1 支查解决办法

确定元素在 jQuery 中是否可见的方法

<script>
if ($("#myelement").is(":visible")){alert ("#myelement is visible");}
if ($("#myelement").is(":hidden")){alert ("#myelement is hidden"); }
</script>

全部环圈可见可见div id 'maylement' 元素的孩子:

$("#myelement div:visible").each( function() {
 //Do something
});

在jQuery的源头钻探

这就是jQuery如何执行这个功能:

jQuery.expr.filters.visible = function( elem ) {
    return !!( elem.offsetWidth || elem.offsetHeight || elem.getClientRects().length );
};

2 • 如何检查元素是否在屏幕外 - CSS

使用元素. getBoundingClientRect () 您可以很容易地检测到您的元素是否在您视图的边界之内( 屏幕上或屏幕下) :

jQuery.expr.filters.offscreen = function(el) {
  var rect = el.getBoundingClientRect();
  return (
           (rect.x + rect.width) < 0 
             || (rect.y + rect.height) < 0
             || (rect.x > window.innerWidth || rect.y > window.innerHeight)
         );
};

然后,你可以以几种方式使用:

// Returns all elements that are offscreen
$(':offscreen');

// Boolean returned if element is offscreen
$('div').is(':offscreen');

如果使用角,请检查:不要使用与角的隐藏属性

if($("h1").is(":hidden")){
    // your code..
}

使用任何可见的选择器或隐藏的选择器检查粘度 :

1. 使用使用: 可见选择器 - jQuery (“ : 可见” )
2. 使用: hidden 选择器 - jQuery (“ : hidden ” )

使用.toggle ()- 显示和隐藏元素

function checkVisibility() {
    // check if element is hidden or not and return true false
    console.log($('#element').is(':hidden'));

    // check if element is visible or not and return true false
    console.log($('#element').is(':visible'));

    if ( $('#element').css('display') == 'none' || $('#element').css("visibility") == "hidden"){
        console.log('element is hidden');
    } else {
        console.log('element is visibile');
    }
}

checkVisibility()
$('#toggle').click(function() {
    $('#element').toggle()
    checkVisibility()
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<button id='toggle'>Toggle</button>
<div style='display:none' id='element'>
    <h1>Hello</h1>
    <p>it's visible</p>
</div>

下面的代码检查元素是否隐藏在 jQuery 中或可见

// You can also do this...

        $("button").click(function(){
            // show hide paragraph on button click
            $("p").toggle("slow", function(){
                // check paragraph once toggle effect is completed
                if($("p").is(":visible")){
                    alert("The paragraph  is visible.");
                } else{
                    alert("The paragraph  is hidden.");
                }
            });
        });

jQuery 解决方案, 但对于想更改按钮文字的人来说,

$(function(){
  $("#showHide").click(function(){
    var btn = $(this);
    $("#content").toggle(function () {
      btn.text($(this).css("display") === 'none' ? "Show" : "Hide");
    });
   });
 });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<button id="showHide">Hide</button>
<div id="content">
  <h2>Some content</h2>
  <p>
  What is Lorem Ipsum? Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged.
  </p>
</div>

用于检查元素是否可见、未显示或甚至不透明水平的扩展功能

它返回时返回false如果元素不可见。

function checkVisible(e) {
    if (!(e instanceof Element)) throw Error('not an Element');
    const elementStyle = getComputedStyle(e);
    if (elementStyle.display === 'none' || elementStyle.visibility !== 'visible' || elementStyle.opacity < 0.1) return false;
    if (e.offsetWidth + e.offsetHeight + e.getBoundingClientRect().height +
        e.getBoundingClientRect().width === 0) {
        return false;
    }
    const elemCenter   = {
        x: e.getBoundingClientRect().left + e.offsetWidth / 2,
        y: e.getBoundingClientRect().top + e.offsetHeight / 2
    };
    if (elemCenter.x < 0 || elemCenter.y < 0) return false;
    if (elemCenter.x > (document.documentElement.clientWidth || window.innerWidth)) return false;
    if (elemCenter.y > (document.documentElement.clientHeight || window.innerHeight)) return false;
    let pointContainer = document.elementFromPoint(elemCenter.x, elemCenter.y);
    do {
        if (pointContainer === e) return true;
    } while (pointContainer = pointContainer.parentNode);
    return false;
}