Angular-无法解析组件ng build --prod的所有参数

时间:2018-07-11 01:10:42

标签: angular ng-build

我试图构建我的角度应用程序,但由于此错误而失败

 ERROR in : Can't resolve all parameters for SimpleLookupAddEditFormComponent 
 in C:/Users/lastr/Source/Repos/SMATA/Code/ng/smata-ng/src/app/system- 
 list/simple-lookup-add-edit/simple-lookup-add-edit.component.ts: (?, [object 
 Object], [object Object], [object Object]).

这是组件的代码。这是基本组成部分。这里缺少什么吗?也许构造函数属性有问题?

 import { Component, OnInit } from '@angular/core';
 import { SimpleLookupBaseService } from '../services/simple-lookup-base/simple-lookup-base.service';
 import { ActivatedRoute, Router } from '@angular/router';
 import validationEngine from "devextreme/ui/validation_engine";
 import notify from 'devextreme/ui/notify';

 @Component({
   selector: 'app-simple-lookup-add-edit',
   templateUrl: './simple-lookup-add-edit.component.html',
   styleUrls: ['./simple-lookup-add-edit.component.css']
 })
 export class SimpleLookupAddEditFormComponent implements OnInit {

   newSystemList: {};
   isEditMode:boolean = true;
   selectedSystemList: any;
   title: string;
   saveButtonText: string;
   isPopupVisible:boolean = false;
   entityId:any;

   constructor(
     protected _systemListTitle : string,
     protected _svc: SimpleLookupBaseService,
     protected _router: Router,
     protected _route: ActivatedRoute
   ) 
     {}
 ............
 .....
 }

1 个答案:

答案 0 :(得分:2)

  

错误:无法解析SimpleLookupAddEditFormComponent的所有参数    在C:/ Users / lastr / Source / Repos / SMATA / Code / ng / smata-ng / src / app / system-    list / simple-lookup-add-edit / simple-lookup-add-edit.component.ts:(?,[object    对象],[对象对象],[对象对象])。

错误消息中的?问号表明构造函数中的哪个参数未知。

constructor(
 protected _systemListTitle : string,
 protected _svc: SimpleLookupBaseService,
 protected _router: Router,
 protected _route: ActivatedRoute
) 

第一个参数正在触发?问号。

类型string不是可注入类型。角注入器使用参数的类型来推断应使用的injectable提供程序。

要注入string参数,您必须在NgModule定义之一中提供令牌。

export const LIST_TITLE: InjectionToken<string> = new InjectionToken<string>('LIST_TITLE');

@NgModule({
   providers: [{provide: LIST_TITLE, useValue: 'My List Title'}]
})

现在,您可以将令牌手动注入到构造函数中。

constructor(
 @Inject(LIST_TITLE) protected _systemListTitle : string,
 protected _svc: SimpleLookupBaseService,
 protected _router: Router,
 protected _route: ActivatedRoute
)