示例代码: css部分: #content{border: 1px solid saddlebrown;padding: 16px;border-radius: 2px} .list {top: 15px;width: 140px;height: 40px; border:1px solid #0082E6; display:inline-block;border-radius: 2px;position: relative; line-height: 40px;} #file{position: absolute;opacity: 0;color:white;width: 100%