Javascript ionic3如何在ErrorHandlerService中注入服务/提供者

问题:

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当我在ErrorHandlerService中注入ConfigService来祝酒时，给我一个错误：ErrorHandlerService.ts:36 发生错误：Error:Uncaught（承诺中）：TypeError:无法读取未定义的属性“\u appLog”

 export class ErrorHandlerService implements ErrorHandler {

      private _appLog: ConfigService;
      constructor (private injector: Injector) {
        setTimeout(() => {
          this._appLog = injector.get(ConfigService);
        }, 0);
      }
      handleError(error: Error | HttpErrorResponse) {

          if (error instanceof HttpErrorResponse) {
              if (!navigator.onLine) {
                console.log('Please, check your internet connection');

              } else if(error.status === 401){
                console.log(error.message);
                this._appLog.presentToast();

              }else {
                console.log(error.message);
              }
            } else {
              console.log('Not Http Error');
          }
          // Log the error anyway
          console.error('It happens: ', error);
      }  
    }


    @Injectable()
    export class ConfigService {

        constructor(private storage: Storage){
        }

        presentToast(){
            console.log("test");
        }
    }


 getUsers(){
        let promise = new Promise((resolve, reject) => {
            let apiURL = `${this.configS.apiRootV1}/users`;
            this.http.get(apiURL).toPromise()
                .then((res) => {

                    console.log(res);
                    resolve(res);

                }).catch(this.errorHandlerService.handleError);
        });
        return promise;
    }

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在handleError函数中，“this”未定义。尝试使用“绑定”发送“this”的值：

.catch(this.errorHandlerService.handleError.bind(this.errorHandlerService));

---

在handleError函数中，“this”未定义。尝试使用“绑定”发送“this”的值：

.catch(this.errorHandlerService.handleError.bind(this.errorHandlerService));