从组件访问angular2指令

Question

I have created a directive for a textarea (TextAreaExt) and i want to call a method of that directive from a component it is used in. The selector of the directive is "textarea" (no attribute, affects all textarea elements). In my component if i do the following:

@ViewChild('TextAreaExt') txt: TextAreaExt;

I can call methods on txt successfully. But what if i had multiple textareas? I would like to do it like this instead:

@ViewChild('txt') txt: TextAreaExt;

Unfortunately, the above line does not return a TextAreaExt class, but instead returns an ElementRef.

How could i solve this problem so that i could have multiple text areas?

Answer 1

This should do what you want:

@ViewChild('txt', {read: TextAreaExt}) txt: TextAreaExt;

If there are more directives, components or other DI tokens registered for an element, read allows you to specify, which one you want to get returned.