jq判断是PC还是手机端的方法

$(function(){
  //判断是否是手机
  var mobile_flag = isMobile();
  if(mobile_flag){
    $('.now_qq').attr('href',"mqqwpa://im/chat?chat_type=wpa&uin=<?php echo $qq['qq']?>&version=1&src_type=web&web_src=lvlingseeds.com");
  }else{
    $('.now_qq').attr('href',"tencent://message/?Site=baidu.com&uin=<?php echo $qq['qq']?>&Menu=yes");
  }
})
 
function isMobile() {
  var userAgentInfo = navigator.userAgent;
  var mobileAgents = [ "Android", "iPhone", "SymbianOS", "Windows Phone", "iPad","iPod"];
  var mobile_flag = false;
  //根据userAgent判断是否是手机
  for (var v = 0; v < mobileAgents.length; v++) {
      if (userAgentInfo.indexOf(mobileAgents[v]) > 0) {
          mobile_flag = true;
          break;
      }
  }
  var screen_width = window.screen.width;
  var screen_height = window.screen.height;   

   //根据屏幕分辨率判断是否是手机
   if(screen_width < 500 && screen_height < 800){
       mobile_flag = true;
  }
  return mobile_flag;
}