这是我解决这个问题的方法：

$(document).ready(function() {
  $('#user-toggle').click(function(e) {
    $('#user-nav').toggle();
    e.stopPropagation();
  });

  $('body').click(function() {
    $('#user-nav').hide(); 
  });

  $('#user-nav').click(function(e){
    e.stopPropagation();
  });
});

标记为接受答案的答案没有考虑到元素上可以有覆盖，如对话框、弹出窗口、日期选择器等。单击这些按钮不应隐藏元素。

我制作了自己的版本，确实考虑到了这一点。它是作为KnockoutJS绑定创建的，但它可以很容易地仅转换为jQuery。

它通过第一次查询所有具有z索引或绝对位置的可见元素来工作。然后，如果在外部单击，它会根据我想要隐藏的元素来测试这些元素。如果是命中，我会计算一个新的边界矩形，该矩形考虑到覆盖边界。

ko.bindingHandlers.clickedIn = (function () {
    function getBounds(element) {
        var pos = element.offset();
        return {
            x: pos.left,
            x2: pos.left + element.outerWidth(),
            y: pos.top,
            y2: pos.top + element.outerHeight()
        };
    }

    function hitTest(o, l) {
        function getOffset(o) {
            for (var r = { l: o.offsetLeft, t: o.offsetTop, r: o.offsetWidth, b: o.offsetHeight };
                o = o.offsetParent; r.l += o.offsetLeft, r.t += o.offsetTop);
            return r.r += r.l, r.b += r.t, r;
        }

        for (var b, s, r = [], a = getOffset(o), j = isNaN(l.length), i = (j ? l = [l] : l).length; i;
            b = getOffset(l[--i]), (a.l == b.l || (a.l > b.l ? a.l <= b.r : b.l <= a.r))
                && (a.t == b.t || (a.t > b.t ? a.t <= b.b : b.t <= a.b)) && (r[r.length] = l[i]));
        return j ? !!r.length : r;
    }

    return {
        init: function (element, valueAccessor) {
            var target = valueAccessor();
            $(document).click(function (e) {
                if (element._clickedInElementShowing === false && target()) {
                    var $element = $(element);
                    var bounds = getBounds($element);

                    var possibleOverlays = $("[style*=z-index],[style*=absolute]").not(":hidden");
                    $.each(possibleOverlays, function () {
                        if (hitTest(element, this)) {
                            var b = getBounds($(this));
                            bounds.x = Math.min(bounds.x, b.x);
                            bounds.x2 = Math.max(bounds.x2, b.x2);
                            bounds.y = Math.min(bounds.y, b.y);
                            bounds.y2 = Math.max(bounds.y2, b.y2);
                        }
                    });

                    if (e.clientX < bounds.x || e.clientX > bounds.x2 ||
                        e.clientY < bounds.y || e.clientY > bounds.y2) {

                        target(false);
                    }
                }
                element._clickedInElementShowing = false;
            });

            $(element).click(function (e) {
                e.stopPropagation();
            });
        },
        update: function (element, valueAccessor) {
            var showing = ko.utils.unwrapObservable(valueAccessor());
            if (showing) {
                element._clickedInElementShowing = true;
            }
        }
    };
})();

我在一些jQuery日历插件中找到了这个方法。

function ClickOutsideCheck(e)
{
  var el = e.target;
  var popup = $('.popup:visible')[0];
  if (popup==undefined)
    return true;

  while (true){
    if (el == popup ) {
      return true;
    } else if (el == document) {
      $(".popup").hide();
      return false;
    } else {
      el = $(el).parent()[0];
    }
  }
};

$(document).bind('mousedown.popup', ClickOutsideCheck);

用纯JavaScript编写的方法

let menu = document.getElementById("menu");

document.addEventListener("click", function(){
    // Hide the menus
    menu.style.display = "none";
}, false);

document.getElementById("menuscontainer").addEventListener("click", function(e){
    // Show the menus
    menu.style.display = "block";
    e.stopPropagation();
}, false);

外部点击插件！

用法：

$('.target-element').outsideClick(function(event){
    //code that fires when user clicks outside the element
    //event = the click event
    //$(this) = the '.target-element' that is firing this function 
}, '.excluded-element')

它的代码：

(function($) {

//when the user hits the escape key, it will trigger all outsideClick functions
$(document).on("keyup", function (e) {
    if (e.which == 27) $('body').click(); //escape key
});

//The actual plugin
$.fn.outsideClick = function(callback, exclusions) {
    var subject = this;

    //test if exclusions have been set
    var hasExclusions = typeof exclusions !== 'undefined';

    //switches click event with touch event if on a touch device
    var ClickOrTouchEvent = "ontouchend" in document ? "touchend" : "click";

    $('body').on(ClickOrTouchEvent, function(event) {
        //click target does not contain subject as a parent
        var clickedOutside = !$(event.target).closest(subject).length;

        //click target was on one of the excluded elements
        var clickedExclusion = $(event.target).closest(exclusions).length;

        var testSuccessful;

        if (hasExclusions) {
            testSuccessful = clickedOutside && !clickedExclusion;
        } else {
            testSuccessful = clickedOutside;
        }

        if(testSuccessful) {
            callback.call(subject, event);
        }
    });

    return this;
};

}(jQuery));

根据此答案改编https://stackoverflow.com/a/3028037/1611058

这对我有用

$("body").mouseup(function(e) {
    var subject = $(".main-menu");
    if(e.target.id != subject.attr('id') && !subject.has(e.target).length) {
        $('.sub-menu').hide();
    }
});