如何在角度使用代理解决CORS问题

Question

我正在使用Express Node后端和前端进行角度处理。问题是当我将我的API集成到angular时出现了CORS问题。在开发人员控制台内部，我遇到了这样的错误：“ XmlHttpRequet无法加载http://localhost:3000/student No Access-Control-Allow-Origin”

我尝试代理后端，在angular项目内添加proxy-confg.json。但结果也一样。仍然有CORS问题。

// node js endpoint
ApienpointUrl = 'http://localhost:4200/stdApi/student';

// getting data from endpoint
getStudentfromMock() {
return this.http.get(this.ApienpointUrl).pipe(
  map((res: any) => res),
  catchError(this.handleError)
);
}

这里是角度项目proxy.conf.json中的Proxy配置

{
  "/stdApi/*": {
    "target": "http://localhost:3000",
    "secure": false,
    "logLevel": "debug",
    "changeOrigin": true
  }
}

我遇到这样的错误：-

"XmlHttpRequet cannot load http://localhost:4200/stdApi/student No Access-Control-Allow-Origin. header is present on the request resources origin 'http://localhost:3000' therefor not allowed access".

Answer 1

将此代码添加到app.js文件中。

app.use((req, res, next) => {
   // Website you wish to allow to connect
   res.setHeader('Access-Control-Allow-Origin', '*');

   // Request methods you wish to allow
   res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');

  // Request headers you wish to allow
  res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With, content-type, token, language');

   // Set to true if you need the website to include cookies in the requests sent
   // to the API (e.g. in case you use sessions)
   res.setHeader('Access-Control-Allow-Credentials', true);

   // Pass to next layer of middleware
   next(); 
});

并重新启动服务器。