网页上查看上传图片

1.在form中，必须有 enctype 提交方法必须是POST

 <form class="formAjax" enctype="multipart/form-data" method="POST" id="modelform">

2.上传图片，可以在网页中查看

                <tr rowspan='4'>
                    <?php if ($url_method =='create'): ?>
                        <img src="/images/photo-empty.jpg" alt=""
                             style="110px;height:139px;float:left;padding-left:210px;" id="photopath">
                    <?php else: ?>
                        <img src="" alt=""
                             style="110px;height:139px;float:left;padding-left:210px;" id="photopath">
                    <?php endif; ?>
                </tr>
                <tr>
                    <p class="short-input ue-clear">
                        <input type="file" name="addfile" id="proimg" style="position: relative;left: 145px;"
                       onchange="Preview(this,'photopath','divphotopath');">
                    </p>
                </tr>

     js代码

 function Preview(obj, obj1, obj2) {
        if (document.all) {
            $("#" + obj1).css("width", "0px");
            $("#" + obj1).css("height", "0px");
            $("#" + obj2).css("display", "block");
            document.getElementById('' + obj2 + '').filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = obj.value;
        } else {
            $('#' + obj1).show();
            var file = obj, objectURL = window.URL.createObjectURL(file.files[0]);
            $('#' + obj1).attr("src", objectURL);
        }
    }

3.不能用ajax传递，必须用ajaxSubmit进行传递

 $("#modelform").ajaxSubmit({
}）

 4.php后端代码

            $config['upload_path'] = FCPATH . 'uploads/userphoto/';
            $config['allowed_types'] = 'png|jpg|jpeg';
            $config['max_size'] = '2000000';
            $config['overwrite'] = FALSE;
            $config['encrypt_name'] = TRUE;
            $CI =& get_instance();
            $CI->load->library('upload', $config);
            if ($_FILES['addfile']['name'] != '') {
                if ($CI->upload->do_upload('addfile')) {
                    $str = $CI->upload->data();
                    $file = realpath(FCPATH . 'uploads/userphoto/');
                    if (!is_dir($file)) mkdir($file);
                    $filename = $datainfo[$this->mydb->getKeyId()] . date("YmdHis") . $str['file_ext'];
                    $file = $file . '/' . $filename;
                    if (is_file($file)) unlink($file);
                    copy($str['full_path'], $file);
                    unlink($str['full_path']);
                    $file = "http://" . $_SERVER["HTTP_HOST"] . '/uploads/userphoto/' . $filename;
                    $datainfo ['photopath'] = $file;
                } else {
                    $result = Ousuclass::getJsonResult();
                    $result['success'] = FALSE;
                    $result['msg'] = '上传文件错误!';
                    echo json_encode($result);
                    exit;
                }
            }