Angular7里面实现 debounce search

项目需求：

　　全局搜索 + 防抖提高性能

技术：

　　[(ngModel)] [(ngModelChange)] Rxjs( Subject)

代码展示：

// html
     <input type="text" placeholder="Search" [(ngModel)]="globalSearchContent" (ngModelChange)="globalSearch()">

// xx.component.ts
import { Observable, combineLatest, Subject } from 'rxjs';
import { distinctUntilChanged, debounceTime } from 'rxjs/operators';


private searchStream = new Subject<string>();

ngOnInit() {
// 订阅
    this.initGlobalSearchSubscription();
}

  ngOnDestroy() {
// 取消订阅
    this.searchStream.unsubscribe();
  }

  private async initGlobalSearchSubscription() {
    this.projectId = await this.localStorageService.getItem('currentProject');
    this.searchStream.pipe(
      debounceTime(400),
      distinctUntilChanged())
    .subscribe(async(searchContent) => {
      const searchResult = await this.projectService.globalSearch(this.projectId, searchContent).toPromise();
      this.searchMenuList = searchResult.body;
    });
  }

  private globalSearch() {
　　// 消息发送
    this.searchStream.next(this.globalSearchContent);
  }