@ViewChild 返回未定义 - Angular 2

Question

I'm trying to use @ViewChild to get the DOM element that I need. I have the following component that describes my problem:

import {Component, ViewChild, ElementRef, OnInit, Input} from "@angular/core";


@Component({
  selector: 'some-comp',
  template: `

  <input
    #myInputOut
    type="text"
    class="google-place-input"
    placeholder="Type to search..">

   <span class="row form-group">
     <required-input
       class="col-12 has-danger"
       [label]="'somel:'"
       [controlName]="'somel'"
       [form]="group"
      </required-input>
    </span>

 <div class="row form-group2 required">
    <label class=" col-3 control-label" for="street">label:</label>
    <input #myInputIn class="col-7" id="someid" placeholder="Type to search.." /></div>
`
})
export class someClass implements OnInit{

  @ViewChild('myInputOut') myInputOut: ElementRef;
  @ViewChild('myInputIn') myInputIn: ElementRef;


  private element: HTMLInputElement;
  private element2: HTMLInputElement;

    constructor(  private databaseService : DatabaseService,
               private router : Router){

  }


  ngOnInit(){
    this.element = this.myInputOut.nativeElement;
    this.element2 = this.myInputIn.nativeElement;
  }
}

For some reason myInputOut returns properly but myInputIn returns undefined. How can I solve this?

Answer 1

Looks like you are commenting the input or at least started to

 <!--  <div class="row form-group2 required">
    <label class=" col-3 control-label" for="street">label:</label>
    <input #myInputIn class="col-7" id="someid" placeholder="Type to search.." />

"<!--" shouldn't be there

Answer 2

You will be able to access ViewChild queries only inside ngAfterViewInit(). It's not available in ngOnInit() hence you are getting undefined.

Answer 3

There are some errors in the code, kindly fix it and try again.

<required-input
   class="col-12 has-danger"
   [label]="'somel:'"
   [controlName]="'somel'"
   [form]="group"

there should be a closing tag --> [form]="group" >

<!--<div class="row form-group2 required">

Remove " <!-- " before the <div class="row form-group2 required"> and close it properly with </div>

Finally, declare input type type="text"

<input #myInputIn type="text" class="col-7" id="someid" placeholder="Type to search.." />