我需要监听表单是否有任何变化，如果有变化则制作 enable/disable SAVE 按钮 | Angular

Question

在收听页面上的任何更改时遇到问题有一些信息，即使没有更改 SAVE 按钮激活点击

ngOnInit(): void {
        this.createConfigForm()

        this.configFilterForm.valueChanges.pipe(takeUntil(this.unsubscribeAll$)).subscribe(value => {
            value
        })
 }

<!-- ADD BUTTON -->
            <button
                *ngIf="isUpdate()"
                [disabled]="configFilterForm"
                mat-raised-button
                class="add-config-button"
                (click)="onSave()"
                trackClickSnowplow
                id="config-form_save_button"
            >
                <span>SAVE</span>
            </button>

我想我需要订阅，但没有找到可以订阅的地方

Answer 1

在您的 HTML 文件中；

<form [formGroup]="formAngular" (ngSubmit)="onSubmit()">
        <label>Name</label>
        <input type="text" formControlName="name">

        {{formAngular.controls.name.errors | json}}

        <p 
            *ngIf="formAngular.controls.name.errors?.required && formAngular.controls.name.touched && formSend">
            It is required your name
        </p>

    <input type="submit" value="Send"  />

    <p  *ngIf="formSend && !formAngular.valid">Form is not complete</p>

</form>

在您的组件 TS 文件中；

  formAngular: FormGroup;

  formSend: boolean;

  constructor() {
    this.formSend = false;
    this.formAngular = new FormGroup({
      name: new FormControl('', [
        Validators.required,
        Validators.maxLength(10)
      ])
  }

onSubmit() {
    this.formSend = true;
    console.log("Form value: ", this.formAngular.value);
  }


ngOnInit() {
    const controlName = this.formAngular.controls.name;
    controlName.valueChanges.pipe(debounceTime(500)).subscribe(value => {
      console.log("Your changes: ", value);
    });
  }

Answer 2

像现在一样收听表单更改，每次有更改时，启用按钮。单击按钮时禁用按钮，它将保持禁用状态，直到发生更改。类似于：

configFilterForm: FormGroup;
isDisabled = true;

constructor(private fb: FormBuilder) {
  this.configFilterForm = this.fb.group({
    input1: ['hello']
  });

  this.configFilterForm.valueChanges.pipe(
    takeUntil(this.unsubscribeAll$)
  ).subscribe(value => {
     this.isDisabled = false;
  });
}

和按钮：

<button [disabled]="isDisabled">Submit</button>

HERE'S A DEMO

顺便说一句，我看到你在按钮上调用了一些函数 *ngIf="isUpdate()"。请不要那样做，它们会在每次更改检测时被调用，并且确实会减慢您的应用程序。请改用变量！

我需要监听表单是否有任何变化，如果有变化则制作 enable/disable SAVE 按钮 | Angular

I need to listen if there any changes in the form, make enable/disable SAVE button if there changes or not | Angular

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