express设置跨域

在app.js的设置中添加

//设置允许跨域访问该服务.
app.all('*', function (req, res, next) {
    res.header('Access-Control-Allow-Origin', '*');
    res.header('Access-Control-Allow-Headers', 'Content-Type');
    res.header('Access-Control-Allow-Methods', '*');
    res.header('Content-Type', 'application/json;charset=utf-8');
    next();
  });