javascript - 如何在单击按钮时显示验证消息？

Question

您能告诉我如何在单击按钮时显示验证消息吗？这是我的代码 https://stackblitz.com/edit/angular-ugdbvg?file=src/app/app.component.html

我想在用户按下提交按钮时显示必需错误消息。

  <form novalidate [formGroup]="searchForm" class="calform">
      <section class="col-sm-6 bg-white  pl-20 pr-20">

      <div class="form-group col-sm-4 pl-0 error">
          <label class="field-title mb-5">name<span class="color-red fontWt">&nbsp;*</span></label>
          <input type="text" placeholder="Enter name" formControlName="name">
          <p class="message" [hidden]="searchForm.get('name')">Required</p>
        </div>

        <div class="form-group col-sm-4 pl-0 error">
          <label class="field-title mb-5">last name <span class="color-red fontWt">&nbsp;*</span></label>
          <input type="text" placeholder="Enter last name" formControlName="lastName">
          <p class="message" [hidden]="searchForm.get('lastName')">Required</p>
        </div>
        <button (click)="submitHandler()">submit</button>
      </section>
    </form>

js

this.searchForm = this.fb.group({
      name: ['', Validators.required],
          lastName: ['', Validators.required]

    });

Answer 1

添加以下行进行检查:

<span class="error" *ngIf="!!searchForm.controls.name.errors.required && (!!searchForm.controls.name.dirty || !!searchForm.controls.name.touched)">
    Name is required.
</span> 
<span class="error" *ngIf="!!searchForm.controls.lastName.errors.required && (!!searchForm.controls.lastName.dirty || !!searchForm.controls.name.touched)">
    lastName is required.
</span>

在你的 ts 文件中:

submitHandler() {
    if(this.searchForm.valid) {
        // Logic
    }
}

https://stackblitz.com/edit/angular-utvw23