在做項目項目中經常需要上傳文件，類型也就那幾種。雖然在js中加了上傳文件類型的限制，但是為了減少因為用戶選擇不當而造成的反復檢驗。可以在input標簽上加上accept屬性。這種限制只是優化了選擇文件的過程，但是沒法真正做到限制文件類型因為：
看到沒有，是可以選擇的。所以還得以自己的驗證代碼為准。
瀏覽器支持情況
Internet Explorer 10、Firefox、Opera、Chrome 和 Safari 6 支持 accept 屬性。
注意：Internet Explorer 9 及之前的版本都不支持 <input> 標簽的 accept 屬性。
用法
可以單個限制使用也可以組合使用 比如：
<input accept="audio/*,video/*,image/*" />
<input accept="audio/*" />
<input accept="image/png" />
另外附上一些文件對應類型
*.3gpp audio/3gpp， video/3gpp 3GPP Audio/Video *.ac3 audio/ac3 AC3 Audio *.asf allpication/vnd.ms-asf Advanced Streaming Format *.au audio/basic AU Audio *.css text/css Cascading Style Sheets *.csv text/csv Comma Separated Values *.doc application/msword MS Word Document *.dot application/msword MS Word Template *.dtd application/xml-dtd Document Type Definition *.dwg image/vnd.dwg AutoCAD Drawing Database *.dxf image/vnd.dxf AutoCAD Drawing Interchange Format *.gif image/gif Graphic Interchange Format *.htm text/html HyperText Markup Language *.html text/html HyperText Markup Language *.jp2 image/jp2 JPEG-2000 *.jpe image/jpeg JPEG *.jpeg image/jpeg JPEG *.jpg image/jpeg JPEG *.js text/javascript， application/javascript JavaScript *.json application/json JavaScript Object Notation *.mp2 audio/mpeg， video/mpeg MPEG Audio/Video Stream， Layer II *.mp3 audio/mpeg MPEG Audio Stream， Layer III *.mp4 audio/mp4， video/mp4 MPEG-4 Audio/Video *.mpeg video/mpeg MPEG Video Stream， Layer II *.mpg video/mpeg MPEG Video Stream， Layer II *.mpp application/vnd.ms-project MS Project Project *.ogg application/ogg， audio/ogg Ogg Vorbis *.pdf application/pdf Portable Document Format *.png image/png Portable Network Graphics *.pot application/vnd.ms-powerpoint MS PowerPoint Template *.pps application/vnd.ms-powerpoint MS PowerPoint Slideshow *.ppt application/vnd.ms-powerpoint MS PowerPoint Presentation *.rtf application/rtf， text/rtf Rich Text Format *.svf image/vnd.svf Simple Vector Format *.tif image/tiff Tagged Image Format File *.tiff image/tiff Tagged Image Format File *.txt text/plain Plain Text *.wdb application/vnd.ms-works MS Works Database *.wps application/vnd.ms-works Works Text Document *.xhtml application/xhtml+xml Extensible HyperText Markup Language *.xlc application/vnd.ms-excel MS Excel Chart *.xlm application/vnd.ms-excel MS Excel Macro *.xls application/vnd.ms-excel MS Excel Spreadsheet *.xlt application/vnd.ms-excel MS Excel Template *.xlw application/vnd.ms-excel MS Excel Workspace *.xml text/xml， application/xml Extensible Markup Language *.zip aplication/zip Compressed Archive