为什么角表没有排序？

如何解决为什么角表没有排序？

这是table.component.ts文件。我想对表进行排序，例如在angular的示例中： https://material.angular.io/components/sort/overview，但在这种情况下，它没有排序。我不知道问题是什么。

首先，我将child.module.ts导入模块：

import { MatTableModule } from '@angular/material/table';
import { MatSortModule } from "@angular/material/sort";

导入模块：

    import: [
        MatTableModule,MatSortModule
]

这是table.component.ts文件：

 import { MatPaginator } from '@angular/material/paginator';
    import { MatSort } from '@angular/material/sort';
    import { MatTableDataSource } from '@angular/material/table';

    export interface PeriodicElement {
      timestamp: string;  
      key: string;
      value: number;
    
    }
export class TableComponent implements OnInit {

  
  loadingData = false;


  displayedColumns: string[] = ['data','key','value'];

  ELEMENT_DATA: PeriodicElement[] = new Array<PeriodicElement>();

  dataSource = new MatTableDataSource<PeriodicElement>(this.ELEMENT_DATA);

  datastructure: Array<dataschema> = [];

  sortedData: PeriodicElement[];


   //sort data 
  @ViewChild(MatPaginator,{ static: false }) paginator: MatPaginator;  
  @ViewChild(MatSort,{ static: false }) sort: MatSort; 

  constructor(private Service: Service) {
this.sortedData = this.ELEMENT_DATA.slice() }

  exportTable() {
    Tableutil.exportTabletoExcel("ExampleTable");
  }


  ngAfterViewInit(): void {
    this.dataSource.sort = this.sort;
    
}


  ngOnInit(): void {
    this.dataSource.paginator = this.paginator;
    this.dataSource.sort = this.sort;

    
    this.loadingData = true;

    this.Service.getContent().then(results => {

      this.datastructure = results;
     
     
      this.loadingData = false;
      
      
      for (let i = 0; i < this.datastructure.length; i++) {

        

        cut off code 
      }

    })

  }

sortData(sort: Sort) {
const data = this.ELEMENT_DATA.slice();
if (!sort.active || sort.direction === '') {
  this.sortedData = data;
  return;
}
this.sortedData = data.sort((a,b) => {
  const isAsc = sort.direction === 'asc';
  switch (sort.active) {
    case 'data': return compare(a.data,b.data,isAsc);
    case 'key': return compare(a.key,b.key,isAsc);
    case 'value': return compare(a.value,b.value,isAsc);
    default: return 0;


   }
    })

    
  }
      
    
}
function compare(a: number | string,b: number | string,isAsc: boolean) {
  return (a < b ? -1 : 1) * (isAsc ? 1 : -1);
}

html视图：

    <div *ngIf="!loadingData" class="mat-elevation-z8">
       <table id="ExampleTable" mat-table matTableExporter [dataSource]="dataSource"  matSort (matSortChange)="sortData($event)" class="mat-elevation-z8">
<!--Example Column/Row-->



<ng-container matColumnDef="data">
      <th mat-header-cell mat-sort-header *matHeaderCellDef > data </th>
      <td mat-cell *matCellDef="let element"> {{element.data}} </td>
    </ng-container>

    </table>
    </div>

解决方法

问题出在ViewChild中。有一个错字。您正在尝试获取 MatSort 。但这是 matSort 。

TS

@ViewChild(MatSort,{ static: false }) sort: MatSort; 

HTML

<table id="ExampleTable" mat-table matTableExporter [dataSource]="dataSource"  matSort class="mat-elevation-z8">

相反，请尝试以下代码，

TS

@ViewChild('exampleTableTableSort,{ static: false }) sort: MatSort; 

HTML

<table #exampleTableTableSort='matSort' id="ExampleTable" mat-table matTableExporter [dataSource]="dataSource"  matSort class="mat-elevation-z8">

,

如果您的数据在*ngIf下，Angular无法到达它，那么我建议给Angular喘一口气（将dataSource.paginator和this.dataSource.sort包含在setTimeout中

this.Service.getContent().then(results => {
    this.datastructure = results;
    this.loadingData = false;
    setTimeout(()=>{
      this.dataSource.paginator = this.paginator;
      this.dataSource.sort = this.sort;
    })
})

无论如何，Angular会为您排序数据，我无法理解您的函数排序和变量sortedData。您只需要相等的datasource.data即可响应您的API