[JavaScript知识库]文件上传限制大小限制类型

<input type="file" name="noticeFileName" style="width: 400px;" onchange="fileChange(this);" />

<script type="text/javascript">

     function fileChange(target) {

         var filetypes = [".zip", ".ZIP",".pdf",".PDF"];
         var filepath = target.value;

         if (filepath) {
             var isnext = false;
             var fileend = filepath.substring(filepath.lastIndexOf("."));
             if (filetypes && filetypes.length > 0) {
                 for (var i = 0; i < filetypes.length; i++) {
                     if (filetypes[i] == fileend) {
                         isnext = true;//allowed file
                         break;
                     }
                 }
             }
             if (!isnext) {
                 alert("不接受此文件类型！");
                 target.value = "";
                 return false;
             }
         } else {
             return false;
         }

        var filemaxsize = 1024 * 1024*5;
        var fileSize = target.files[0].size;

        if (fileSize > filemaxsize) {

             alert("附件大小不能大于" + (filemaxsize /1024/1024)+ "MB！");
             target.value = "";
             return false;
        }
        if (fileSize <= 0) {
             alert("附件大小不能为0M！");
             target.value = "";
             return false;
         }
     }
 </script>