有的A_Component的方法，并在将A_Component作为参数添加到B_Component构造函数中时得到以下错误:

I am trying to call a method of A_Component owned by A_Module from B_Component owned by B_Module and am getting the following error as soon as I add A_Component as a parameter to the B_Component constructor:

NullInjectorError:没有A_Component的提供者！

NullInjectorError: No provider for A_Component!

这两个组件不是父/子.它们的模块由app.module导入

The two components are not parent/child. Their modules are imported by app.module

(为简洁起见，代码摘要)

(Code summarized for brevity)

A_Module:

import { A_Component } from '...'

@NgModule({
    imports: [...],
    declarations: [A_Component],
    exports: [A_Component],
})

export class A_Module { }

B_Module:

import { A_Module } from '...'
import { B_Component } from '...'

@NgModule({
    imports: [A_Module],
    declarations: [B_Component]
})

export class B_Module { }

A_Component:

A_Component:

export class A_Component {
    someMethod() {...}
}

B_Component:

B_Component:

import { A_Component } from '...'

export class B_Component {

    constructor(public a_Component: A_Component)) {} //this param causes error

    callSomeMethod() {
        this.a_Component.someMethod();
    }
}

这不是如何在模块之间调用组件方法吗?唯一的方法就是通过服务吗?

Is this not how to call component methods across modules? Is the only way to do this is with a service?