Catches errors on the observable to be handled by returning a new observable or throwing an error.
返回新的可观察对象
import { Component, OnInit } from '@angular/core';
import { of } from 'rxjs/observable/of';
import { map, catchError, retry } from 'rxjs/operators';
@Component({
selector: 'app-error',
templateUrl: './error.component.html',
styleUrls: ['./error.component.css']
})
export class ErrorComponent implements OnInit {
constructor() { }
ngOnInit() {
of('Leo', 'Raph', 'Mikey', 'Don').pipe(
map(turtle => {
if (turtle === 'Mikey') {
throw new Error('出错了');
}
return turtle;
}),
catchError(err => of('Aioria', 'Mu'))
).subscribe(turtle => {
console.log(turtle);
});
}
}
继续抛出异常
import { Component, OnInit } from '@angular/core';
import { of } from 'rxjs/observable/of';
import { map, catchError, retry } from 'rxjs/operators';
@Component({
selector: 'app-error',
templateUrl: './error.component.html',
styleUrls: ['./error.component.css']
})
export class ErrorComponent implements OnInit {
constructor() { }
ngOnInit() {
of('Leo', 'Raph', 'Mikey', 'Don').pipe(
map(turtle => {
if (turtle === 'Mikey') {
throw new Error('出错了');
}
return turtle;
}),
catchError(err => {
throw new Error('继续抛出异常');
})
).subscribe(turtle => {
console.log(turtle);
});
}
}
重新尝试
import { Component, OnInit } from '@angular/core';
import { of } from 'rxjs/observable/of';
import { map, catchError, retry } from 'rxjs/operators';
@Component({
selector: 'app-error',
templateUrl: './error.component.html',
styleUrls: ['./error.component.css']
})
export class ErrorComponent implements OnInit {
constructor() { }
ngOnInit() {
of('Leo', 'Raph', 'Mikey', 'Don').pipe(
map(turtle => {
if (turtle === 'Mikey') {
throw new Error('出错了');
}
return turtle;
}),
retry(2),
catchError(err => of('Aioria', 'Mu'))
).subscribe(turtle => {
console.log(turtle);
});
}
}