在Ionic中条件变为假后如何停止恢复和暂停事件？

Question

我正在使用恢复和暂停事件来知道应用程序何时在后台和前台运行。这里tm是当前系统时间，stym和etym是开始和结束时间。我希望我的恢复和暂停事件在stym和etym之间运行。当条件变为假时，恢复和暂停事件应停止。

const promise = new Promise(() => {
           
            if ((tm >= stym) && (etym >= tm))  //condition for start and end time
            {
             
              this.platform.resume.subscribe((e) => {
                this.resumetime = new Date();
                alert(this.resumetime);
                alert("resume called");
              });
                 if(etym >= tm){
              this.platform.pause.subscribe((e) => {
                this.pausetime = new Date();
                alert(this.pausetime);
                alert("pause called");
              });
            }
            else{
              this.platform.pause.unsubscribe();
            }

              this.time = (this.resumetime - this.pausetime) / 60000; // time b/w pause and resume
              alert(this.time);
              this.prall = this.prall + this.time; // total sum of resume and pause

              this.parray = [this.pausetime];
              this.rarray = [this.resumetime];
              var mn = new Date().getMinutes(); // getting presenttime minute
              var min = this.pausetime.getMinutes(); // getting pause time minute
              if ((mn - min) > 2)   // if pause is more than 2 min
              {
                this.localNotifications.schedule({
                  id: 1,
                  title: 'Attention',
                  text: 'come back and continue your study',
                  trigger: { at: new Date(new Date().getTime() + 5 * 1000) },
                  data: { mydata: 'reminder for you' },
                  led: 'FF0000',
                  vibrate: true
                });

              }
            }
            else { 
              console.log("over");
              this.platform.resume. unsubscribe();
              this.platform.pause.unsubscribe();
            }
          })
          promise.then(() => {
            // here  
            console.log("promise then");
            var sve = {
              pause: this.pausetime, resume: this.resumetime, id: data.data._id,
              prall: this.prall, parray: this.parray, rarray: this.rarray
            }
            // save pause and resume time and prall
            this.authService.respau(sve).subscribe(data => {
              if (data.success) {
                alert('success');
              } else {
                alert('error');
              }
            })
                
          });
          promise.catch((err) => {
            console.log("error");
          });