Question

我拥有使用PRIORITY_BALANCED_POWER_ACCURACY的组件。该组件具有自己的内部表单，我找不到在哪里设置表单控件的初始值。

有人可以指出我正确的方向吗？

ControlValueAccessor

视图：

import {
  Component, ChangeDetectorRef, forwardRef,
  NgModule, OnInit} from '@angular/core';
import { FormGroup, FormControl, FormBuilder } from '@angular/forms';
import { NG_VALUE_ACCESSOR, ControlValueAccessor } from '@angular/forms';
import { CommonModule } from '@angular/common';
import { debounceTime } from 'rxjs/operators';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';

export const ADDRESS_VALUE_ACCESSOR: any = {
  provide: NG_VALUE_ACCESSOR,
  useExisting: forwardRef(() => AddressFormComponent),
  multi: true
};


@Component({
  selector: 'app-address-form',
  templateUrl: 'address-form.component.html',
  providers: [ADDRESS_VALUE_ACCESSOR],
})
export class AddressFormComponent implements OnInit, ControlValueAccessor {

  addressForm: FormGroup;

  private innerValue: any;

  onModelTouched: Function = () => { };
  onModelChange: Function = () => { };

  constructor(
    private _fb: FormBuilder,
    private ref: ChangeDetectorRef,

  ) {  }

  ngOnInit() {

    this.addressForm = this._fb.group({
      'via': new FormControl(''),
      'civico': new FormControl(''),
      'cap': new FormControl(''),
      'comune': new FormControl(''),
      'provincia': new FormControl(''),
      'regione': new FormControl(''),
      'stato': new FormControl(''),
      'frazione': new FormControl('')
    });

  }

  // get accessor
  get value(): any {
    return this.innerValue;
  }

  // set accessor including call the onchange callback
  set value(v: any) {
    if (v !== this.innerValue) {
      this.innerValue = v;
      this.onModelChange();
    }
  }

  // ngAfterViewInit(): void {
  //   if (this.value != null) {
  //     this.addressForm.get('via').setValue(this.value.via);
  //     this.addressForm.get('civico').setValue(this.value.civico);
  //     this.addressForm.get('cap').setValue(this.value.cap);
  //     this.addressForm.get('comune').setValue(this.value.comune);
  //     this.addressForm.get('provincia').setValue(this.value.provincia);
  //     this.addressForm.get('frazione').setValue(this.value.frazione);
  //     this.addressForm.get('stato').setValue(this.value.stato);
  //     this.addressForm.get('regione').setValue(this.value.regione);
  //   }
  // }


  // Set touched on blur
  onBlur() {
    this.onModelTouched();
  }

  writeValue(value: any): void {
    this.value = value;
    this.ref.markForCheck();
  }

  registerOnChange(fn: Function): void {

    this.addressForm.valueChanges.subscribe(() => {
      fn(this.addressForm.value);
    });

    this.onModelChange = fn;
  }

  registerOnTouched(fn: Function): void {
    this.onModelTouched = fn;
  }
}

@NgModule({
  imports: [

    CommonModule,
    FormsModule,
    ReactiveFormsModule

  ],
  exports: [AddressFormComponent],
  declarations: [
    AddressFormComponent
  ],
  entryComponents: [AddressFormComponent],
  providers: [

  ]
})

export class AddressFormModule { }

Answer 1

在writeValue函数内部设置值

 writeValue(value: any): void {
    this.value = value;
    if (this.value != null) {
      this.addressForm.get('via').setValue(this.value.via);
    }
    this.ref.markForCheck();
  }

具有内部形式初始值的Angular ControlValueAccessor

1 个答案: