在angular 6的应用中添加新组件并在该组件中添加树结构时出错

Question

import { CommonModule } from '@angular/common';
import { HttpClient, HttpClientModule } from '@angular/common/http';
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { TranslateLoader, TranslateModule } from '@ngx-translate/core';
import { TranslateHttpLoader } from '@ngx-translate/http-loader';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { AuthGuard } from './shared';
import { CookieService} from 'ngx-cookie-service';
import {SelectModule} from 'ng-select';

import { NgbModule } from '@ng-bootstrap/ng-bootstrap';
import { ReactiveFormsModule } from '@angular/forms';

import {ToastrModule} from 'ngx-toastr';
//import { TreeComponent } from './tree/tree.component';
import { MatTreeModule, MatIconModule, MatButtonModule } from '@angular/material';


// AoT requires an exported function for factories
export const createTranslateLoader = (http: HttpClient) => {
    /* for development
    return new TranslateHttpLoader(
        http,
        '/start-angular/SB-Admin-BS4-Angular-6/master/dist/assets/i18n/',
        '.json'
    ); */
    return new TranslateHttpLoader(http, './assets/i18n/', '.json');
};

@NgModule({
    
    imports: [
        CommonModule,
        BrowserModule,
        BrowserAnimationsModule,
        HttpClientModule,
        NgbModule.forRoot(),
        // NgMultiSelectDropDownModule.forRoot(),
        // NgSelectModule,
        // FormsModule,
        SelectModule,
        ToastrModule.forRoot(),
        TranslateModule.forRoot({
            loader: {
                provide: TranslateLoader,
                useFactory: createTranslateLoader,
                deps: [HttpClient]
            }
        }),
        AppRoutingModule,
        ReactiveFormsModule, 
        MatTreeModule,
        MatIconModule,
        MatButtonModule
    ],
    declarations: [AppComponent],
    providers: [AuthGuard, CookieService],
    bootstrap: [AppComponent]
})
export class AppModule {}

.example-tree-invisible {
    display: none;
  }
  
  .example-tree ul,
  .example-tree li {
    margin-top: 0;
    margin-bottom: 0;
    list-style-type: none;
  }
  

<mat-tree [dataSource]="nestedDataSource" [treeControl]="nestedTreeControl" class="example-tree">
  <mat-tree-node *matTreeNodeDef="let node" matTreeNodeToggle>
    <li class="mat-tree-node">
      <button mat-icon-button disabled></button>
      {{node.filename}}:  {{node.type}}
    </li>
  </mat-tree-node>

  <mat-nested-tree-node *matTreeNodeDef="let node; when: hasNestedChild">
    <li>
      <div class="mat-tree-node">
        <button mat-icon-button matTreeNodeToggle
                [attr.aria-label]="'toggle ' + node.filename">
          <mat-icon class="mat-icon-rtl-mirror">
            {{nestedTreeControl.isExpanded(node) ? 'expand_more' : 'chevron_right'}}
          </mat-icon>
        </button>
        {{node.filename}}
      </div>
      <ul [class.example-tree-invisible]="!nestedTreeControl.isExpanded(node)">
        <ng-container matTreeNodeOutlet></ng-container>
      </ul>
    </li>
  </mat-nested-tree-node>
</mat-tree>

感谢您提前帮助我。

我在Angular JS 6中的biggener需要您的帮助，因为我已尝试将树实现到此应用程序链接中，如下所示：-

https://material.angular.io/components/tree/overview

在实施过程中遇到问题时，任何人都可以帮助我摆脱该错误。完成检查元素后，请在浏览器中找到附加的错误日志。

{错误错误：“未捕获（承诺）：错误：模块'TreeModule'声明了意外的值'TreeComponent'。请添加@ Pipe / @ Directive / @ Component批注。 语法错误}

如果您需要其他任何检查问题的信息，请告诉我。

谢谢您的回答。