动态图表:日期预期错误!在Angular 7项目中将数组用作数据源时
ASP中的Api项目动态图表:日期预期错误!在Angular 7项目中将数组用作数据源时,angular,dygraphs,Angular,Dygraphs,ASP中的Api项目 [Route("api/[controller]")] public class SampleDataController : Controller { ... [HttpGet("[action]")] public Array GetGraphData() { var tsData = timeFloatService_.GetLatestDataRecords(4
[Route("api/[controller]")]
public class SampleDataController : Controller
{
...
[HttpGet("[action]")]
public Array GetGraphData()
{
var tsData = timeFloatService_.GetLatestDataRecords(4790, DataRecordStatus.Live, DataRecordAbnormal.Normal, 1).Get();
object[][] result = tsData.Select(x => new object[] { x.Index.ToString("yyyy/MM/dd HH:mm:ss"), x.Value }).Take(10).ToArray();
return result;
}
在调用的角度项目中接收到的:
import { Component, OnInit, Inject } from '@angular/core';
import { HttpClient } from '@angular/common/http';
@Component({
selector: 'app-test',
templateUrl: './test.component.html',
styleUrls: ['./test.component.css']
})
export class TestComponent implements OnInit {
private forecasts: any;
constructor(http: HttpClient, @Inject('BASE_URL') baseUrl: string) {
http.get<any[]>(baseUrl + 'api/SampleData/GetGraphData').subscribe(result => {
this.forecasts = result;
}, error => console.error(error));
}
<p>
test works!
</p>
<pre>{{forecasts|json}}</pre>
<ng-dygraphs [data]="forecasts"
[options]=VALID OPTIONS NOT SHOWN FOR BREVITY
</ng-dygraphs>
不幸的是,这行不通!(除非我犯了错误。)
需要将DOM/Html页面中的字符串更改为日期,因为更改后的数组仍将日期显示为字符串 您需要从字符串创建日期对象。您可以使用rxjs
map
来实现这一点
例如:
import { of } from 'rxjs';
import { map } from 'rxjs/operators';
// ...
httpGet = of([
[
"2013/01/01 00:00:00",
58096
], [
"2013/01/02 00:00:00",
50893
]
]);
constructor() {
this.httpGet
.pipe(map(item => item.map(i => [ new Date(i[0]), i[1] ])))
.subscribe(result => console.log(result));
}
在您的例子中,您显然不会映射到单个日期对象,而是映射到由日期对象和值组成的数组
编辑:
好的,这里有一个更完整的例子:
或者实际上,通过在订阅回调中使用array.map
,您可以使事情变得更简单:
谢谢如何对多个字段(即日期字段、值1字段、值2字段等)进行管道传输,并且从可以创建100-500k行数据的数据库中读取的数据不会是文字。由于您的数据源是一个数组数组,因此示例中的“ds”不是字符串而是数组,您只需通过索引访问即可。所以一个
map(item=>[newdate(item[0]),item[1]])应该可以。构造函数(http:HttpClient,@Inject('BASE_URL')baseUrl:string){http.get(baseUrl+'api/SampleData/GetGraphData')。订阅(result=>{this.predictions=from(result)。管道(map(item=>[newdate(item[0]),item[1]]);},error=>console.error(error));上面将数组更改为以下{u-isScalar:false,“source”:{u-isScalar:false,“array”:[[“2013/01/01 00:00:00”,58096],“2013/01/02 00:00:00”,50893],上面的Dresch:我认为需要在html中修改数组,因为修改后的数组仍将日期显示为string@AndrewDay我添加了一个更适合您的案例的示例。
{
"_isScalar": false,
"source": {
"_isScalar": false,
"array": [
[
"2013/01/01 00:00:00",
58096
],
[
"2013/01/02 00:00:00",
50893
],
import { from } from 'rxjs';
import { map } from 'rxjs/operators';
// ...
// observable array
const dates = from([
"2013/01/01 00:00:00",
"2013/01/02 00:00:00"
]);
dates.pipe(map(ds => new Date(ds))).subscribe(date => console.log(date));
import { of } from 'rxjs';
import { map } from 'rxjs/operators';
// ...
httpGet = of([
[
"2013/01/01 00:00:00",
58096
], [
"2013/01/02 00:00:00",
50893
]
]);
constructor() {
this.httpGet
.pipe(map(item => item.map(i => [ new Date(i[0]), i[1] ])))
.subscribe(result => console.log(result));
}
this.httpGet
.subscribe(result => {
const converted = result.map(i => [ new Date(i[0]), i[1] ]);
console.log(converted);
});