重定向后的FormGroup验证

// 保存表单状态
localStorage.setItem('formState', JSON.stringify(this.formGroup.value));

// 恢复表单状态
const savedState = localStorage.getItem('formState');
if (savedState) {
  this.formGroup.setValue(JSON.parse(savedState));
}

// 保存表单状态到路由参数
this.router.navigate(['/target'], { queryParams: { formState: JSON.stringify(this.formGroup.value) } });

// 在目标页面恢复表单状态
this.route.queryParams.subscribe(params => {
  const savedState = params['formState'];
  if (savedState) {
    this.formGroup.setValue(JSON.parse(savedState));
  }
});

@Injectable({ providedIn: 'root' })
export class FormStateService {
  private formStateSubject = new BehaviorSubject<any>(null);

  setFormState(state: any) {
    this.formStateSubject.next(state);
  }

  getFormState() {
    return this.formStateSubject.asObservable();
  }
}

// 在组件中使用服务
constructor(private formStateService: FormStateService) {
  this.formStateService.getFormState().subscribe(state => {
    if (state) {
      this.formGroup.setValue(state);
    }
  });
}

// 在重定向前保存表单状态
this.formStateService.setFormState(this.formGroup.value);

import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup } from '@angular/forms';
import { Router } from '@angular/router';

@Component({
  selector: 'app-form',
  template: `
    <form [formGroup]="formGroup" (ngSubmit)="submitForm()">
      <input formControlName="name" placeholder="Name">
      <button type="submit">Submit</button>
    </form>
  `
})
export class FormComponent implements OnInit {
  formGroup: FormGroup;

  constructor(private fb: FormBuilder, private router: Router) {
    this.formGroup = this.fb.group({
      name: ['', Validators.required]
    });
  }

  ngOnInit() {
    // 恢复表单状态
    const savedState = localStorage.getItem('formState');
    if (savedState) {
      this.formGroup.setValue(JSON.parse(savedState));
    }
  }

  submitForm() {
    if (this.formGroup.valid) {
      // 保存表单状态并重定向
      localStorage.setItem('formState', JSON.stringify(this.formGroup.value));
      this.router.navigate(['/target']);
    } else {
      alert('Please fill all required fields.');
    }
  }
}