使用ajax和JavaScript函数上传文件[重复]

Need a big favor! I'm trying to send uploaded file using JavaScript & Ajax, however not getting any success.

I want that when I upload the file, it will call the function myFunction(), and send the file to the PHP path(ajax.php) I've set.

Below is the code I've so far.

<script>
   function myFunction() {
      var x = document.getElementById("up");
      $.ajax({
         type: 'GET',
         url: 'ajax.php',
         data: {},
         beforeSend: function() {},
         success: function(data) {
            alert(data);
         }
      });
   }
</script>
<input type="file" name="images" id="up" onchange="myFunction()" />

</div>

Uploading files with Jquery and Ajax is a little tricky, but it is something that is already fairly well documented. A quick google search returns a fairly good example of this https://abandon.ie/notebook/simple-file-uploads-using-jquery-ajax

The most important part is obtaining the formdata. Javascript can grab the file elements and build a FormData object from it. From the example above

$('input[type=file]').on('change', prepareUpload);
function prepareUpload(event)
{
  files = event.target.files;
}

You can then build the form object and use that as the data component of your ajax request.

var data = new FormData();
$.each(files, function(key, value)
{
    data.append(key, value);
});

When you upload a field with ajax, you have to create a formData object, then you can change the attribute data: Try this:

<script>
    function myFunction() {
        var form = $('form')[0]; 
        var formData = new FormData(form);

        $.ajax({
            type: 'POST',
            url: 'ajax.php',
            data: formData,
            contentType: false,
            processData: false,
            success: function(data) {
                alert(data);
            }
        });

    }
</script>

<form method="POST">
    <input type="file" name="images" id="up" onchange="myFunction()" />
</form>

If you only have one image and are using your input in a form, you can get the object by using FormData().And sending it when you click on a submit button. When passing it to AJAX use the variable (formdata) to tell AJAX what data to send. Hope this helps:

  function myFunction(event){
       event.preventDefault();
      var formdata = new FormData();
     formdata.append("images[]",images);
      $.ajax({
        type: 'GET',
        url: 'ajax.php',
        data: formdata,
        beforeSend: function() {},
        success: function(data) {
           alert(data);
       }
     });
   }

If you are uploading multiple images:

  <form id="yourform" method="POST" enctype="multipart/form-data">
      <input type="file" name="images[]" id="up" onchange="myFunction()" 
    multiple/>
   </form>

Try this, THis is my working code.

function myFuction(){
        var form = $("#formId").get(0); 
        e.preventDefault(); //keeps the form from behaving like a normal (non-ajax) html form

        $.ajax({
            url: ajax.php,
            type: 'POST',
            data: new FormData(form),
            dataType: 'json',
            mimeType: 'multipart/form-data',
            processData: false,
            contentType: false,
            success: function (response) {
                   alert('success');
            },
            error: function (data) {
                   alert('error');
            }
        });
}

<form id="formId" method="POST">
    <input type="file" name="images" id="up" onchange="myFunction()" />
</form>