时间戳

首页 > 解决方案 > ngModel 不显示值

angular - ngModel 不显示值

问题描述

在 Html 中，它没有显示ngModel已分配 selectedValueModel 的位置。
也试过了[ngValue]，它给undefined了我的ngModelChange功能。

提前致谢。

foods: Food[] = [
    {value: 'steak-0', viewValue: 'Steak'},
    {value: 'pizza-1', viewValue: 'Pizza'},
    {value: 'tacos-2', viewValue: 'Tacos'}
  ];
selectedValueModel = {value: 'steak-0', viewValue: 'Steak'};
@Output() selectedValueChange = new EventEmitter()

changing(newValue: any) {
    this.selectedValueModel = newValue
    this.selectedValueChange.emit(newValue)
  }

我的 HTML：

<mat-form-field>
    <mat-select placeholder="Favorite food" 
   [(ngModel)]="selectedValueModel.value" 
   (ngModelChange)="changing($event)" name="food">
      <mat-option *ngFor="let food of foods" [value]="food.value">
        {{food.viewValue}}
      </mat-option>
    </mat-select>
  </mat-form-field>

标签： angulartypescriptangular-materialangular2-template

解决方案

改变 ：

<mat-form-field>
<mat-select placeholder="Favorite food" 
[(ngModel)]="selectedValueModel.value"
(ngModelChange)="changing($event)" name="food">
  <mat-option *ngFor="let food of foods" [value]="food.value">
    {{food.viewValue}}
  </mat-option>
</mat-select>

至：

<mat-form-field>
<mat-select placeholder="Favorite food" 
[(ngModel)]="selectedValueModel"
(ngModelChange)="changing($event)" name="food">
  <mat-option *ngFor="let food of foods" [value]="food.value">
    {{food.viewValue}}
  </mat-option>
</mat-select>

推荐阅读