Question

我在传递actionmenuline的值时遇到问题。 actionmenuline值传入的是不确定的，我不确定发生了什么。

服务正在为第一个值而不是第二个值传递正确的代码。我想知道我在getAction调用中是否做错了什么，没有得到正确的对象。

这是我得到的错误：->

无法读取未定义的属性“ subscribe” 在新的ActionViewComponent（actionview.component.ts：68）上，第68行指向this.actionMenuSubscription

操作视图组件

export class ActionViewComponent implements OnInit, OnDestroy {

    // User Fields
    currentUser: User;
    users: User[] = [];
    currentUserSubscription: Subscription;


    // Menu Lines
    currentActionMenuLine: ActionMenuLine;
    actionMenuLines: ActionMenuLine[] = [];
    actionMenuSubscription: Subscription;

    dataSource: any = new MatTableDataSource(ACTION_DATA);

    constructor(
        private authenticationService: AuthenticationService,
        private actionService: ActionService,
        private menuService: MenuService,
    ) {
        this.currentUserSubscription = this.authenticationService.currentUser.subscribe(user => {
          this.currentUser = user;
        });

        this.actionMenuSubscription = this.menuService.currentActionMenuLine.subscribe(actionmenuline => {
          this.currentActionMenuLine = actionmenuline;
        });
    }

   public getActions() {
      this.actionService.getAction(this.currentUser, this.currentActionMenuLine).
      subscribe((data: any) => {
          this.dataSource = data;
        });
    }

}

行动服务

export class ActionService {

  public apiURL = 'http://localhost:15217/api/actions/launchaction';
  public currentUser: Observable<User>;
  public currentAction: Observable<Action>;
  private currentActionSubject: BehaviorSubject<Action>;
  public ActionMenuLine: Observable<ActionMenuLine>;


    constructor(private http: HttpClient) {
      this.currentActionSubject = new BehaviorSubject<Action>(JSON.parse(localStorage.getItem('currentAction')));
      this.currentAction = this.currentActionSubject.asObservable();
    }
      // Http Options
  httpOptions = {
    headers: new HttpHeaders({
      'Content-Type': 'application/json'
    })
  };

  getAction( user: User, actionmenuline: ActionMenuLine) {
      return this.http.post<User[]>(this.apiURL,
        {
            SessionID:  user.userEnv.sessionId,
            ActionTag: actionmenuline.targetActionTag
       })
        .pipe(
          retry(1),
          catchError(this.handleError)
        );
  }

菜单服务

export class MenuService {

public currentUser: Observable<User>;
private currentActionMenuLineSubject: BehaviorSubject<ActionMenuLine>;
public currentActionMenuLine: Observable<ActionMenuLine>;
ActionMenuSubscription: any;

constructor(private http: HttpClient) { }

loadActionMenu(user: User): Observable<ActionMenuLine[]> {
    return this.http.get<ActionMenuLine[]>(`/menu/getlines/`, {
        params : {
            userId: user.id,
            sessionId: user.userEnv.sessionId
        }
    }).pipe(map( MenuLines => {
        return this.debugLines(MenuLines) as ActionMenuLine[];
    }));
}

debugLines(lines: ActionMenuLine[]){

    let i:number = 0;
    let kids:ActionMenuLine[];

    for( let i:number = 0; i< lines.length; i++ ){
        let j:ActionMenuLine = lines[i];
        kids = j.children;
    }

    return lines;
}

loadAboutSyntelic():Observable<string[]> {
    return this.http.get<string[]>('usersettings/aboutsyntelic/').pipe(map( AboutSyntelic => {
        return AboutSyntelic as string[];
    }));
}

loadMimic(sessionId: string):Observable<string[]> {
    return this.http.get<string[]>("usersettings/mimicdata/",{
        params: {
            sessionId: sessionId
        }
    }).pipe(map(ids => ids as string[]));
}

mimic(userId: string, sessionId: string){
    return this.http.get<any>("usersettings/mimic/",{
        params : {
            userId: userId,
            sessionId: sessionId
        }
    }).pipe(map( res => {
        return res as User
    }));
}

Answer 1

currentActionMenuLine在 MenuService 中定义，但在整个类中均未分配值。

MenuService.ts

public currentActionMenuLine$: Observable<ActionMenuLine>;

服务正在为第一个值而不是第二个值传递正确的代码。

那是因为也许您正在 AuthenticationService 中为其分配一个值，但问题中没有出现。

检查您的 AuthenticationService 类，然后在此处为currentActionMenuLine执行相同操作（添加初始值）。

PS：

通常，我们在Observable变量名称的末尾使用 $ 符号。

Answer 2

将服务修改为

getAction( user: User, actionmenuline: ActionMenuLine): Observable<any> {
      return this.http.post<User[]>(this.apiURL,
        {
            SessionID:  user.userEnv.sessionId,
            ActionTag: actionmenuline.targetActionTag
       })
  }

在组件中以及组件中使用它而不是在服务中添加管道

public getActions() {
  this.actionService.getAction(this.currentUser, this.currentActionMenuLine)
    .pipe(retry(1))
    .subscribe((data: any) => {
         this.dataSource = data;
   });
}

Answer 3

在currentActionMenuLine中没有用于初始化menuService的代码。您已将其键入为Observable，但由于该值仍为undefined，因此在运行时不会起作用。

无法读取未定义角度7的属性“订阅”

3 个答案: