IE8 file Upload file is empty problem

Today in the use of the application system before the discovery of the original can be used to upload the file today suddenly can not use, changed the browser to try the original is IE8, Firefox, Chrome does not have this problem, online check the original is a IE8 problem, really collapsed ...

IE8 based on security considerations, file upload only allows mouse clicks trigger file browsing and upload, if it is through JS triggered file browsing will cause upload failure (default Input[type=file] style is too bad, inconsistent with the existing system, So most system development will use the custom browse button through JS call the original input[type=file] onclick or onchange event method to achieve. Results this way IE8 unexpectedly not support ...

Solving method

Cover the top of the custom button with a Input[type=file browser, and then change the input[type=file] to transparent so that each time you click on a custom button, you actually click Input[type=file]. Note Input[type=file] Hide do not use Display:none or visiable:false, you should filter the way style= "Filter:alpha (opacity=0); Opacity:10"