Angular FormGroup：如何将FormControlname移动到NG-Template外部FormGroupName？

Question

此代码正在工作：

<form id="list" [formGroup]="Form">
  <ion-list lines="none" class="list">
    <ion-item-sliding formArrayName="things" *ngFor="let item of formArray.controls; index as index"> 
        <ion-item [formGroupName]="index">

          <ng-container [ngTemplateOutlet]="thingText" [ngTemplateOutletContext]="{item:item, index:index}"></ng-container>

          <ng-template #thingText let-item="item" let-index="index">
            <ion-textarea id="thing-text" formControlName="content" auto-grow 
              value="{{ item.value.content }}" 
              (click)="activateEditing(index)"
              (ionBlur)="leaveTheField(index)" 
              (keypress)="detectChange(index)"
              (ionFocus)="changeScroll(index)" #activeThings>
            </ion-textarea>
          </ng-template>

        </ion-item>
    </ion-item-sliding>
  </ion-list>
</form>

但是我想将ng-template移出表格之外。但是，当我这样做时，我会得到错误：必须与父formgroup指令一起使用formControlname。。

然后，我试图将FormGroup传递到NG-Template：

<ng-container [ngTemplateOutlet]="thoughtText" [ngTemplateOutletContext]="{formGroup: Form, item:item, index:index}"></ng-container>

(...)

<ng-template #thoughtText let-item="item" let-index="index" let-formGroup="formGroup">
  <div [formGroup] = "formGroup">
    <ion-textarea id="thing-text" formControlName="content" auto-grow
                  value="{{ item.value.content }}"
                  (click)="activateEditing(index)"
                  (ionBlur)="leaveTheField(index)"
                  (keypress)="detectChange(index)"
                  (ionFocus)="changeScroll(index)" class="active-text form-control" #activeThing>
    </ion-textarea>
  </div>
</ng-template>

但它不起作用。我得到了“ eRROR：找不到名称的控制：'content'“

我该怎么做才能将ng-template移出表单之外？

Answer 1

一种方法是将form controlname传递到ng-template并使用[formControl]。见下文。

<ng-container [ngTemplateOutlet]="thoughtText" 
              [ngTemplateOutletContext]="{formGroup: Form, item:item, index:index, formControlName: 'content'}"></ng-container>

(...)

<ng-template #thoughtText let-item="item" let-index="index" let-formGroup="formGroup" let-formControlName="formControlName">
  <div [formGroup] = "formGroup">
    <ion-textarea id="thing-text" [formControl]="formGroup.get(formControlName)" auto-grow
                  value="{{ item.value.content }}"
                  (click)="activateEditing(index)"
                  (ionBlur)="leaveTheField(index)"
                  (keypress)="detectChange(index)"
                  (ionFocus)="changeScroll(index)" class="active-text form-control" #activeThing>
    </ion-textarea>
  </div>
</ng-template>