文件上传 4月19日作业

实例

<!--
    1.文件上传的请求类型必须是POST
    2.允许的数据类型必须是：multipart/form-data
    3.如果想在当前的页面处理上传的话，action可能会有三种写法：
    1）.最懒的方式： 当前脚本名
    2). 最死的方法： 当前脚本名
    3).最酷的方法：
-->
<form action="<?php echo htmlspecialchars($_SERVER['PHP_SELF'])?>" method="post" enctype="multipart/form-data">

    <input type ="hidden" name="MAX_FILE_SIZE" value="54288j">
    <fieldset>
        <legend align="center">文件上传</legend>
        <p>
            <strong>选择文件:</strong>
            <input type="file" name="upload">
        </p>
        <p align="center">
            <button type="submit" name="submit">上传</button>
        </p>
    </fieldset>
</form>
<?php
    echo '<hr>long time no see..';

    if($_SERVER['REQUEST_METHOD'] == 'POST')
    {
        //1.检测是否有文件被上传
        if(isset($_FILES['upload'])){
//            2.设置一下允许上传的类型
            $allow = ['image/jpg','image/jpeg','image/png'];
//            3.判断用户上传的文件是否正确
            if(in_array($_FILES['upload']['type'],$allow)){
//                将用户文件上传到指定的临时目录： move_uploaded_file()
                if(move_uploaded_file($_FILES['upload']['tmp_name'],"upload/{$FILES['upload']['name']}")){
                    //上传成功

                }else{

                }
            }
            if($_FILES['upload']['error']>0){
                echo '<p>错误的原因有：</p>'
                switch($_FILES['upload']['error']){
                    case 1:
                        echo '文件太大';
                        break;
                    case 2:
                        echo '文件超过表单中的设置大小';
                        break;
                    case 3:
                        echo '文件只有一部分上传了';
                        break;
                    case 4:
                        echo '没有文件被上传';
                        break;
                    case 6:
                        echo '临时文件夹没有';
                        break;
                    case 8:
                        echo '上传意外中止';
                        break;
                    default:
                        echo '..';
                }
            }
        }
    }

    ?>