Arrays Angular2从可观测数据获取数组大小
我有4个不同的数组,每个数组的长度不同。我需要计算array.length,才能知道当前选定数组中有多少步。我希望这是在代码中完成的,而不是在模板中,如果可能的话 step.service.tsArrays Angular2从可观测数据获取数组大小,arrays,angular,typescript,Arrays,Angular,Typescript,我有4个不同的数组,每个数组的长度不同。我需要计算array.length,才能知道当前选定数组中有多少步。我希望这是在代码中完成的,而不是在模板中,如果可能的话 step.service.ts public apiURL(){ if (this.heroID == 0){ this.stepsUrl = 'api/stepsLiftSensor'; } else if(this.heroID == 1){ this.stepsUrl = 'api/stepsBucketSe
public apiURL(){
if (this.heroID == 0){
this.stepsUrl = 'api/stepsLiftSensor';
} else if(this.heroID == 1){
this.stepsUrl = 'api/stepsBucketSensor';
} else if(this.heroID == 2){
this.stepsUrl = 'api/stepsEmptyBucketSensor';
} else if(this.heroID == 3) {
this.stepsUrl = 'api/stepsFullBucketSensor';
}
console.log(this.stepsUrl);
}
getSteps(): Observable<Step[]> {
return this.http.get(this.stepsUrl)
.map(response => response.json().data as Step[]);
}
getStep(id: number): Observable<Step> {
const url = `${this.stepsUrl}/${id}`;
return this.http.get(url)
.map(response => response.json().data as Step);
}
import { Injectable } from '@angular/core';
import { InMemoryDbService } from 'angular-in-memory-web-api';
import { Hero } from './hero.class';
import { Step } from './step.class';
import { HeroService } from "./hero.service";
import { StepService } from "./step.service";
import { ActivatedRoute, Params } from "@angular/router";
import 'rxjs/Rx';
@Injectable()
export class InMemoryDataService implements InMemoryDbService {
hero: Hero;
step: Step;
private heroService: HeroService;
private stepService: StepService;
private route: ActivatedRoute;
private location: Location;
constructor() {}
ngOnInit(): void {
this.route.params
.switchMap((params: Params) => this.heroService.getHero(+params['id']))
.subscribe(hero => this.hero = hero);
}
createDb() {
let heroes = [
{id: 1, name: 'Lift Sensor', path: 'stepsLiftSensor'},
{id: 2, name: 'Bucket Sensor', path: 'stepsBucketSensor'},
{id: 3, name: 'Empty Bucket'},
{id: 4, name: 'Full Bucket'}
];
let stepsLiftSensor = [
{id: 1, name: 'test1'},
{id: 2, name: 'test2'},
{id: 3, name: 'test3'},
{id: 4, name: 'test4'},
{id: 5, name: 'test5'}
];
let stepsBucketSensor = [
{id: 1, name: 'test1'},
{id: 2, name: 'test2'},
{id: 3, name: 'test3'},
{id: 4, name: 'test4'},
{id: 5, name: 'test5'}
{id: 6, name: 'test6'},
{id: 7, name: 'test7'},
{id: 8, name: 'test8'},
{id: 9, name: 'test9'},
{id: 10, name: 'test10'}
];
let stepsEmptyBucketSensor = [
{id: 1, name: 'test1'},
{id: 2, name: 'test2'},
{id: 3, name: 'test3'},
{id: 4, name: 'test4'},
{id: 5, name: 'test5'},
{id: 6, name: 'test6'}
];
let stepsFullBucketSensor = [
{id: 1, name: 'test1'},
{id: 2, name: 'test2'},
{id: 3, name: 'test3'},
{id: 4, name: 'test4'},
{id: 5, name: 'test5'}
];
return { heroes, stepsLiftSensor, stepsBucketSensor, stepsEmptyBucketSensor, stepsFullBucketSensor };
}
}
step.class.ts
export class Step {
id: number;
name: string;
}
很难理解你想要什么。但从我读了5遍后得到的信息来看,一旦获得了步骤,就应该存储长度,并在
next()
方法中使用该变量:
stepsLength: number = 0;
getSteps(): Observable<Step[]> {
return this.http.get(this.stepsUrl)
.map(response => response.json().data as Step[])
.do(steps => this.stepsLength = steps.length);
}
stepsLength:number=0;
getSteps():可观察{
返回this.http.get(this.stepsUrl)
.map(response=>response.json().data作为步骤[])
.do(步长=>this.stepsLength=步长.length);
}
很难理解你想要什么。但从我读了5遍后得到的信息来看,一旦获得了步骤,就应该存储长度,并在next()
方法中使用该变量:
stepsLength: number = 0;
getSteps(): Observable<Step[]> {
return this.http.get(this.stepsUrl)
.map(response => response.json().data as Step[])
.do(steps => this.stepsLength = steps.length);
}
stepsLength:number=0;
getSteps():可观察{
返回this.http.get(this.stepsUrl)
.map(response=>response.json().data作为步骤[])
.do(步长=>this.stepsLength=步长.length);
}
您应该修改服务本身以返回数组的长度和数据(我们称之为lengthFromService
)
您可以将该长度存储在.ts中的一个变量中(我们称之为arrLength
),并对该变量进行检查
在下一个()函数中,可以执行如下操作:
this.stepService.getStep(this.currentStep).subscribe(data => {this.mainStepText = data.name; this.arrLength = data.lengthFromService});
如果您需要更多帮助,请发布服务的代码,或向服务提供
数据的任何函数的代码。您应该修改服务本身以返回数组的长度和数据(我们称之为lengthFromService
)
您可以将该长度存储在.ts中的一个变量中(我们称之为arrLength
),并对该变量进行检查
在下一个()函数中,可以执行如下操作:
this.stepService.getStep(this.currentStep).subscribe(data => {this.mainStepText = data.name; this.arrLength = data.lengthFromService});
如果您需要更多帮助,请发布服务的代码,或向服务提供数据的任何函数的代码。在重新阅读您的答案并查看我的代码后,我最终解决了它,我只使用了
this.stepService.getSteps().subscribe(data => (this.stepsLength = data.length));
然后把它放到我的校准细节的构造函数中。component.ts.在重新阅读你们的答案并查看我的代码后,我最终解决了它,我只是使用了
this.stepService.getSteps().subscribe(data => (this.stepsLength = data.length));
并将其放入构造函数中,以获取我的校准详细信息。component.ts.我尝试过这样做,但当我将其传回时,它是未定义的。我调用:getArrayLength():number{返回this.stepsLength;}并将其存储在:private stepsLength:number=this.stepService.getArrayLength()中;我试着这么做,但当我把它传回去时,它还没有定义。我调用:getArrayLength():number{返回this.stepsLength;}并将其存储在:private stepsLength:number=this.stepService.getArrayLength()中;增加了两门课,这是你想看到的吗?是的,谢谢你的提问,我添加了一个关于我如何解决它的答案。增加了两门课,这是你想看到的吗?是的,谢谢你的提问,我添加了一个关于我如何解决它的答案。