如何在angular2中对活动表单执行CRUD操作和正确使用接口？

Question

我正在创建一个反应式表单数组来实现CRUD操作。经过长时间的谷歌搜索，我发现有几种方法可以实现这一点。 我的怀疑是：

1. 如何使用货币界面制作数据模型 形式？
2. 如何在按钮单击（addItem（））上添加项目数组？

3. 提交后，是否可以将模型导出为JSON？

   Github source code

currency.interface.ts

export interface Currency {
  name: string;
  date: string;
  address: string;
  remarks: string;
  serialNumber: number;
  idNumber: number;
  phoneNumber: number;
  mobileNumber: number;
  nationality: string;
  totalCost: number;
  tax: number;
  taxTotal: number;
  grandTotal: number;
  items: Item[];
}

export interface Item {
  currencyName: string;
  currencyType: string;
  currencyValue:string;
  total: number;
  presentRate:number;
}

currency.component.ts

ngOnInit() {
    this.currencyType = ['CN & Coins']
    this.myForm = this.fb.group({
          name: ['', [Validators.required, Validators.minLength(2)]],
          date: ['', [Validators.required, Validators.minLength(2)]],
          address: ['', [Validators.required, Validators.minLength(2)]],
          remarks: ['', [Validators.required, Validators.minLength(2)]],
          serialNumber: ['', [Validators.required, Validators.minLength(1)]],
          idNumber: ['', [Validators.required, Validators.minLength(2)]],
          phoneNumber: ['', [Validators.required, Validators.minLength(2)]],
          mobileNumber: ['', [Validators.required, Validators.minLength(2)]],
          nationality: [''],
          tax: ['', [Validators.minLength(2)]],
          totalCost: [{ value: '', disabled: true }, [Validators.minLength(2)]],
          taxAmount: [{ value: '', disabled: true }, [Validators.minLength(2)]],
          grandTotal: [{ value: '', disabled: true }, [Validators.minLength(2)]],
          items: this.fb.array([
              this.initItem(),
          ])
      });
    }
    initItem() {
      return this.fb.group({
          currency: [''],
          currencyName: [''],
          currencyType: [''],
          amount: [],
          presentRate:[''],
          total:[{ value: '', disabled: true }, [Validators.minLength(2)]]
      });
  }

currency.component.html

<div class="flex-item" fxFlex="50%">
        <md-card class="app-input-section" style="height: relative" >
          <md2-datepicker formControlName="date"></md2-datepicker>
          <div formArrayName="items">
             <div let i=index>
                 <div [formGroupName]="i">
                   <md2-autocomplete [items]="currency"
                             item-text="currency"
                             (change)="handleChange($event, i)"
                             placeholder="Currency purchased"
                             formControlName="currency"
                             >
                   </md2-autocomplete>

                   <md-select placeholder="Currency type" formControlName="currencyType">
                     <md-option *ngFor="let type of currencyType" [value]="type" >
                       {{type}}
                     </md-option>
                   </md-select>
                   <md-input-container >
                     <input mdInput placeholder="Amount" formControlName="amount">
                   </md-input-container>
                   <md-input-container >
                     <input mdInput placeholder="Present rate" [value]="presentRate" formControlName="presentRate"  >
                   </md-input-container>
                   <md-input-container >
                     <input mdInput placeholder="Rupee Equivalent" value={{getRupee()}} formControlName="total" >
                   </md-input-container>
                 </div>
                 <div class="flex-item" fxFlex >
                   <button md-raised-button color="primary" type="submit" >Save</button >
                   <button md-raised-button color="primary" (click)="addItem()">Add</button>
                   <button md-raised-button color="warn">Remove selected currency</button>
                   <button md-raised-button >Edit</button>
                 </div>
             </div>
          </div>
        </md-card>
      </div>