import { Component } from '@angular/core';
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
 
  _inputVal;
 
  set inputVal(val) {
    this._inputVal = val;
    this.inputChange();
  };
 
  get inputVal() {
    return this._inputVal;
  }
 
  inputChange(val) {
    console.log(val);
  }
}

import {
?Validators,
?FormGroup,
?FormBuilder
} from '@angular/forms';
 

?? ?validateForm: FormGroup;
?? ?constructor(private fb: FormBuilder,private ref: ChangeDetectorRef,private private) {}

? data = {
? ?? ?name: [null, [Validators.required]], //Validators.required 表示验证（必填）
? };
? ngOnInit(): void {
?? ?this.validateForm = this.fb.group(this.data);
?? ?// 监听整个表单的变化
? ? this.validateForm.valueChanges.subscribe(data => console.log('form', data));
?? ?// 单个control 变化
? ? this.validateForm.get('name').valueChanges.subscribe(data => console.log('solo', data));
? }