php+js实现异步图片上传实例分享

upload.php

<?php
if(isset($_FILES["myfile"]))
{
$ret = array();
$uploadDir = 'images'.DIRECTORY_SEPARATOR.date("Ymd").DIRECTORY_SEPARATOR;
$dir = dirname(__FILE__).DIRECTORY_SEPARATOR.$uploadDir;
file_exists($dir) || (mkdir($dir,0777,true) && chmod($dir,0777));
if(!is_array($_FILES["myfile"]["name"])) //single file
{
$fileName = time().uniqid().'.'.pathinfo($_FILES["myfile"]["name"])['extension'];
move_uploaded_file($_FILES["myfile"]["tmp_name"],$dir.$fileName);
$ret['file'] = DIRECTORY_SEPARATOR.$uploadDir.$fileName;
}
echo json_encode($ret);
}
?>

index.html

<!DOCTYPE html>
<html>
<head>
    <title>Html5 Ajax 上传文件</title>
    <meta charset="utf-8">
<script type="text/javascript">

    var xhr;
    function createXMLHttpRequest()
    {
        if(window.ActiveXObject)
        {
            xhr = new ActiveXObject("Microsoft.XMLHTTP");
        }
        else if(window.XMLHttpRequest)
        {
            xhr = new XMLHttpRequest();
        }
    }

    function UpladFile()
    {
        var fileObj = document.getElementById("file").files[0];
        var FileController = 'upload.php';
        var form = new FormData();
        form.append("myfile", fileObj);
        createXMLHttpRequest();
        xhr.onreadystatechange = handleStateChange;
        xhr.open("post", FileController, true);
        xhr.send(form);
    }

    function handleStateChange()
    {
        if(xhr.readyState == 4)
        {
            if (xhr.status == 200 || xhr.status == 0)
            {
                var result = xhr.responseText;
                var json = eval("(" + result + ")");
                alert('图片链接:\n'+json.file);
            }
        }
    }

</script>

<style>
    .txt{ height:28px; border:1px solid #cdcdcd; width:670px;}
    .mybtn{ background-color:#FFF; line-height:14px;vertical-align:middle;border:1px solid #CDCDCD;height:30px; width:70px;}
    .file{ position:absolute; top:0; right:80px; height:24px; filter:alpha(opacity:0);opacity: 0;width:260px }
</style>
</head>

<body>
<div>
    <label>图片</label>
    <br/>
    <input type='text' name='textfield' id='textfield' class='txt' />
    <span onclick="file.click()" >浏览...</span>
    <input type="file" name="file" id="file" size="28" onchange="document.getElementById('textfield').value=this.value" />
    <span onclick="UpladFile()">上传</span>
</div>
</body>

</html>

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