Question

当我想在每次加载时将以前保存的值从本地存储器归因于此表单时，我会遇到与模型驱动表单相关的内容（内置于Ionic 2中）。

我设法使用Ionic的存储服务保存它，但是我没有将这些保存的数据归因于表单。我收到以下错误：

TypeError：设置只有getter的属性

这是我的代码，到目前为止：

import { Component } from '@angular/core';
import { Validators, FormBuilder, FormGroup } from '@angular/forms';
import { NavController, NavParams } from 'ionic-angular';
import { Storage } from '@ionic/storage';

@Component({
  selector: 'page-survey',
  templateUrl: 'survey.html',
  providers: [Storage]
})

export class Survey {
  form: FormGroup;
  networkStatus: boolean = true;

  constructor(public navCtrl: NavController, public navParams: NavParams,
              public formBuilder: FormBuilder, private storage: Storage) {

    // localstorage 
    this.storage = storage;

    this.form = formBuilder.group({
      "isPropertyOwner": ["", Validators.required],
      "familyMembers": ["", Validators.compose([Validators.required, Validators.minLength(0)])],
      "ownsProperty": ["", Validators.required],
      "pragueIdentify": ["", Validators.required],
      "pesticidesUsage": ["", Validators.required],
      "propertyLevel": ["", Validators.required]
    });

    /* Check if form has been changed */
   this.form.valueChanges.subscribe(data => 
      this.storage.set('survey', data)
    );
  }

  ngAfterViewInit() {
    // checking if there's something saved, then...
    if(this.storage.get('survey')) {
      this.storage.get('survey').then((data) => {
        console.log('This is ', data);
        this.form.value = data;
      });
    }
  }

  onSubmit(form) {
    console.log(form);
    this.storage.clear().then(() => {
      console.log('Keys have been cleared');
    });

  }
}

如何将保存的值归因于此表单？

Answer 1

public static void SelectOptions(String value) { driver.findElement(By.xpath("//input[@value='"+value+"']")).click(); }的属性FormGroup是一个只读属性，这意味着您无法直接编辑它。您需要使用value函数获取每个get()，然后使用FormControl函数更改其值。无论如何，而不是：

setValue()

你需要使用它：

this.form.value = data;

Answer 2

我认为您必须在从constructor删除以下两行后检查，因为您已将private storage: Storage声明为constructor参数。

// localstorage 
this.storage = storage;

离子2 - 设定模型驱动形式的值

2 个答案: