提交带有角度的表单到 Json 文件

Question

我想提交我的表单并有一种方法可以用我新创建的用户更新我的表。我从今天早上就卡住了。我已经有一个删除方法但错过了创建方法这是我的 html<div class="manage-content">  <div class="title">    <mat-icon class="user-icon">how_to_reg</mat-icon>    <h3>Create a user</h3>  </div>      <form [formGroup]="form" (ngSubmit)="onSubmit()">        Value : {{form.value | json}}        <div class="form">        <div class="leftSide">        <mat-form-field class="full-width-input" appearance="outline">          <input id="firstName" matInput placeholder="First name" formControlName="f_name" #f_name>          <mat-error *ngIf="isFieldInvalid('f_name')">            The first name you've entered is malformed.          </mat-error>        </mat-form-field>        <mat-form-field class="full-width-input" appearance="outline">          <input id="middleName" matInput placeholder="Middle name" formControlName="m_name" #m_name>          <mat-error *ngIf="isFieldInvalid('m_name')">            The middle name you've entered is malformed.          </mat-error>        </mat-form-field>        <mat-form-field class="full-width-input" appearance="outline">          <input id="lastName" matInput placeholder="Last name" formControlName="l_name" #l_name>          <mat-error *ngIf="isFieldInvalid('l_name')">            The last name you've entered is malformed.          </mat-error>        </mat-form-field>        <mat-form-field class="full-width-input" appearance="outline">          <input id="email" matInput placeholder="Email" formControlName="email" #email>          <mat-error *ngIf="isFieldInvalid('email')">            The email you've entered is malformed.          </mat-error>非常感谢你的帮助