相关疑难解决方法(0)

我有一个包含少量数据字段和两个按钮的表单.我想仅在用户对表单进行一些更改时才启用按钮.我尝试过使用:

this.form.valueChanges.subscribe(data => console.log('form changes', data));

但是,当表单加载时,最初会检测到更改.有没有其他方法来检查表单中的任何更改.我希望仅在用户对字段进行更改时才调用它,而不是在表单加载时调用.以下是我的html和打字稿代码:

profile.html:

<section>
    <div>
        <form [formGroup]="form">
            <fieldset>
                <div class="panel-group m-l-1 m-r-1 accordion vertical-scroll" id="">
                    <div class="form-group required no-gutter">
                        <label for="firstname"> First Name:</label>
                        <div class="col-md-7 col-lg-6">
                            <input type="text" class="form-control" id="firstname" placeholder="" name="firstname" title="firstname" formControlName="firstname" size="128" aria-required="true" maxlength="35">
                        </div>
                    </div>
                </div>

            </fieldset>
            <div>
                <button class="btn btn-primary" type="button" (click)="save()">Save</button>
                <button class="btn btn-primary" type="button" (click)="cancel()">Cancel</button>
            </div>
        </form>
    </div>
</section>

profile.component.ts:

export class ProfileComponent implements OnInit, AfterViewInit, OnChanges {
    public form: FormGroup;

    constructor(private formBuilder: FormBuilder, private app: Application) { …