如何通過DI

Question

注入現有模型的層次結構類，具有角2個服務有了這樣一個模型層次：

export class A { 
    constructor() { 
     // Here service X is needed for some own functions 
    } 
} 

export class B extends A { 
    constructor() { 
     // Here service Y is needed for some own functions 
     super(...) 
    } 
} 

export class C extends B { 
    constructor(parent, data) { 
     super(...) 
    } 
} 

我想實例C對象。所以問題是：

我該如何注入X和Y服務？

• 我應該把所有的人都在C構造函數，並傳遞給基類與super？
• 它們可以與已有的參數parent和data混合嗎？
• 有一些方法我可以只在B級別注入Y級別，X級別在A級別？所以不知何故，我避免在super上傳遞這些參考？

Answer 1

export class A { 
    constructor(serviceX: ServiceX) { 
    // Here service X is needed for some own functions 
    this.serviceX = serviceX; 
    } 
} 

export class B extends A { 
    constructor(serviceX: ServiceX, private _serviceY: ServiceY) { 
    // Here service Y is needed for some own functions 
    super(serviceX); 
    this.servicxY = serviceY; 
    } 
} 

export class C extends B { 
    constructor(serviceX: ServiceX, serviceY: ServiceY) { 
    super(_serviceX, serviceY); 
    } 
} 

又見Angular2 access global service without including it in every constructor