ASP.NET Web Forms - Button not working inside <iframe> in IE9 and below
问题 I have an ASP.NET Web Forms page that has a form in it and I load it in an <iframe> as a popup. In all modern browsers it works great. In IE9 and below, however, things are weird. One file input element failed to open the file selection dialog when clicking on its browse button. After fixing this (with a JS trick), I saw another problem. Another button inside the form with this attribute for postback: onclick="javascript:WebForm_DoPostBackWithOptions(new WebForm_PostBackOptions("btnUpload", "