Angular2 异常：主机中的 ngClass，"isn't a known native property"

Question

是否可以在主机内使用 "ngClass" 以获得 component/directive。

    @Component({
        selector: 'custom',
        template: `<div [ngClass]="classMap"></div> // I work
        <ng-content></ng-content>`,
        host: {
            '[ngClass]' : 'classMap' // I don't work!!!
        }
    })
    export class CustomComponent {
        constructor () {
            this.classMap = {
                custom: true
            };
        }
    }

在上面的示例中，ngClass 在模板中的 div 上正常工作。它添加了 "custom" class，但在尝试通过添加时抛出异常给主持人。

"Can't bind to 'ngClass' since it isn't a known native property"

直接在主机中设置 class 可以正常工作，例如；

host: {
    '[class.custom]' : 'classMap.custom'
}

所以会觉得ngClass可以吗？语法不正确？（可能！！！）:)

Answer 1

ngClass 是指令，主机绑定不支持指令。

    host: {
        '[ngClass]' : 'classMap' // I don't work!!!
    }

需要

    host: {
        '[class.className]' : 'className', 
        '[class]' : 'classNames' 
    }

其中 classNames 是 space 分隔列表类。

Answer 2

我遇到了同样的问题，但我可以通过在我的模块上导入一些模块来解决它：

import { RouterModule, Routes }   from '@angular/router';
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import {KSSwiperModule} from 'angular2-swiper';

import { DashboardComponent }     from './dashboard.component';
import {SwiperComponent} from "./swiper.component";

const routes: Routes =  [
  { path: 'dashboard',  component: DashboardComponent },
];

@NgModule({
  imports:      [
    RouterModule.forChild(routes),
    KSSwiperModule,
    BrowserModule,
    FormsModule,
    HttpModule
  ],
  declarations: [ DashboardComponent, SwiperComponent ]
})
export class DashboardModule { }

我的组件不使用 "host":

import { Component, ViewEncapsulation } from '@angular/core';

@Component({
  moduleId: "dashboard",
  selector: 'app-dashboard',
  templateUrl: 'dashboard.component.html',
  styleUrls: [ 'dashboard.component.scss' ],
  encapsulation: ViewEncapsulation.None
})
export class DashboardComponent {
  public isLandingHidden: boolean;

  showReasons() {
    this.isLandingHidden = true;
  }
}

Angular2 异常：主机中的 ngClass，"isn't a known native property"

Angular2 Exception: ngClass within a Host, "isn't a known native property"

ng-class

angular