要忽略空格，可以自定义验证器，将输入值与修剪后的输入值进行比较。以下是一个示例：

import { AbstractControl, ValidatorFn } from '@angular/forms';

export function minLengthValidator(minLength: number): ValidatorFn {
  return (control: AbstractControl): {[key: string]: any} | null => {
    const inputTrimmed = (control.value || '').trim(); // 修剪输入值
    const isValidLength = inputTrimmed.length >= minLength;
    return isValidLength ? null : { 'minLength': { 'requiredLength': minLength } };
  };
}

然后，可以在表单控件定义中使用自定义验证器：

import { Component } from '@angular/core';
import { FormControl, FormGroup } from '@angular/forms';
import { minLengthValidator } from './min-length-validator';

@Component({
  selector: 'app-root',
  template: `
    

      
        Name:
        
      

      

        Name must have at least {{ minLength }} non-space characters.
      

      Submit
    
  `,
})
export class AppComponent {
  readonly minLength = 3;

  readonly form = new FormGroup({
    name: new FormControl('', [minLengthValidator(this.minLength)]),
  });
}