如何存储比通过Angular中的Output（）和EventEmitter（）传入的最近值更多的值？(How do I store more than the most recent value passed in via Output() and EventEmitter() in Angular?)

 我在我的Angular应用程序中使用自定义输出来在组件之间发送用户选择的值。 现在工作的是，每当用户点击一个复选框项时，该值就会发送到我的子组件，在那里我可以看到它打印到控制台。 问题是，当用户点击另一个选择，我得到该值发送，但以前发送的值现在返回未定义。 换句话说，我只能获得最近的价值。 我的问题是：如何存储传递的值，以便我可以用每个用户选择的值构建一个过滤器列表，而不是最新的值？ 
 
 这些值通过Angular的Output（）和EventEmitter（）传递给子组件，并发送给一个“getFilters（$ event）”函数，如下所示： 
 
    <div class="page-content">
            <list [records]="records" 
                (sendChange)="getFilters($event)"
                (sendLanguage)="getFilters($event)"
                (sendBranch)="getFilters($event)"
                (sendZipcode)="getFilters($event)">
            </list>
    </div>
 
 我试图接收这些值，然后将它们存储在变量中。 但是当我控制台记录这些变量时，我仍然只看到最近的选择。 我如何存储所有选择以构建新的查询？ 
 
getFilters(page, language, zipcode, branch) {
    const paged = page;
    const lang = language;
    const zip = zipcode;
    const city = branch;
    console.log('Stored: ' + paged + ' ' + lang + ' ' + zip + ' ' + city);
}
 
 所以，如果“zipcode”是传入的最后一个值，这就是我在控制台中看到的 - （所有其他先前发送的值现在都是“undefined”）： 
 
Stored: 90001 undefined undefined undefined undefined

I am using custom outputs in my Angular app to send user-selected values between components. Right now what's working is that each time a user clicks a check-box item, that value is sent through to my sub-component, where I can see it print to the console. The problem is that when the user clicks another selection, I get that value sent through, but the previous sent value now returns undefined. In other words, I'm only ever getting the most recent value. My question is: how do I store those values being passed down, so that I can built a filter list with each of the user-selected values, rather than just the most recent one?
 
The values are being passed down to the sub-component with Angular's Output() and EventEmitter(), and sent to a "getFilters($event)" function, like this:
 
    <div class="page-content">
            <list [records]="records" 
                (sendChange)="getFilters($event)"
                (sendLanguage)="getFilters($event)"
                (sendBranch)="getFilters($event)"
                (sendZipcode)="getFilters($event)">
            </list>
    </div>
 
I have tried receiving those values, and then storing them in variables. But when I console log those variables, I'm still only ever seeing the most recent selection. How can I store all of the selections to be able to build a new query?
 
getFilters(page, language, zipcode, branch) {
    const paged = page;
    const lang = language;
    const zip = zipcode;
    const city = branch;
    console.log('Stored: ' + paged + ' ' + lang + ' ' + zip + ' ' + city);
}
 
So, if "zipcode" was the last value passed in, this is what I see in the console - (all other previously sent values are now "undefined"):
 
Stored: 90001 undefined undefined undefined undefined

原文：https://stackoverflow.com/questions/43672454