How to get Id of selected value in Mat-Select Option in Angular 5

问题

How to get the id of selected option value in mat-select angular 5. Get only value of selected option in onchangeevent. but how can get id of selected option value.

 client.component.html
<mat-form-field>
    <mat-select placeholder="Client*" #clientValue  (change)="changeClient($event)">
    <mat-option  *ngFor="let client of clientDetails"   [value]="client.clientName">
      {{client.clientName |  json}}
    </mat-option>
  </mat-select>
</mat-form-field>

client.component.ts file
export class Client{
     changeClient(event){
     console.log(event);
 }
}

回答1:

For that you need to :

Change (change)="changeClient($event)" to (change)="changeClient($event.value)"

and from [value]="client.clientName" to [value]="client.id"

<mat-form-field>
    <mat-select placeholder="Client*" #clientValue  (change)="changeClient($event.value)">
    <mat-option  *ngFor="let client of clientDetails"   [value]="client.id">
      {{client.clientName}}
    </mat-option>
  </mat-select>
</mat-form-field>

WORKING DEMO

回答2:

The question is specific to Angular 5 but for others coming here with a newer version of Angular, the (change) event won't work for mat-select.

In Angular 6 the (change) event has been changed to (selectionChange).

So it would be :

<mat-form-field>
    <mat-select placeholder="Client*" #clientValue  (selectionChange)="changeClient($event.value)">
    <mat-option  *ngFor="let client of clientDetails" [value]="client.id">
      {{client.clientName}}
    </mat-option>
  </mat-select>
</mat-form-field>

And in the component:

changeClient(value) {
    console.log(value);
}

From this answer and the documentation.

回答3:

You can also subscribe to the values change of the mat-select by using the ViewChild decorator and ngAfterViewInit which is less 'html-intrusive'.

Here is an example :

[HTML]

<mat-form-field [floatLabel]="auto">
    <mat-label>Type</mat-label>
        <mat-select #matSelect required> //the #matSelect is important here
            <mat-option *ngFor="let type of types" [value]="type.value">
                {{type.viewValue}}
            </mat-option>
    </mat-select>
</mat-form-field>

[TS]

 import { Component, ViewChild, AfterViewInit } from '@angular/core';
 import { MatSelect } from '@angular/material';

 @Component({
        selector: 'app-export-security-pack-material',
        templateUrl: './export-security-pack-material.component.html',
        styleUrls: ['./export-security-pack-material.component.scss']
 })

 export class ExportSecurityPackMaterialComponent implements AfterViewInit {

    constructor() {}

    types: Object[] = [
        { value: 'example-value-0', viewValue: 'ExampleViewValue0' 
        },
        { value: 'example-value-1', viewValue: 'ExampleViewValue1' }
    ];

    @ViewChild('matSelect') matSelect: MatSelect;
       //Reference Variable //variable Name //Type

    ngAfterViewInit() {
        this.matSelect.valueChange.subscribe(value => {
            console.log(value);
        });
    }
 }

With this your value should be logged in the development console Ctrl+Shift+I or F12 everytime you change your selector value.

or you can literally just do this if you dont need onchange :

[HTML]

<mat-form-field [floatLabel]="auto">
    <mat-label>Type</mat-label>
        <mat-select [(value)]="matSelectValue" required> <---
            <mat-option *ngFor="let type of types" [value]="type.value">
                {{type.viewValue}}
            </mat-option>
    </mat-select>
</mat-form-field>

来源：https://stackoverflow.com/questions/48705555/how-to-get-id-of-selected-value-in-mat-select-option-in-angular-5

标签

angular

angular-material-5