错误 TS2322：类型 'Observable<string[]>' 不可分配给类型 'Observable<Sensors[]>'

Question

此错误：

错误 TS2322：类型"可观察"不可分配给类型 "可观察"。类型"string[]"不可分配给类型 "传感器[]"。类型"字符串"不可分配给类型"传感器"。

在此打字稿代码中显示：

import { Observable } from 'rxjs/Rx';
import { map, startWith } from 'rxjs/operators';
filteredSensors: Observable<Sensors[]>;
constructor(private fb: FormBuilder, private ws: SensorService
) {
this.myform= new FormGroup({
'sensors_id': this.fb.array([], Validators.required),
'unit_price': new FormControl('', [Validators.required, Validators.nullValidator]),
});
this.filteredSensors = this.myform.controls['sensors_id'].valueChanges
.pipe(
startWith(['']),
);
}
ngOnInit() {
this.ws.getAllSensors().subscribe(
sensors => {
this.sensors = sensors
}
);
}

在html中，我有这个：*ngFor="let sensor of filteredSensors | async | myPipe: sensors : 'sensor_serial': i"

我有这个管道：

import { Pipe, PipeTransform } from '@angular/core';
@Pipe({
name: 'myPipe'
})
export class MyPipe implements PipeTransform {
transform<T>(value: Sensors, list: T[], field: string, idx: number): T[] {
const filterValue = value[idx] ? value[idx].toString().toLowerCase() : ''; //correct this line of as per Sensors object
return list.filter(sensor => sensor[field].toLowerCase().indexOf(filterValue) === 0);
}
}

请问任何想法，如何解决此错误？

传感器.ts

export class Sensors {
sensorType_id: number;
sensortype_id: number;
sensors_id: string;
sensor_serial: string;
active: number;
sensordescription: string;
unit_price: number;
description: string;
note: string;
Sensor_id: number;
default_price: number;
client_id: string;
client_name: String;
constructor(obj: any) {
this.sensorType_id = obj && obj.sensortype_id || obj.sensorType_id;
this.sensortype_id = obj && obj.sensortype_id;
this.client_id = obj && obj.client_id;
this.sensor_serial = obj && obj.sensor_serial;
this.sensors_id = obj && obj.sensors_id;
this.active = obj && obj.active;
this.sensordescription = obj && obj.sensordescription;
this.unit_price = obj && obj.unit_price;
this.description = obj && obj.description;
this.note = obj && obj.note;
this.Sensor_id = obj && obj.Sensor_id;
this.default_price = obj && obj.default_price;
this.client_name = obj && obj.client_name;
}
}

和 ws 传感器服务：

public getAllSensors(): Observable<Sensors[]> {
let headers = new Headers();
headers.append('x-access-token', this.auth.getCurrentUser().token);
return this.http.get(Api.getUrl(Api.URLS.getAllSensors), {
headers: headers
})
.map((response: Response) => {
let res = response.json();
if (res.StatusCode === 1) {
this.auth.logout();
return false;
} else {
return res.StatusDescription.map(sensors => {
return new Sensors(sensors);
});
}
});
}

Answer 1

您的Pipe存在类型问题。在 Pipe 中，您说它会在String上运行，但您传递Sensors.因此，更改Pipe的argumenttype并在Pipe内更改您的业务登录，

@Pipe({
name: 'myPipe'
})
export class MyPipe implements PipeTransform {
transform(items: string[], value: string): any[] {
if (!items) {
return [];
}
let array =  items.filter(item => item == value);
return  items.filter(item => item == value);
}
}

在网页中

*ngFor="let sensor of filteredSensors | async | myPipe: i"

注意：上面的"i"是应用过滤器的值。

工作副本在这里 - https://stackblitz.com/edit/angular-pipe-on-array