mat-select returns 在 SelectionChange() 上未定义
mat-select returns undefined on SelectionChange()
我在 (selectionChange) 事件上有 mat-select 我收到未定义的值 $event.value
。它 returns 第一个 mat-option.mat 选项的正确值 'All' 它给出了 undefined
<mat-form-field>
<mat-select [(value)]="regionOption" (selectionChange)="regionSelectionChange($event)"
placeholder="Region">
<mat-option *ngFor="let region of regions" [value]="region.location_name">{{region.location_name}}</mat-option>
<mat-option [value]="All" >All</mat-option>
</mat-select>
</mat-form-field>
//ts
regionSelectionChange(regionName)
{
console.log(regionName);
}
将您的值绑定从 [value] 更改为值
<mat-option value="All">All</mat-option>
我会选择这个:
TS代码:
export class FormFieldOverviewExample {
regions: any[]= [{'location_name':"Pune"},{'location_name':"Mumbai"}];
constructor(){
this.regions.push({'location_name':"All"}); -- Will add a value in the constructor
}
regionSelectionChange(regionName) {
console.log(regionName.value);
}
}
HTML代码:
<mat-form-field>
<mat-select [(value)]="regionOption" (selectionChange)="regionSelectionChange($event)" placeholder="Region">
<mat-option *ngFor="let region of regions" [value]="region.location_name">{{region.location_name}}
</mat-option>
</mat-select>
</mat-form-field>
我在 (selectionChange) 事件上有 mat-select 我收到未定义的值 $event.value
。它 returns 第一个 mat-option.mat 选项的正确值 'All' 它给出了 undefined
<mat-form-field>
<mat-select [(value)]="regionOption" (selectionChange)="regionSelectionChange($event)"
placeholder="Region">
<mat-option *ngFor="let region of regions" [value]="region.location_name">{{region.location_name}}</mat-option>
<mat-option [value]="All" >All</mat-option>
</mat-select>
</mat-form-field>
//ts
regionSelectionChange(regionName)
{
console.log(regionName);
}
将您的值绑定从 [value] 更改为值
<mat-option value="All">All</mat-option>
我会选择这个:
TS代码:
export class FormFieldOverviewExample {
regions: any[]= [{'location_name':"Pune"},{'location_name':"Mumbai"}];
constructor(){
this.regions.push({'location_name':"All"}); -- Will add a value in the constructor
}
regionSelectionChange(regionName) {
console.log(regionName.value);
}
}
HTML代码:
<mat-form-field>
<mat-select [(value)]="regionOption" (selectionChange)="regionSelectionChange($event)" placeholder="Region">
<mat-option *ngFor="let region of regions" [value]="region.location_name">{{region.location_name}}
</mat-option>
</mat-select>
</mat-form-field>