本文介绍了Angular2 ngModelChange以前的值的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
是否可以获取ngModelChange上字段的先前(最后一个)值? 我拥有的东西是这样的
Is there a way to get the previous(last) value of a field on ngModelChange? What I have goes something like this
HTML
<input type="text" [(ngModel)]="text" (ngModelChange)="textChanged($event)">处理程序
private textChanged(event) { console.log('changed', this.text, event); }我得到的是
changed *newvalue* *newvalue*当然我可以使用另一个变量来保留较旧的值,但是还有更好的方法吗?
Of course I can keep the older value using another variable, but is there a better way?
推荐答案所以发现有点奇怪(至少对于我)可能的解决方案,只需更改相关代码即可。因此,在 [(ngModel)] 之前分配(ngModelChange)属性时,我得到的是使用相同处理程序执行的操作:
So found kinda weird(at least for me) possible solution for this with least changes in the code in question. So on assigning the (ngModelChange) attribute before [(ngModel)] what I get is following with the same handler:
changed *older value* *new value*我在 this.text 中得到新值,如下所示:
I get the new value in this.textlike so:
setTimeout(() => console.log(this.text), 0);更多推荐
Angular2 ngModelChange以前的值
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