在我的应用程序中,我尝试放置一个按钮,显示/隐藏带有布尔组件属性的输入字段.如果按钮显示输入,则应在输入上设置焦点.但它似乎不起作用.如果我删除* ngIf,焦点指令工作正常.
我创建了一个显示我的意思的plunker.描述我的“问题”有点困难.
组件中的html
<input *ngIf="filterShow.options"
[focus]="filterFocus.options"
[(ngModel)]="filter.options">
<button type="button"
(click)="setShowFilter('options')">
focus
</button>
setShowFilter()函数
private setShowFilter(filter: string) {
this.filterShow[filter] = !this.filterShow[filter];
/* reset filter */
this.filter[filter] = "";
this.filterFocus[filter].emit(true);
}
focus.directive.ts
@Directive({
selector: '[focus]'
})
export class FocusDirective implements OnInit {
@Input('focus') focusEvent: EventEmitter<boolean>;
constructor(private elementRef : ElementRef,private renderer : Renderer ) { }
ngOnInit() {
this.focusEvent.subscribe(event => {
this.renderer
.invokeElementMethod(this.elementRef.nativeElement,'focus',[]);
});
}
}
EventEmitters用于输出,不用于输入.尝试这样的事情：
@Directive({
selector: '[focus]'
})
export class FocusDirective implements OnChanges {
@Input('focus') focus: boolean;
constructor(private elementRef : ElementRef,private renderer : Renderer ) { }
ngOnChanges() {
if (this.focus) {
this.renderer
.invokeElementMethod(this.elementRef.nativeElement,[]);
}
}
}
