1.edit "start" of your package.json to look below
定义一个叫做start的新命令
"start": "ng serve --proxy-config proxy.conf.json", 或者 "start": "ng serve --proxy-config proxy.conf.json --port=9000",
如果不加参数port，默认端口4200
2.create a new file called proxy.conf.json in the root of the project and inside of that define your proxies like below
创建一个proxy.conf.json文件，定义所有/api的请求重定向到http://api.yourdomai.com
{
"/api": {
"target": "http://api.yourdomai.com",
"secure": false
}
}3.Important thing is that you use npm start instead of ng serve
启动命令使用ng start，而非ng serve
参考资料
angular-cli server - how to proxy API requests to another server?
