拖動(dòng)from marker 可以正常移動(dòng) ,但是拖動(dòng)to 只能固定一個(gè)點(diǎn)位
$("#range").on("change", function () {

     
            var $this = $(this),
            from = $this.data("from");
            to = $this.data("to");
           
                var fromData = fromToDis(json.data,to);
                computeOffsetCommon(fromData,1,"起點(diǎn)");
       
                var toData = fromToDis(json.data,from);
                computeOffsetCommon(toData,2,"末點(diǎn)");
      
    });