角度-如何获得在下拉菜单中选择的值？

Question

Goal : I want to be able to have the user click a value in a dropdown, that will change the address of the site they are on, based on the selection.

Problem : I was able to get it to change the address, but it would do it no matter what selection they made. I want it to go to a different address for each selection.

So if they choose "English" I want it to go to site.com/en. And if they choose Spanish I want it to go to site.com/es

What I tried :

I tried the solution, and many variations of it from: How to get Id of selected value in Mat-Select Option in Angular 5 I also looked through Angular material documentation but it is a bit sparse on everything needed for this topic.

Why is the specific selection not being recognized?

HTML :

<mat-form-field class="right">
      <mat-select>
          <mat-option *ngFor="let language of languages" [value]="language.value" (selectionChange)="doSomething($event.value)">
              {{language.viewValue}}
          </mat-option>
    </mat-select>
</mat-form-field>

TypeScript :

doSomething(event) {
   //if value selected is spanish
   if(event.value == "es")
      this.routerService.navigate(['es/']);
}

Answer 1

Try moving your selectionChanged to your select, not the option:

<mat-form-field class="right">
      <mat-select (selectionChange)="doSomething($event)">
          <mat-option *ngFor="let language of languages" [value]="language.value" >
              {{language.viewValue}}
          </mat-option>
    </mat-select>
</mat-form-field>

https://material.angular.io/components/select/api#MatSelect

Answer 2

Or you can use ngModel to access value directly in your function

<mat-form-field class="fullwidth" required>
  <mat-label>Select</mat-label>
  <mat-select [(ngModel)]="selectedItem" (ngModelChange)="onSelectChange(selectedItem)">
    <mat-option *ngFor="let obj of testArray" [value]="obj.value">
      {{obj.name}}
    </mat-option>
  </mat-select>
</mat-form-field>

On your .ts file

onSelectChange(value) {
//if value selected is spanish
  if(value == "es")
    this.routerService.navigate(['es/']);
}