当我在 ngOnInit() 中使用 router.getCurrentNavigation() 时,它会给我类型错误,但是当我在构造函数中使用它时,它工作正常,为什么?
when i use router.getCurrentNavigation() inside ngOnInit() it gives me type error but when i use it inside constructor it works fine, why?
首发 -
export class HeaderComponent implements OnInit {
constructor(private route: ActivatedRoute, private router: Router) {}
onClick() {
const navigationExtras: NavigationExtras = {
state: {
transd: 'TRANS001',
workQueue: false,
services: 10,
code: '003',
},
};
this.router.navigate(['/auth'], navigationExtras);
}
}
AuthComponent -
在 ngOnInit() 内部使用时:
ngOnInit(): void {
this.authService.authError.subscribe(
(error) => (this.errorMessage = error)
);
const navigation = this.router.getCurrentNavigation();
const state = navigation.extras.state as {
transId: string;
workQueue: boolean;
services: number;
code: string;
};
console.dir(state);
}
在 ngOnInit() 内部使用时出现错误:
core.js:5980 ERROR TypeError: Cannot read property 'extras' of null
at AuthComponent.ngOnInit (auth.component.ts:26)
at callHook (core.js:2486)
at callHooks (core.js:2457)
at executeInitAndCheckHooks (core.js:2408)`
at refreshView (core.js:9207)
at refreshEmbeddedViews (core.js:10312)
at refreshView (core.js:9216)
at refreshComponent (core.js:10358)
at refreshChildComponents (core.js:8989)
at refreshView (core.js:9242)
但是当我把它放在构造函数中时它工作正常:
constructor(private authService: AuthService, private router: Router) {
const navigation = this.router.getCurrentNavigation();
const state = navigation.extras.state as {
transId: string;
workQueue: boolean;
services: number;
code: string;
};
console.dir(state);
}
所以,为什么它在构造函数内部工作,而不是在 ngOnInit 内部工作?
在 ngOnInit() 中你可以使用历史:
ngOnInit() {
const state = history.state;
}
有必要在构造函数中调用 getCurrentNavigation(),因为在 ngOnInit() 中导航已经完成。
首发 -
export class HeaderComponent implements OnInit {
constructor(private route: ActivatedRoute, private router: Router) {}
onClick() {
const navigationExtras: NavigationExtras = {
state: {
transd: 'TRANS001',
workQueue: false,
services: 10,
code: '003',
},
};
this.router.navigate(['/auth'], navigationExtras);
}
}
AuthComponent - 在 ngOnInit() 内部使用时:
ngOnInit(): void {
this.authService.authError.subscribe(
(error) => (this.errorMessage = error)
);
const navigation = this.router.getCurrentNavigation();
const state = navigation.extras.state as {
transId: string;
workQueue: boolean;
services: number;
code: string;
};
console.dir(state);
}
在 ngOnInit() 内部使用时出现错误:
core.js:5980 ERROR TypeError: Cannot read property 'extras' of null
at AuthComponent.ngOnInit (auth.component.ts:26)
at callHook (core.js:2486)
at callHooks (core.js:2457)
at executeInitAndCheckHooks (core.js:2408)`
at refreshView (core.js:9207)
at refreshEmbeddedViews (core.js:10312)
at refreshView (core.js:9216)
at refreshComponent (core.js:10358)
at refreshChildComponents (core.js:8989)
at refreshView (core.js:9242)
但是当我把它放在构造函数中时它工作正常:
constructor(private authService: AuthService, private router: Router) {
const navigation = this.router.getCurrentNavigation();
const state = navigation.extras.state as {
transId: string;
workQueue: boolean;
services: number;
code: string;
};
console.dir(state);
}
所以,为什么它在构造函数内部工作,而不是在 ngOnInit 内部工作?
在 ngOnInit() 中你可以使用历史:
ngOnInit() {
const state = history.state;
}
有必要在构造函数中调用 getCurrentNavigation(),因为在 ngOnInit() 中导航已经完成。