Uncaught DOMException: Failed to set the 'value' property on 'HTMLInputElement': This input element

完整的错误信息：Uncaught DOMException: Failed to set the 'value' property on 'HTMLInputElement': This input element accepts a filename, which may only be programmatically set to the empty string.

这个错误的意思就是说，不能为<input type="file" />的标签元素添加value属性！