html滚动条实现，超简单

在对应的div中，添加overflow,固定高度为400px

<div class="panel-body" style="height: 400px; overflow:scroll">
            <div style="border: 1px  #000000; width: 90%; margin: 0 auto;">
                <span>
        
            </span>
            </div>
        </div>

水平、垂直滚动条就都有了！也可固定width

垂直滚动条

<div class="panel-body" style="height: 400px; overflow-y:scroll">
            <div style="border: 1px  #000000; width: 90%; margin: 0 auto;">
                <span>
        
            </span>
            </div>
        </div>