通过AJAX上传文件

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            <div class="grid--cell mb0 mt8">Closed <span title="2013-04-17 03:13:11Z" class="relativetime">7 years ago</span>.</div>
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I want to be able to upload files using AJAX.

I've tried using (JavaScript):

   $("input[type='file']").change(function(){
        var file = document.getElementById("uploadelement").files[0];
        $.ajax({
            url: "upload.php",
            type: "POST",
            beforeSend: function(xhr){
                xhr.setRequestHeader("X_FILENAME", file.name); 
            },
            success: function(data){
                console.log(data);
            }
        });
    });

With (PHP):

<?php

    $fn = (isset($_SERVER['HTTP_X_FILENAME']) ? $_SERVER['HTTP_X_FILENAME'] : false);
    if ($fn) {
        // AJAX call
        file_put_contents(
            'uploads/' . $fn,
            file_get_contents('php://input')
        );
        echo "$fn uploaded";
        exit();
    }

?>

However, i'm having the issue, that the files content isn't show up. I'm not sure whats going wrong. I have found this code on a tutorial so I figured it should be working.

The file is uploaded to the folder but there is no content.

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I don't know with the jQuery $.ajax() call, but this can be achieved by using an XMLHttpRequest, like so:

var file = document.getElementById("uploadelement").files[0];
var form_data = new FormData();
form_data.append("userfile", file);

var xmlhttp = new XMLHttpRequest();
xmlhttp.open("POST", "upload.php");
xmlhttp.send(form_data);

Then in your PHP upload handler (upload.php in here):

move_uploaded_file($_FILES["userfile"]["tmp_name"], "path/to/uploads/" . $_FILES["userfile"]["name"]);

And then the file should already be saved to the desired directory.