angular - Angular 4 中的动态绑定(bind)下拉选项

Question

我使用下面的代码绑定(bind)重复下拉并选择存储在数据库中的下拉值

<div class="form-group row" *ngFor="let option of roles let x = index">
    <div class="col-8">
        <select [disabled]="adminstratorStatus=='true'" class="form-control custom-select col-12" id="company_info_management" required
        [(ngModel)]="option.module_defaultselection" name="company_info_management"
        #company_info_management="ngModel" (ngModelChange)="onSelect($event,x)">
            <option value=''>--select company--</option>
            <option *ngFor="let myRole of option.module_role;" value= {{myRole.module_role}}>
            <!--[ngValue]="myRole.module_role"-->
                {{myRole.module_role_description | translate }}
            </option>
        </select>
    </div>
</div>

使用 ngModel 选择下拉值是行不通的

module_defaultselection 有适当的值，可以在下拉选项中找到。

Answer 1

在选择下拉菜单中使用 [ngModelOptions]="{standalone: true}"引用下面的代码

<div class="form-group row" *ngFor="let option of roles let x = index">
      <div class="col-8">
          <select [disabled]="adminstratorStatus=='true'" class="form-control custom-select col-12" id="company_info_management" required
                                                    [(ngModel)]="roles[x].module_defaultselection" name="company_info_management"
                                                    #company_info_management="ngModel"   [ngModelOptions]="{standalone: true}">
                                                <option value="">--select company--</option>
                                                <option *ngFor="let myRole of option.module_role;" value="{{myRole.module_role}}"> {{myRole.module_role_description | translate }} </option>
                                            </select>
                                        </div>
                                    </div>