滚动触发特效

var scroll_obj = [‘.index_shuzi‘,‘.index_shop_category‘,‘.index_pro_box‘,‘.index_about_bg‘,‘.index_pro_more1‘,‘.index_pro_more2‘,‘.index_huanjing_bg‘,‘.index_news_bg‘];
  var index_shuzi_top = $(‘.index_shuzi‘).offset().top;
  var window_height = $(window).height();

  $(window).on(‘scroll‘, function () {

    let scorll_top = $(window).scrollTop();

    scroll_obj.forEach(element => {

      let top = $(element).offset().top;
      if (scorll_top + window_height > top){

        let funname = element.substr(1)+‘_fun‘;

        if(is_function(funname)){
          eval(funname+‘()‘);
        }else{
          $(element).addClass(‘cur‘)
        }
      
        let index = scroll_obj.indexOf(element);
        scroll_obj.splice(index, 1);
        return false
      }
    });
  }
  
  )

  function is_function(functionName){
    try {
        if (typeof eval(functionName) === "function") { 
            return true;
        } else { 
            return false;
        }
    } catch (e) {
       
    }
    return false;
}

  var index_shuzi_fun = function (){
    gundong(‘#index_sz1‘);
    gundong(‘#index_sz2‘);
    gundong(‘#index_sz3‘);
  }