angular – 如何在ngFor(嵌套formArray)中访问ngFor中的formControlName？

2023年6月2日 312次阅读

我是Angular 2的初学者.我正在尝试创建一个具有动态表单的表,创建表并且值也绑定但是我无法访问formControlName中的值,尝试下面的代码但它不起作用.

有人可以帮助我在下面的代码我做错了

HTML

<tbody formArrayName="timetable">
     <tr *ngFor="let child of timetableForm.controls.timetable.controls; let i = index;" [formGroupName]="i">
        <td *ngFor="let period of child.controls.periods.controls;let j = index;" [formGroupName]="j">
            {{period.controls.day.value}} <!-- bind is working fine -->
            <input type="text" [formControlName]="day">  <!-- error -->                               
        </td>
     </tr>
</tbody>

TS

ngOnInit(){
this.tableForm = this.formBuilder.group({
      timetable: this.formBuilder.array([
             this.formBuilder.group({
                    periods: this.formBuilder.array([
                        this.formBuilder.group({
                            subject_id:10,
                            timing_id:11,
                            day:'Monday'
                        }),
                        this.formBuilder.group({
                            subject_id:10,
                            timing_id:11,
                            day:'Tuesday'
                        }),
                        this.formBuilder.group({
                            subject_id:10,
                            timing_id:11,
                            day:'Wednesday'
                        }),
                        this.formBuilder.group({
                            subject_id:10,
                            timing_id:11,
                            day:'Thursday'
                        }),
                        this.formBuilder.group({
                            subject_id:10,
                            timing_id:11,
                            day:'Friday'
                        })
                    ])
                }),
                this.formBuilder.group({
                    periods: this.formBuilder.array([
                        this.formBuilder.group({
                            subject_id:10,
                            timing_id:11,
                            day:'Monday'
                        }),
                        this.formBuilder.group({
                            subject_id:10,
                            timing_id:11,
                            day:'Tuesday'
                        }),
                        this.formBuilder.group({
                            subject_id:10,
                            timing_id:11,
                            day:'Wednesday'
                        }),
                        this.formBuilder.group({
                            subject_id:10,
                            timing_id:11,
                            name:'Thursday'
                        })
                    ])
                })
            ])
         });

提前致谢.

最佳答案 我注意到的第一件事

this.formBuilder.group({
      subject_id:10,
      timing_id:11,
      name:'Thursday'
      ^^^^
 it should be day
})

其次,为什么在组件中创建tableForm时在模板中使用timetableForm？

第三,你应该使用formControlName =“day”而不是注释中提到的[formControlName] =“day”.

最后,您忘记将您的子数组包装在formArrayName =“periods”中.为此,您可以使用ng-container,如下所示：

<table [formGroup]="tableForm">
    <tbody formArrayName="timetable">
        <tr *ngFor="let child of tableForm.controls.timetable.controls; let i = index;" [formGroupName]="i">
            <ng-container formArrayName="periods">
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                       add this
                <td *ngFor="let period of child.controls.periods.controls;let j = index;" [formGroupName]="j">
                    {{period.controls.day.value}}
                    <input type="text" formControlName="day">
                </td>
            </ng-container>
        </tr>
    </tbody>
</table>

Ng-run Example

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