I'm trying to make a shared service for my app.
import { Injectable } from '@angular/core';
@Injectable()
export class SharedService {
testService() {
console.log('share!');
}
}
Then I inject it in my app.component's providers but when I tried to call it in the constructor of a child component like this: constructor(public sharedService: SharedService) {}
I've got an error: Can't resolve all parameters for MyComponent
. I also tried to inject it in my app.module providers and also got this error. What should I do? How to inject it properly? Can anyone provide an example of proper shared service for antire app(it has several modules)?
I have routing sistem and I want to have a shared service and change it's data from the component which module is currently represented.
I believe you use latest version and want to use singleton service. For that you have to register your service in @NgModule({})
as shown here,
import {Sharedservice} from 'valid path';
@NgModule({
imports:[BroswerModule],
...
providers:[SharedService]
})
Now, In child and parent component just import Sharedservice at the top of the file.
NOTE : Remove providers:[SharedService]
from each component.
You need to set who's the provider for that service with providers
keyword in @Component
or @NgModule
annotation. This is well documented already zilion times, see:
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.