问题
I want to link multiple <material-dropdown-select>, using [(ngModel)] + (ngModelChange), making them dependent. (So not by using *ngFor + <material-select-item>.)
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.
I tried with querySelector() but obviously, this is not the good way.
Maybe with ViewChild/ViewChildren but the options list is not updated???
回答1:
Well I finally get what I needed.
I used @ViewChild to target the element in the page.
But changing the options "was tricky", as I had to first :
MaterialDropdownSelectComponent.options.dispose();
then
- add the new list…
without the first step, the SelectionOptions<dynamic> is not updated…
来源：https://stackoverflow.com/questions/52592943/dependent-material-dropdown-select