解决移动端 ios 系统键盘遮挡的问题

var isIPHONE = navigator.userAgent.toUpperCase().indexOf("IPHONE")!= -1;
if(isIPHONE){
 // 元素失去焦点隐藏iphone的软键盘
 function objBlur(obj,time){
  var startTime=0,endTime=0,
  time = !time?30:time,
  docTouchend = function(event){
   endTime = new Date().getTime();
   if(event.target!= obj && (endTime - startTime <300)){
    setTimeout(function(){
     obj.blur();
     document.removeEventListener("touchend", docTouchend,false);
    },time);
   }
  };
  document.addEventListener("touchstart",function(){
   startTime = new Date().getTime();
  });
  document.addEventListener("touchend", docTouchend,false);
 }
 $("input").on("focus",function(){
  var id = this.id;
  var self = this;
  var H = window.innerHeight;
  var pos = getPosition(self);
  if(isIPHONE){
   var input = new objBlur(self);
   input=null;
  }
 });
 function getPosition(target) {
  var left = 0, top = 0;
  do {
   left += target.offsetLeft || 0;
   top += target.offsetTop || 0;
   target = target.offsetParent;
  } while(target);
  return {
   left: left,
   top: top
  };
 }
}