angular-forms

何时使用哪种表单

使用场景	建议
使用信号的新应用	信号表单（实验性）
生产环境应用	响应式表单
简单表单	模板驱动

---

信号表单（v21+，实验性）

import { form, FormField, required, email } from '@angular/forms/signals';

@Component({
  imports: [FormField],
  template: `
    <form>
      <input [formField]="emailField" type="email" />
      <input [formField]="passwordField" type="password" />
      <button (click)="submit()">Login</button>
    </form>
  `
})
export class LoginComponent {
  readonly loginForm = form({
    email: ['', [required, email]],
    password: ['', required]
  });
  
  readonly emailField = this.loginForm.controls.email;
  readonly passwordField = this.loginForm.controls.password;
  
  submit() {
    if (this.loginForm.valid()) {
      const values = this.loginForm.value();
    }
  }
}

信号表单的优势

• 自动双向绑定
• 类型安全的字段访问
• 基于 Schema 的验证
• 基于信号构建

---

响应式表单（生产环境）

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

@Component({
  imports: [ReactiveFormsModule],
  template: `
    <form [formGroup]="form" (ngSubmit)="submit()">
      <input formControlName="email" type="email" />
      <input formControlName="password" type="password" />
      <button type="submit" [disabled]="form.invalid">Login</button>
    </form>
  `
})
export class LoginComponent {
  private readonly fb = inject(FormBuilder);

  form = this.fb.nonNullable.group({
    email: ['', [Validators.required, Validators.email]],
    password: ['', [Validators.required, Validators.minLength(8)]],
  });
  
  submit() {
    if (this.form.valid) {
      const { email, password } = this.form.getRawValue();
    }
  }
}

要点

• 始终使用 fb.nonNullable.group() 确保类型安全
• 使用 getRawValue() 获取类型化的值
• 响应式表单是同步的（更易于测试）

---

嵌套表单和 FormArray

form = this.fb.nonNullable.group({
  name: [''],
  address: this.fb.group({
    street: [''],
    city: [''],
  }),
  phones: this.fb.array([this.fb.control('')]),
});

get phones() {
  return this.form.get('phones') as FormArray;
}

addPhone() {
  this.phones.push(this.fb.control(''));
}

---

资源

• https://angular.dev/guide/forms/signals/overview
• https://angular.dev/guide/forms/reactive-forms