我正在尝试使用express Js提供一些文件。我在heroku中部署了这个应用程序，它工作得很好。但是当我尝试使用前端（Angular）从我的应用程序发送请求时，它被 cors 阻塞。这只发生在文件发送路线上。
快递js代码：
const express = require('express');
var cors = require('cors')
const app = express();
const PORT = process.env.PORT || 8080;
app.use(express.static('public'));
app.use(cors());
app.use(function(req, res, next) {
res.setHeader('Access-Control-Allow-Origin', '*');
res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE');
res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
res.setHeader('Access-Control-Allow-Credentials', true);
next();
});
app.get('/', (req, res) => {
res.send('Hello World!');
});
app.get('/test', (req, res) => {
res.json({ username: 'Flavio' })
});
app.get('/:path_file', function(req, res){
console.log(req.params.path_file);
res.sendFile('public/'+req.params.path_file,{ root: __dirname });
});
app.listen(PORT, () => console.log(`Server listening on port: ${PORT}`));
角度请求代码：
export class AppComponent {
constructor(private processVisualisationService: ProcessVisualisationService,public http: HttpClient){
const optionRequete = {
headers: new HttpHeaders({
'Access-Control-Allow-Origin':'*'
})
};
this.http.get('https://safe-brook-89233.herokuapp.com/test',optionRequete).subscribe(data => {
console.log(data)
});
this.http.get('https://safe-brook-89233.herokuapp.com/c4_diagram.bpmn.txt',optionRequete).subscribe(data => {
console.log(data)
});
}
来自控制台的屏幕截图： 控制台
