// 封裝獲取modelList
    get modelList() {
        return this.formGroup.get('modelList') as FormArray
    }
    constructor(private fb: FormBuilder) {}
    ngOnInit() {
        // 一開始初始化arr為空數(shù)組
        this.formGroup = this.fb.group({
            // 內(nèi)部嵌套FormControl、FormArray、FormGroup
            modelList: this.fb.array([])
        })
    }
    // 模態(tài)框構造內(nèi)部的表單
    function newModel() {
        return this.fb.group({
            modelName: [''],
            // 可以繼續(xù)嵌套下去，根據(jù)業(yè)務需求
        })
    }
    // 省略模態(tài)框部分代碼
    // 傳遞到模態(tài)框的FormArray
    selectedType: FormArray

<form [FormGroup]="formGroup">
    <div FormArrayName="modelList">
        <ng-container *nfFor="let item of modelList.controls;let i = index" [FormGroupName]="i">
            <nz-input-group
                [nzSuffix]="suffixIconSearch"
              >
                <input type="text" nz-input formControlName="modelName"/>
              </nz-input-group>
              <ng-template #suffixIconSearch>
                <span
                  nz-icon
                  nzType="edit"
                  class="hover"
                  (click)="showModal(i)"
                ></span>
              </ng-template>
        </ng-container>
    </div>
</form>
<nz-modal
  [(nzVisible)]="isVisible"
  nzTitle="Model"
  [nzFooter]="modalFooter"
  (nzOnCancel)="handleCancel()"
  (nzOnOk)="handleOk()"
>
  <ng-container *nzModalContent>
    <form nz-form [formGroup]="selectedType">
      <nz-form-item>
        <nz-form-label nzRequired>Model Test</nz-form-label>
        <nz-form-control>
          <input
            type="text"
            nz-input
            placeholder="請輸入ModelName"
            formControlName="modelName"
          />
        </nz-form-control>
      </nz-form-item>
      <nz-form-item>
        <nz-form-control>
          <product-config></product-config>
        </nz-form-control>
      </nz-form-item>
    </form>
  </ng-container>
  <ng-template #modalFooter>
    <button *ngIf="!isNewModel" nzDanger nz-button nzType="default" (click)="handleDelete()">刪除</button>
    <button *ngIf="isNewModel" nz-button nzType="default" (click)="handleCancel()">取消</button>
    <button nz-button nzType="primary" (click)="handleOk()">保存</button>
  </ng-template>
</nz-modal>

this.modelList.removeAt(this.modelIndex)
this.modelList.insert(this.modelIndex, this.selectedType)

newModelType(): FormGroup {
    return this.fb.group({
      modelName: ['', Validators.required],
      configList: this.fb.array([]),
    });
  }
// ...省略
// 模態(tài)框顯示
show() {
    this.isVisible = true
    this.selectedType = this.newModelType();
}
// 保存
save() {
    this.isVisible = false
    // 原頁面FormArray
    this.modelList.push(this.selectedType);
}

this . mode llist. removeAt ( this . mode lIndex )
this . modell ist. insert(this . modelIndex, this . se lectedType)

      this.selectedType = this.newModelType();
      const old = this.modelList.at(index);
      this.selectedType.setValue({
        'modelName': old.get('modelName').value
    })