text: var http = require('http');
  var qrcode = require('qrcode');
  
  http.createServer(function (req, res) {
  	// qrcode.toDataURL('https://github.com', function (err, url) {
  	// 	if(err){
  	// 		console.error(err);
  	// 	}
  	// 	res.end(
  	// 		"<!DOCTYPE html/><html><head><meta charset='utf-8'><title>二维码</title></head><body><p>请扫描二维码</p><img src='" + url + "'/></body></html>");
  	// });
  	qrcode.draw('https://github.com', function (err,canvas) {
  		res.end(canvas.toBuffer());
  	});
  }).listen(3000, function () {
  	console.log('Server at localhost:3000');
  })