角反应形式程序设定器

Question

我有Angular Reactive Form验证。 为hiddenComposedField调用setter的正确方法是什么？

component.ts

ngOnInit() {
  this.myForm = this.formBuilder.group({
    'field1': ['', [Validators.required]],
    'field2': ['', [Validators.required]],
    'hiddenComposedField': [''],
  });

  this.myForm.get('field1').valueChanges.subscribe((val) => {
     this.setHiddenComposedField();
  });
  this.myForm.get('field2').valueChanges.subscribe((val) => {
     this.setHiddenComposedField();
  });
}

setHiddenComposedField() {
    let field1 = this.myForm.get('field1').value;
    let field2 = this.myForm.get('field2').value;

    // This doesn't work, but I want something like it:
    this.myForm.set('hiddenComposedField',field1 + ' ' + field2); // :(
}

component.html

<form [formGroup]="myForm">
  <input formControlName="field1">
  <input formControlName="field2">
  <!-- NB: hiddenComposedField is not exposed to the user; -->
  <!--     it is only on the submitted form model. -->
  <button type="submit">Submit</button>
</form>

Answer 1

这样的事情应该有效，这样你首先获得Control，然后设置它的值。

this.myForm.get('hiddenComposedField').setValue(field1 + ' ' + field2);

Answer 2

使用字符串插值的方式略有不同

setHIddenField(){
 const field1 = this.myForm.get('field1').value;
 const field2 = this.myForm.get('field2').value;
 const separator= ' --- ';
 let result = `${field1} ${separator} ${field2}`;
 this.myForm.get('hiddenComposedField').setValue(result);
}

这是StackBlitz链接。

Answer 3

这个问题的终极解决方案是订阅表单控件的valueState。

  import pandas as pd
   path = "data.csv"
  df = pd.read_csv(path)

import { combineLatest } from 'rxjs';

每当您更改表单中的值时，c 字段都会自动更新。

这是解决此类问题最合适的方法。