拖放文件上传错误php

Question

我在互联网上观看了许多链接，并且还提到了与此主题相关的每个问题，但没有一个帮助！所以请检查这段代码并告诉我我哪里做错了？

html代码：

 <div class="drop_zone">
  <p>Drop Here</p>
   </div>

<form enctype="multipart/form-data" id="yourregularuploadformId">
   <input type="file" name="files[]" multiple="multiple">
</form>

jQuery和javascript代码：

function handleFiles(droppedFiles) {
var uploadFormData = new FormData($("#yourregularuploadformId")[0]);
    if(droppedFiles.length > 0) { // checks if any files were dropped
    for(var f = 0; f < droppedFiles.length; f++) { // for-loop for each file dropped
     alert(droppedFiles[f]['name']);
        uploadFormData.append("files[]",droppedFiles[f]);  // adding every        file to the form so you could upload multiple files
    }
}

// the final ajax call
alert(uploadFormData);
   $.ajax({
    url : "try.php", // use your target
    type : "POST",
    data : uploadFormData,
    cache : false,
    contentType : false,
    processData : false,
    success : function(ret) {
             alert(ret);
    }
   });
    return false;
}
$(document).ready(function() {
//alert("im in");
$('.drop_zone').bind("dragenter", function(e) { 
  // $('#StatusDrag').html('Drop The files Here...');
});
$('.drop_zone').bind("dragleave", function(e) {
   // $('#StatusDrag').html('Drag and Drop Files Here to Share');
});
$('.drop_zone').bind("dragover", function(e) {
    e.preventDefault();
    return false;
});

$('.drop_zone').bind("drop", function(e) {
    e.preventDefault();
    e.stopPropagation();
    e.originalEvent.preventDefault();
    e.originalEvent.stopPropagation();
   // $('#dragBox, #topDiv').hide();
    var dt = e.originalEvent.dataTransfer;
    var files = dt.files;
    handleFiles(files);
});
});

php代码：

<?php
if(isset($_FILES["files"]))
{
foreach ($_FILES["files"] as $file) 
echo $file['name'];
}
?>