Question

我需要将数据从一个组件传递到另一个组件，但是这样做很难。

我有一个Observable，我需要以Subject的身份通过，这是另一个“可观察的”。我怎么做？我目前使用的方法无法正常工作，因为它已进入 target组件 undefined。

这就是我所拥有的：

card.component.ts （全部从此处开始）

showBox(studentID) {
    const airportPickup = this.studentService.getCurrentStudents().pipe(
        map(snaps => {
            const student = snaps.find( s => s.studentID === studentID );
            return {
                requirePickup: student.pickup,
                whopickup: student.whoPickup
            };
        })
    );
    this.studentService.airportPickupDropoff.next(airportPickup);
}

如果我console.log() airportPickup我得到了对象。没有问题。问题是当我在其他组件中获取它时，我将其获取为undefined。

flight-info.component.ts （目标）

getAirportPickup() {
    this.studentService.airportPickupDropoff.subscribe(
        (apdata) => {
            this.airportPickupDropoff = apdata;
        },
        (e) => alert(e)
    );
}

服务，我有这个：

airportPickupDropoff = new Subject<any>();

Answer 1

您需要订阅可观察对象，或将其与RxJS运算符（例如tap）链接起来，以便将可观察对象的值分配给'Format Measured Dim rg As Range Dim cond1 As FormatCondition, cond2 As FormatCondition, cond3 As FormatCondition Set rg = Range("G14", Range("G14").End(xlDown)) 'clear any existing conditional formatting rg.FormatConditions.Delete 'define the rule for each conditional format Set cond1 = rg.FormatConditions.Add(xlCellValue, xlGreater, "=$D14+$E14+$H14") Set cond2 = rg.FormatConditions.Add(xlCellValue, xlLess, "=$D14-$F14") 'define the format applied for each conditional format With cond1 .Font.FontStyle = "Bold" .Font.Color = vbRed End With With cond2 .Font.FontStyle = "Bold" .Font.Color = vbRed End With主题。

选项1：

airportPickupDropoff

选项2：

showBox(studentID) {
  this.studentService.getCurrentStudents().pipe(
    map(snaps => {
      const student = snaps.find( s => s.studentID === studentID );
      return {
        requirePickup: student.pickup,
        whopickup: student.whoPickup
      };
    }),
  ).subscribe(response => {
    this.studentService.airportPickupDropoff.next(response);
  });
}

Answer 2

也许最好通过Subject而不是另一个Observable发送数据？

showBox(studentID) {
  ///...
  airportPickup.subscribe(apdata => this.studentService.airportPickupDropoff.next(apdata));
}

传递和展开可观察为主体的

2 个答案: