Javascript priming的值';s滑块不';t更新
我有一个带有滑块和两个按钮的简单组件: app.component.htmlJavascript priming的值';s滑块不';t更新,javascript,angular,primeng,Javascript,Angular,Primeng,我有一个带有滑块和两个按钮的简单组件: app.component.html <p-slider [(ngModel)]="val" [min]="0" [max]="100" [step]="1"></p-slider> <button pButton type="button" label="Next" (click)="next()"></button> <button pButton type="button" label="Res
<p-slider [(ngModel)]="val" [min]="0" [max]="100" [step]="1"></p-slider>
<button pButton type="button" label="Next" (click)="next()"></button>
<button pButton type="button" label="Reset" (click)="reset()"class="ui-button-secondary"></button>
问题是,当我单击Next
按钮时,它什么也不做。它应该增加滑块的值
Stackblitz.这是因为
val
的值是未定义的。您应该将滑块值初始化为一些数字,如val:number=0
。当您调用next()
方法时,它会增加值undefined
,这将为您提供NAN
更新的app.component.ts:
import { Component } from '@angular/core';
import { SliderService } from './slider.service';
@Component({
selector: 'my-app',
templateUrl: './app.component.html',
styleUrls: [ './app.component.css' ]
})
export class AppComponent {
val: number = 0; // Initialize your val's value
next() {
this.val++;
}
reset() {
this.val = 0;
}
}
更新后的系统正在运行
import { Component } from '@angular/core';
import { SliderService } from './slider.service';
@Component({
selector: 'my-app',
templateUrl: './app.component.html',
styleUrls: [ './app.component.css' ]
})
export class AppComponent {
val: number = 0; // Initialize your val's value
next() {
this.val++;
}
reset() {
this.val = 0;
}
}