jQuery如果高度

// 确保DOM加载完成
$(document).ready(function(){
    // 对于隐藏元素先显示再获取
    var $elem = $('#target');
    $elem.show();
    var height = $elem.height();
    $elem.hide();
    
    console.log(height);
});

// 强制覆盖样式
$('#target').css({
    'height': '200px !important',
    'box-sizing': 'content-box'
});

// 检查父元素限制
var parentHeight = $('#target').parent().height();
if(parentHeight < 200){
    $('#target').parent().height(200);
}

// 使用requestAnimationFrame优化
function animateHeight(element, targetHeight) {
    var startHeight = element.height();
    var startTime = null;
    
    function step(timestamp) {
        if (!startTime) startTime = timestamp;
        var progress = timestamp - startTime;
        var percentage = Math.min(progress / 300, 1); // 300ms动画时间
        
        element.height(startHeight + (targetHeight - startHeight) * percentage);
        
        if (percentage < 1) {
            window.requestAnimationFrame(step);
        }
    }
    
    window.requestAnimationFrame(step);
}

animateHeight($('#box'), 500);

var $element = $('#target');
var height = $element.height();

// 原生等效方法
document.getElementById('target').getBoundingClientRect().height;