我对angular2完全陌生。我的问题是我通过 ng2-charts lib 创建了一个条形图,并使用 angularfire2 将其链接到 firebase。我有 2 个组件和一个服务,用于向我的 firebase 数据库发送和接收数据。我能够通过 my 将数据从一个组件发送doctor-local.component.ts
到 firebasedata.service.ts
并在 my 上接收它,并使此处的数据与 firebase 数据库中的值的更改保持同步,并使用事件绑定doctor-expert.component.ts
在同一组件中实时显示。(ngModelChange)
条形图也在这个组件中。
这是我的expert.component.ts
和doctor-expert.component.html
import {Component} from '@angular/core';
import {DataService} from '../data.service';
import {FirebaseObjectObservable} from 'angularfire2';
@Component({
selector: 'app-doctor-expert',
templateUrl: './doctor-expert.component.html',
styleUrls: ['./doctor-expert.component.css']
})
export class DoctorExpertComponent {
public items: FirebaseObjectObservable<any>;
public barChartOptions: any = {
scaleShowVerticalLines: false,
responsive: true
};
public barChartLabels: string[] = ['RBC Count', 'WBC Count', 'Haemoglobin'];
public barChartType: string = 'bar';
public barChartLegend: boolean = true;
rbc: number;
wbc: number;
haemo: number;
public barChartData: any[] = [
{data: [75, 59, 80], label: 'Current Count'},
{data: [28, 48, 40], label: 'Average Normal Count'}
];
constructor(private dataService: DataService) {
this.items = this.dataService.messages;
this.items.subscribe(data => {
this.rbc = parseInt((data.rbccount), 10);
this.wbc = parseInt((data.wbccount), 10);
this.haemo = parseInt((data.haemocount), 10);
});
this.barChartData = [
{data: [this.rbc, this.wbc, this.haemo], label: 'Current Count'},
{data: [50, 50, 50], label: 'Average Normal Count'},
];
}
public chartClicked(e: any): void {
console.log(e);
}
public chartHovered(e: any): void {
console.log(e);
}
}
<ul class="list-group container">
<li class="list-group-item">RBC Count: {{(items | async)?.rbccount}} </li>
<li class="list-group-item">WBC Count: {{(items | async)?.wbccount}} </li>
<li class="list-group-item">Haemoglobin Count: {{(items | async)?.haemocount}} </li>
</ul>
<div class="container">
<div style="display: block">
<canvas baseChart
[datasets]="barChartData"
[labels]="barChartLabels"
[options]="barChartOptions"
[legend]="barChartLegend"
[chartType]="barChartType"
(chartHover)="chartHovered($event)"
(chartClick)="chartClicked($event)"></canvas>
</div>
</div>
这是我的data.service.ts
import {Injectable} from '@angular/core';
import 'rxjs/Rx';
import {AngularFire, FirebaseObjectObservable} from 'angularfire2';
@Injectable()
export class DataService {
public messages: FirebaseObjectObservable<any>;
constructor( public af: AngularFire ) {
this.messages = this.af.database.object('data');
}
sendData(value1, value2, value3) {
const message = {
rbccount: value1,
wbccount: value2,
haemocount: value3
};
this.messages.update(message);
}
sendrbc(value){
const message = {
rbccount: value
};
this.messages.update(message);
}
sendwbc(value2){
const message = {
wbccount: value2
};
this.messages.update(message);
}
sendhaemo(value3){
const message = {
haemocount: value3
};
this.messages.update(message);
}
}
“this.items = this.dataService.messages”从数据库中接收代码,subscribe 方法从 observable 中获取值。现在我想更新在 barChartData 中收到的这个值,并使其与数据库中的更改保持同步。这样每次通过的数据doctor-local.component.ts
发生变化,数据库和条形图都会立即发生变化。我尝试在构造函数本身中这样做,但数据根本不显示在条形图中,更不用说不断更新了。