Uncaught InvalidStateError: Failed to set the 'value' property on 'HTMLInputElement': This input element accepts a filename, which may only be programmatically set to the empty string.

使用 HTML5 的圖片上傳api的時候報如下錯誤：

Uncaught InvalidStateError: Failed to set the 'value' property on 'HTMLInputElement': This input element accepts a filename, which may only be programmatically set to the empty string.

　出現這個bug的原因是，input元素 blur的時候，需要將上次圖片的input元素的value設置為空字符串，就不會報錯了。

http://stackoverflow.com/questions/29720794/jquery-select-input-file-and-also-set-it-to-another-input