问题描述
我想链接多个，使用[(ngModel)] + (ngModelChange)，使得他们依赖.(所以不能使用 *ngFor + .)
I want to link multiple <material-dropdown-select>, using [(ngModel)] + (ngModelChange), making them dependent. (So not by using *ngFor + <material-select-item>.)
但我没有找到如何使这些 <material-dropdown-select> 依赖，这样当父"被更新时，第一个孩子"被更新/重置，并且然后当第一个孩子被选中时，第二个被重置/更新，依此类推.
But I do not find how to make these <material-dropdown-select> dependent, such that when the "parent" is updated, the "first child" is updated/reset, and then when the first child is selected, the second is reset/updated, and so on.
我尝试过 querySelector() 但显然，这不是好方法.
I tried with querySelector() but obviously, this is not the good way.
也许使用 ViewChild/ViewChildren 但选项列表没有更新???
Maybe with ViewChild/ViewChildren but the options list is not updated???
推荐答案
好吧，我终于得到了我需要的东西.
Well I finally get what I needed.
我使用 @ViewChild 来定位页面中的元素.
I used @ViewChild to target the element in the page.
但是更改选项很棘手"，因为我必须首先:
But changing the options "was tricky", as I had to first :
MaterialDropdownSelectComponent.options.dispose();
然后
- 添加新列表...
没有第一步，SelectionOptions 不会更新...
without the first step, the SelectionOptions<dynamic> is not updated…
这篇关于相关的<material-dropdown-select>的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！