替换菜单并将其放在滚动条的顶部

Question

我想用滚动条上的另一个替换导航菜单，并将新菜单粘贴在页面顶部。

对于粘性菜单部分，我使用了以下JavaScript代码：

 // Create a clone of the menu, right next to original.
$('.panel_menu').addClass('original').clone().insertAfter('.panel_menu').addClass('cloned').css('position','fixed').css('top','0').css('margin-top','0').css('z-index','500').removeClass('original').hide();

scrollIntervalID = setInterval(stickIt, 10);

function stickIt() {

  var orgElementPos = $('.original').offset();
  orgElementTop = orgElementPos.top;               

  if ($(window).scrollTop() >= (orgElementTop)) {

    // scrolled past the original position; now only show the cloned, sticky element.

    // Cloned element should always have same left position and width as original element.     
    orgElement = $('.original');
    coordsOrgElement = orgElement.offset();
    leftOrgElement = coordsOrgElement.left;  
    widthOrgElement = orgElement.css('width');
    $('.cloned').css('left',leftOrgElement+'px').css('top',0).css('width',widthOrgElement).show();
    $('.original').css('visibility','hidden');  
    $(".cloned").css('background-color', '#2f3a54');


  } else {
    // not scrolled past the menu; only show the original menu.
    $('.cloned').hide();

    $('.original').css('visibility','visible');     
  }
}; 

但我不知道如何执行替换零件。谢谢

编辑（答案）：所以我稍微修改了KLAJDI的答案，这是代码：

$(function(){
     // Check the initial Poistion of the Sticky Header
     var stickyHeaderTop = $('.panel_menu').offset().top;

     $(window).scroll(function(){
             if( $(window).scrollTop() > stickyHeaderTop ) {
                     orgElement = $('.panel_menu');
                     widthOrgElement = orgElement.css('width');
                     $('.panel_menu_clone').css({position: 'fixed', top: '0px'});
                     $('.panel_menu_clone').css('width',widthOrgElement).show();
                     $(".panel_menu_clone").css('background-color', '#2f3a54');  
             } else {
                     $('.panel_menu').show();
                     $('.panel_menu_clone').css('display', 'none');
             }
     });
});

Answer 1

你的意思是这样的：

 $(function(){ // Check the initial Poistion of the Sticky Header var stickyHeaderTop = $('#stickyheader').offset().top; $(window).scroll(function(){ if( $(window).scrollTop() > stickyHeaderTop ) { $('#stickyheader').css({position: 'fixed', top: '0px'}); $('#stickyalias').css('display', 'block'); } else { $('#stickyheader').css({position: 'static', top: '0px'}); $('#stickyalias').css('display', 'none'); } }); }); 

  table { background: black; color: white;} body, td { font: 13px sans-serif; } #stickyheader { width: 100%; height: 10px; } #stickyalias { display: none; height: 10px; } #unstickyheader { margin-bottom: 15px; } #othercontent { margin-top: 20px; } 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div id="unstickyheader"> <p>This is some text that comes before our <strong>Sticky Header</strong></p> </div> <div id="stickyheader"> <table width="100%"> <tr> <td>Sticky Text 1</td> <td>Sticky Text 2</td> <td>Sticky Text 3</td> <td>Sticky Text 4</td> <td>Sticky Text 5</td> </tr> </table> </div> <div id="stickyalias"></div> <div id="othercontent"> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> <p>Content Here<p> </div>