针对这个问题,我们需要对拦截器中的类型进行检查。通常,这个错误是由于拦截器的返回类型与请求类型不同所导致的。以下是一个可能出现这个问题的示例:
import { Injectable } from '@angular/core';
import { HttpInterceptor, HttpEvent, HttpHandler, HttpRequest } from '@angular/common/http';
import { Observable } from 'rxjs';
@Injectable()
export class MyHttpInterceptor implements HttpInterceptor {
intercept(req: HttpRequest, next: HttpHandler): Observable> {
// 操作请求
const modifiedReq = req.clone({
headers: req.headers.set('Authorization', 'Bearer my-auth-token')
});
// 发送请求
return next.handle(modifiedReq);
}
}
在这个示例中,拦截器只是对请求进行了修改,而返回类型是 Observable
。但是,如果我们在直接返回响应的时候,就无法正确匹配类型。比如:
import { Injectable } from '@angular/core';
import { HttpInterceptor, HttpEvent, HttpHandler, HttpRequest, HttpResponse } from '@angular/common/http';
import { Observable } from 'rxjs';
@Injectable()
export class MyHttpInterceptor implements HttpInterceptor {
intercept(req: HttpRequest, next: HttpHandler): Observable> {
// 操作请求
const modifiedReq = req.clone({
headers: req.headers.set('Authorization', 'Bearer my-auth-token')
});
// 发送请求
return next.handle(modifiedReq).pipe(
tap(event => {
if (event instanceof HttpResponse) {
console.log(event.body);
// 返回格式不匹配
return { status: 200, data: event.body };
}
})
);
}
}
解决这个问题的方法是将拦截器的返回类型与请求类型保持一致。对于这个示例来说,应该返回一个 Observable
类型的对象。以下是修改后的代码: