如何在Angular7 FormArray字段中动态隐藏按钮？

<form [formGroup]="myForm">
  <div formArrayName="fields">
    <div *ngFor="let field of fields.controls; let i=index">
      <input [formControlName]="i">
      <button *ngIf="showButton(i)">按钮</button>
    </div>
  </div>
</form>

import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup, FormArray } from '@angular/forms';

@Component({
  selector: 'app-my-component',
  templateUrl: './my-component.component.html',
  styleUrls: ['./my-component.component.css']
})
export class MyComponent implements OnInit {
  myForm: FormGroup;

  constructor(private fb: FormBuilder) { }

  ngOnInit() {
    this.myForm = this.fb.group({
      fields: this.fb.array([])
    });

    // 添加初始字段
    this.addField();
  }

  get fields() {
    return this.myForm.get('fields') as FormArray;
  }

  addField() {
    this.fields.push(this.fb.control(''));
  }

  removeField(index: number) {
    this.fields.removeAt(index);
  }

  showButton(index: number) {
    // 根据条件判断是否显示按钮
    // 这里可以根据具体需求自定义逻辑
    return index % 2 === 0;
  }
}