我希望在循环中的每一轮中，当列表将根据当前的div更新时，显示一个列表作为选择中的选项。它在概念上起作用，但是html只根据列表中的最后一个条目更新一次，并且不会为每个循环旋转显示不同的列表

我的html

<div *ngFor="let item of listConstraint" [value]="item.id">
        <p>{{item.name_constraint}}</p>
        <select>
            <option *ngFor="let item1 of listConstraintDetails" [value]="item1.id">
                {{item1.name_constraint}}</option>
        </select>
    </div>

我的ts

import { Component, OnInit } from '@angular/core';
import { FormGroup, FormControl, Validators } from '@angular/forms';

import { Router } from '@angular/router';
import { HttpClient } from '@angular/common/http';
import { AjaxRequestService } from 'src/app/services/Request/ajax-request.service';
import { ConstraintKind } from 'src/app/class/constraintKind';
import { ConstraintDetails } from 'src/app/class/constraint-details';

@Component({
  selector: 'app-constraints',
  templateUrl: './constraints.component.html',
  styleUrls: ['./constraints.component.css']
})
export class ConstraintsComponent implements OnInit {
  constraintForm: FormGroup;
  listConstraint: ConstraintKind[] = [];
  listConstraintDetails: ConstraintDetails[] = [];
  constructor(private http: AjaxRequestService, private httpClient: HttpClient, private route: Router) {

  }

  ngOnInit(): void {
    this.GetConstraintsKind();
  }
  GetConstraintsKind() {
    return this.http.GetConstraintsKind().subscribe(data => {
      this.listConstraint = data;
      data.forEach(element => {
        this.GetConstraintsDetails(element.id);
      })
      console.log(data);
    })
  }
  GetConstraintsDetails(constraintId) {
    return this.http.GetConstraintsDetails(constraintId).subscribe(data => {
      this.listConstraintDetails = data;
      console.log(data);
    })
  }
}

my functions ajax服务

  GetConstraintsKind() {
    return this.http.get<any>('http://localhost:11818/Api/Constraint/getConstraintKind', { headers: this.header });
  }
  GetConstraintsDetails(constraintId: number) {
    return this.http.get<ConstraintDetails[]>('http://localhost:11818/Api/Constraint/GetConstraintsDetails/' + constraintId);
  }

服务器运行良好，并且发送了正确的数据，但是html始终显示相同的列表，非常感谢您的任何帮助