Question

我在页面右侧有一个固定的div。我将其设置为可与页面一起滚动而不与页脚重叠，并且效果很好。问题是向上滚动时它与导航重叠。有什么办法可以使两者都起作用吗？我试图创建一个新功能

function checkOffset() {
    var a = $(document).scrollTop() + window.innerHeight;
    var b = $('#footer').offset().top;

    if (a < b) {
        $('#social-float').css('bottom', '10px');
    } else {
        $('#social-float').css('bottom', (10 + (a - b)) + 'px');
    }
}
$(document).ready(checkOffset);
$(document).scroll(checkOffset);

<nav class="nav">Nav Sample</nav>

<div id="social-float">
    <div class="sf-twitter">twitter</div>
    <div class="sf-facebook">facebook</div>
</div>

<div id="footer">footer sample</div>

Answer 1

Here查看此小提琴以寻找解决方案。我在页面上添加了调试文本，并且还考虑了导航栏可能由于顶部的其他div而偏移的情况。

/** 
 * This function checks for both top and bottom edges to position itself
 * on the page
 */
function checkOffset() {
    var documentTop = $(document).scrollTop();
    var currentScrollOffset = documentTop + window.innerHeight;
    var footerOffset = $('#footer').offset().top;
    var navbarEffectiveHeight = $('.nav').outerHeight() + $('.nav').offset().top;
    var $fixedElem = $('#social-float');
    var fixedElemHeight = $fixedElem.outerHeight();

		// until page scroll crosses navbar bottom edge (offset)
    if (currentScrollOffset < navbarEffectiveHeight) {
    		$fixedElem.css('top', (currentScrollOffset + 10) + 'px');
        $fixedElem.css('bottom', 'unset');
    // page scroll crossed navbar bottom edge but not to extend of the height of fixed div
    // including the top and bottom spacing for it which is 20px
    } else if (currentScrollOffset < navbarEffectiveHeight + fixedElemHeight + 20) {
    		$fixedElem.css('top', (window.innerHeight - (currentScrollOffset - navbarEffectiveHeight) + 10) + 'px');
        $fixedElem.css('bottom', 'unset');
    // page scroll hasn't crossed footer top edge (offset)
    } else if (currentScrollOffset < footerOffset) {
        $fixedElem.css('bottom', '10px');
        $fixedElem.css('top', 'unset');
    // page scroll crossed footer top edge (offset)
    } else {
        $fixedElem.css('bottom', (10 + (currentScrollOffset - footerOffset)) + 'px');
        $fixedElem.css('top', 'unset');
    }
}


$(document).ready(checkOffset);
$(document).scroll(checkOffset);

从顶部和底部偏移固定div

1 个答案: