Question

我创建了一个服务，以便将全局变量保存为angular。

import { Injectable } from "@angular/core";
import { BehaviorSubject } from "rxjs";
@Injectable()
@Injectable({
  providedIn: "root"
})
export class SharedService {
  private experimentIdSource = new BehaviorSubject("noId");
  currentExperimentId = this.experimentIdSource.asObservable();

  constructor() {}

  changeExperimentId(experimentId: string) {
    this.experimentIdSource.next(experimentId);
  }
}

像这样，我可以在另一个组件中使用它，并查看变量是否已更改。只需将其写入ngOnInit（）的正确组件中即可：

  ngOnInit() {
    this.shared.currentExperimentId.subscribe(
      currentExperimentId => (this.currentExperimentId = currentExperimentId)
    );
  }

实际上，根据变量的值，我使用 ngIf =“ currentExperimentId！=='noId'”

在html中显示一些除法/元素

但是，当我重新加载页面时，该变量被重新初始化，并且不再看到除法/元素。 * 因此，我将变量像这样存储在sessionStorage中：

import { Injectable } from "@angular/core";
import { BehaviorSubject } from "rxjs";
@Injectable()
@Injectable({
  providedIn: "root"
})
export class SharedService {
  previousExperimentId = sessionStorage.getItem("currentExperimentId")
    ? sessionStorage.getItem("currentExperimentId")
    : "noId";
  private experimentIdSource = new BehaviorSubject(this.previousExperimentId);
  currentExperimentId = this.experimentIdSource.asObservable();

  constructor() {}

  changeExperimentId(experimentId: string) {
    sessionStorage.setItem("currentExperimentId", experimentId);
    this.experimentIdSource.next(experimentId);
  }
}

我想知道是否还有其他方法或更好的方法？因为看起来就像在修补东西

具有sessionStorage和service的Angular全局变量

0 个答案: