PHP Ajax文件异步上传代码（XMLHttpRequest）例子

文件异步上传通常是通过ajax实现了，也有朋友说使用iframe来实现这个虽然说可以达到目的但不是真正的a异步上传了并且如果浏览器不支持irame那么iframe模仿上传就无效了，下面我们来看一段真正的文件异步上传例子。

php 代码：

$fileName = $_FILES['afile']['name'];
$fileType = $_FILES['afile']['type'];
$fileContent = file_get_contents($_FILES['afile']['tmp_name']);
$dataUrl = 'data:' . $fileType . ';base64,' . base64_encode($fileContent);

$json = json_encode(array(
  'name' => $fileName,
  'type' => $fileType,
  'dataUrl' => $dataUrl,
  'username' => $_REQUEST['username'],
  'accountnum' => $_REQUEST['accountnum']
));

echo $json;

Html 及 JS 代码

 

 
<script><br /> document.querySelector('#afile').addEventListener('change', function(e) {<br /> var file = this.files[0]; <p> var fd = new FormData();<br /> fd.append("afile", file);<br /> // These extra params aren't necessary but show that you can include other data.<br /> fd.append("username", "Groucho");<br /> fd.append("accountnum", 123456); <p> var xhr = new XMLHttpRequest();<br /> xhr.open('POST', 'handle_file_upload.php', true);<br /> <br /> xhr.upload.onprogress = function(e) {<br /> if (e.lengthComputable) {<br /> var percentComplete = (e.loaded / e.total) * 100;<br /> console.log(percentComplete + '% uploaded');<br /> }<br /> }; <p> xhr.onload = function() {<br /> if (this.status == 200) {<br /> var resp = JSON.parse(this.response); <p> console.log('Server got:', resp); <p> var image = document.createElement('img');<br /> image.src = resp.dataUrl;<br /> document.body.appendChild(image);<br /> };<br /> }; <p> xhr.send(fd);<br /> }, false);<br /> </script>