清除浮动之后有了高度，还是不占位置，下面的元素footer还能挤上来

<!--html部分-->
<div class="pro_bd">
    		<ul class="clearfix">
    			<li>
    				<div>
    				    <img src="images/1.png">
    				</div>
    				<div class="pro_title">
    					Think PHP 5.0 博客系统实战项目演练
    				</div>
    				<p><span>高级</span>  •  1125人在学习</p>
    			</li>
    			<li>
    				<div>
    				    <img src="images/2.png">
    				</div>
    				<div class="pro_title">
    					Android 网络图片加载框架详解
    				</div>
    				<p><span>高级</span>  •  1125人在学习</p>
    			</li>
    			    <li>
    				<div>
    				    <img src="images/3.png">
    				</div>
    				<div class="pro_title">
    					Angular 2 最新框架+主流技术+项目实战
    				</div>
    				<p><span>高级</span>  •  1125人在学习</p>
    			</li>
    			    <li>
    				<div>
    				    <img src="images/4.png">
    				</div>
    				<div class="pro_title">
    					ndroid Hybrid APP开发实战 H5+原生！
    				</div>
    				<p><span>高级</span>  •  1125人在学习</p>
    			</li>
    			    <li>
    				<div>
    				    <img src="images/4.png">
    				</div>
    				<div class="pro_title">
    					ndroid Hybrid APP开发实战 H5+原生！
    				</div>
    				<p><span>高级</span>  •  1125人在学习</p>
    			</li>
    		</ul>
    	</div>
<footer>
    	<div class="w"></div>
</footer>



/*css部分*/

footer {
	height: 418px;
	background-color: #fff;
}
.clearfix:after {
	visibility: hidden;
	clear:both;
	display:block;
	content:"";
	height:0;
}
.clearfix{
	*zoom:1;
}

博主讲清一点

看一下小编的这篇博文吧！https://blog.csdn.net/qq_45404396/article/details/110406593