Angular 在选择框中保存id onchange()选项的值
我需要帮助我正在尝试创建一个依赖选择选项,问题是我需要将第一个选择的id值(career.id)保存在component.ts中的变量中Angular 在选择框中保存id onchange()选项的值,angular,angular-material,angular8,Angular,Angular Material,Angular8,我需要帮助我正在尝试创建一个依赖选择选项,问题是我需要将第一个选择的id值(career.id)保存在component.ts中的变量中 getAsignaturasDocente () { const parameters = '? user_id =' + this.user.id + '& carrera_id =' + *** variable_that I need *** this.spinner.sho
getAsignaturasDocente () {
const parameters =
'? user_id =' + this.user.id
+ '& carrera_id =' + *** variable_that I need ***
this.spinner.show();
this.service.get('teachers/subjects' + parameters) .subscribe (
response => {
this.asignaturasdocente = response['asignaturasdocente '];
this.spinner.hide ();
},
error => {
this.spinner.hide ();
});
}
getAsignaturasDocente (carreraId) {
const parameters =
'? user_id =' + this.user.id
+ '& carreraId =' + *** variable_that I need ***
this.spinner.show();
this.service.get('teachers/subjects' + parameters) .subscribe (
response => {
this.asignaturasdocente = response['asignaturasdocente '];
this.spinner.hide ();
},
error => {
this.spinner.hide ();
});
}
HTML
在select标记上执行ngModelChange(),如下所示:
组件技术
getAsignaturasDocente () {
const parameters =
'? user_id =' + this.user.id
+ '& carrera_id =' + *** variable_that I need ***
this.spinner.show();
this.service.get('teachers/subjects' + parameters) .subscribe (
response => {
this.asignaturasdocente = response['asignaturasdocente '];
this.spinner.hide ();
},
error => {
this.spinner.hide ();
});
}
getAsignaturasDocente (carreraId) {
const parameters =
'? user_id =' + this.user.id
+ '& carreraId =' + *** variable_that I need ***
this.spinner.show();
this.service.get('teachers/subjects' + parameters) .subscribe (
response => {
this.asignaturasdocente = response['asignaturasdocente '];
this.spinner.hide ();
},
error => {
this.spinner.hide ();
});
}
请看代码,我将您的carrera\u id更改为carreraId,但您可以使用carrera\u id
HTML:
<td>
<select [disabled]="flagAsignaturasCupo"
[(ngModel)]="carrera.id" class="form-control"
(ngModelChange)="getAsignaturasDocente(carrera.id)"
id="carrera" name="carrera" required>
<option value="0" selected>SELECCIONE UNA CARRERA</option>
<option value="{{carrera.id}}" *ngFor="let carrera of carrerasdocente"
class="small">{{ carrera.descripcion }}</option>
</select>
塞莱奇奥尼卡雷拉酒店
{{carrera.Description}}
我之所以使用ngModelChange(),是因为您使用ngModel绑定数据,这样您就可以使用ngModelChange()。我是否正确地认为,当选择了一个新项目时,您想知道最后选择的项目是什么?如果是这样的话,您是否考虑过在每次更改选择时保存该选择?因此,当出现新选择时,您会使用上一个加上新的?