通过将http请求放在Angular生命周期的ngOnInit方法中，确保http请求完成后再绘制表格，以确保数据能够正常加载。

示例代码：

import { Component, OnInit } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Component({
  selector: 'app-mycomponent',
  templateUrl: './mycomponent.component.html',
  styleUrls: ['./mycomponent.component.css']
})
export class MycomponentComponent implements OnInit {
  rowData: any[];

  constructor(private http: HttpClient) { }

  ngOnInit(): void {
    this.http.get('https://myapi.com/data').subscribe(
      data => {
        this.rowData = data;
      },
      error => {
        console.log(error);
      },
      () => {
        this.gridOptions.api.setRowData(this.rowData);
      }
    );
  }

  gridOptions = {
    //... your grid options
  };
}