创建mid列数未知的Mat-table

let data = [
  { name: 'Alice', age: 30, city: 'New York' },
  { name: 'Bob', age: 25, city: 'Los Angeles' },
  // 更多数据...
];

let columns = Object.keys(data[0]);

<table mat-table [dataSource]="dataSource">
  <!-- 动态生成列 -->
  <ng-container *ngFor="let column of columns" [matColumnDef]="column">
    <th mat-header-cell *matHeaderCellDef> {{ column }} </th>
    <td mat-cell *matCellDef="let element"> {{ element[column] }} </td>
  </ng-container>

  <tr mat-header-row *matHeaderRowDef="columns"></tr>
  <tr mat-row *matRowDef="let row; columns: columns;"></tr>
</table>

import { MatTableDataSource } from '@angular/material/table';

export class MyComponent {
  dataSource = new MatTableDataSource(data);
  columns = Object.keys(data[0]);
}

if (data.length > 0) {
  this.columns = Object.keys(data[0]);
} else {
  this.columns = []; // 设置默认空列
}