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Angular2，ngModel和Forms：列表无法正确显示

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我正确显示：它's always the last item of the array which is displayed. If i use mustache syntax to display the array outside inputs, it'确定 . 如果我删除表单和控件，它没关系 . 你可以在这里测试一下：plunker . 这是代码：

@Component({
  selector: "my-app",
  providers: [],
  template: "
    <div>
      <form [formGroup]="personControl">
        <div *ngFor="let person of persons; let i = index">
          index : {{i}}

          label : {{person.label}}

          value : {{person.value}}

          <input type="text" 
                 maxlength="30" 
                 [id]="'label-'+person.id" 
                 [(ngModel)]="person.label"
                 formControlName="personLabel"/>
          <input type="text" 
                 maxlength="30" 
                 [id]="'value-'+person.id" 
                 [(ngModel)]="person.value"
                 formControlName="personValue"/>
        </div>
      </form>
    </div>
  ",
  directives: [REACTIVE_FORM_DIRECTIVES]
})
export class App {
  private personControl: FormGroup;
  private persons : Person[];
  constructor(private _formBuilder: FormBuilder) {
    this.persons = PERSONS;
    this.personControl = this._formBuilder.group({
      personLabel : new FormControl("", 
        [
          Validators.required
        ]),
        personValue : new FormControl("", 
        [
          Validators.required
        ])
    });

  }
}

export class Person {
  id: number;
  label: string;
  value : number;
}

const PERSONS: Person[] = [
  { id: 1, label: "Person One", value : 10 },
  { id: 2, label: "Person Two", value : 20 },
  { id: 3, label: "Person Three", value : 30 }
];

我试着看看formArrayName，但似乎它不适用于几个输入，你不能使用ngModel . 有人有想法吗？

我使用角度2.0.0-rc.4并形成0.2.0

angular angular2-forms

2 回答

  • 1

    formControlName="personLabel" 和 formControlName="personValue" 必须是唯一的 . 它们采用最后一个标签和值，因为 persons 中的最后一个对象覆盖了之前的对象 .

    您必须为每个定义唯一的 FormControl ：

    this.personControl = new FormGroup({
  personLabel0 : new FormControl('', 
    [
      Validators.required
    ]),
    personValue0 : new FormControl('', 
    [
      Validators.required
    ]),
    personLabel1 : new FormControl('', 
    [
      Validators.required
    ]),
    personValue1 : new FormControl('', 
    [
      Validators.required
    ]),
    personLabel2 : new FormControl('', 
    [
      Validators.required
    ]),
    personValue2 : new FormControl('', 
    [
      Validators.required
    ])
});

    你可以用一个函数动态调整 formControlName ：

    public getName(word, i) {
    return "person" + word + i;
}

    您可以从模板中调用该函数：

    <div *ngFor="let p of persons; let i = index">
      index : {{i}}
    
      label : {{p.label}}
    
      value : {{p.value}}
    
      <input type="text" 
             maxlength="30" 
             [id]="'label-'+p.id" 
             [(ngModel)]="p.label"
             formControlName="{{getName('Label', i)}}"
             placeholder="{{p.id}}"/>
      <input type="text" 
             maxlength="30" 
             [id]="'value-'+p.id" 
             [(ngModel)]="p.value"
             formControlName="{{getName('Value', i)}}"/>
    </div>

    我还没有 FormGroup 的经验，所以我不知道是否有办法动态地将新 FormControls 推入 FormGroup （ personControl ）对象，不断调整名称 . 如果没有，将建议反对"model driven"表格 .

    Plunker：https://plnkr.co/edit/ERWA6GKX9VYADouPb6Z2?p=preview

    回复于
  • 0

    好的，谢谢你的回复 . 我不明白formControlName必须是唯一的 .

    我在formControlName上创建了另一个带有修正的插件：https://plnkr.co/edit/chiCdN5A7Vb4MCrAYaSE?p=info

    这是代码：

    @Component({
  selector: 'my-app',
  providers: [],
  template: `
    <div>
      <form [formGroup]="personControl">
        <div *ngFor="let person of persons; let i = index">
          index : {{i}}
    
          label : {{person.label}}
    
          value : {{person.value}}
    
          <input type="text" 
                 maxlength="30" 
                 [id]="'label-'+person.id" 
                 [(ngModel)]="person.label"
                 [formControlName]="'personLabel'+person.id" />
          <input type="text" 
                 maxlength="30" 
                 [id]="'value-'+person.id" 
                 [(ngModel)]="person.value"
                 [formControlName]="'personValue'+person.id" />
        </div>
      </form>
    </div>
  `,
  directives: [REACTIVE_FORM_DIRECTIVES]
})
export class App {
  private personControl: FormGroup;
  private persons : Person[];
  constructor(private _formBuilder: FormBuilder) {
    this.persons = PERSONS;
    let ctrls = {};

    this.persons.forEach(((person: Person) => {
      ctrls[`personLabel${person.id}`] = new FormControl('', 
        [
          Validators.required
        ]);
        ctrls[`personValue${person.id}`] = new FormControl('', 
        [
          Validators.required
        ]);
    }).bind(this));
    this.personControl = this._formBuilder.group(ctrls);

  }
}

export class Person {
  id: number;
  label: string;
  value : number;
}

const PERSONS: Person[] = [
  { id: 1, label: 'Person One', value : 10 },
  { id: 2, label: 'Person Two', value : 20 },
  { id: 3, label: 'Person Three', value : 30 }
];
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