lanch.json
其中路径 ${workspaceRoot} 为项目根目录， 而 ${ workspaceFolder }为lanch.json所在路径，调试时需要注意webRoot设置，否则无法调试。
调试需要先cd到项目路径，再命令：ng s，完成后启动vsc调试
{
“version”: “0.2.0”,
“configurations”: [ {
“type”: “chrome”,
“request”: “launch”,
“name”: “Launch Chrome against localhost”,
“url”: “http://localhost:4200”,
“webRoot”: “${workspaceRoot}/ng-sample”,
“sourceMaps”: true,
“userDataDir”: “${workspaceRoot}/.vscode/chrome” } ]}