javascript - 未定义索引 : avatar

Question

这个问题已经有答案了:

"Notice: Undefined variable", "Notice: Undefined index", "Warning: Undefined array key", and "Notice: Undefined offset" using PHP (29 个回答)

已关闭 5 年前。

我有这段代码来上传头像。它工作正常，但如果我提交带有空头像的表单，我会得到 undefined index 头像。第一个代码是 php 代码，然后是 Html 代码，最后一个代码是文件输入代码。感谢各位 friend 的帮助。

    if(isset($_POST['submit'])){

        $adminID = $_SESSION['adminID'];

        if($_POST['avatar'] == ""){
            $error[] = "Please Select a Picture!";
            }

        $type = explode('.', $_FILES['avatar']['name']);
        $type = $type[count($type)-1];      
        $url = 'assets/images/users/'.$_SESSION['username'].'.'.$type;
        if(in_array($type, array('gif', 'jpg', 'jpeg', 'png', 'JPG', 'GIF', 'JPEG', 'PNG'))) {
            if(is_uploaded_file($_FILES['avatar']['tmp_name'])) {           
                if(move_uploaded_file($_FILES['avatar']['tmp_name'], $url)) {

                    try {   //insert into database with a prepared statement
                            $stmt = $db->prepare("UPDATE admin SET avatar = '$url' WHERE adminID =  $adminID");
                            $stmt->execute(array(
                                $adminID
                            ));

                            echo '<META HTTP-EQUIV="Refresh" Content="0; URL='.$location.'">';
                            exit;
                        } 
                    //else catch the exception and show the error.
                    catch(PDOException $e) {
                            $error[] = $e->getMessage();
                        }                       
                }       
            } 
        }   
    }
?>

下面是文件输入的 HTML 代码，用户将用它来选择头像

    <div class="col-sm-4 text-center">
        <?php
            if(isset($error)){
                foreach($error as $error){
                    echo '<p class="btn btn-warning">'.$error.'</p>';

                }                                           
            }
        ?> 
            <input type="file" id="avatar" name="avatar" class="file" data-preview-file-type="any" />
        </div>
        <button type="submit" id="submit" name="submit" class="btn btn-success pull-right">Save <span class="fa fa-floppy-o fa-right"></span></button>

这是我的文件输入插件初始化代码

<script>
    var btnCust = '<button type="button" class="btn btn-secondary" title="Add picture tags" ' + 
        'onclick="alert(\'Call your custom code here.\')">' +
        '<i class="glyphicon glyphicon-tag"></i>' +
        '</button>'; 
    $("#avatar").fileinput({
        overwriteInitial: true,
        maxFileSize: 1500,
        showClose: false,
        showCaption: false,
        showBrowse: false,
        browseOnZoneClick: true,
        removeLabel: '',
        removeIcon: '<i class="fa fa-trash-o"></i>',
        removeTitle: 'Cancel or Delete Selection',
        elErrorContainer: '#kv-avatar-errors-2',
        msgErrorClass: 'alert alert-block alert-danger',
        defaultPreviewContent: '<img src="" alt=""><h6 class="text-muted">Click to select</h6>',
        layoutTemplates: {main2: '{preview} ' +  btnCust + ' {remove} {browse}'},
        allowedFileExtensions: ["jpg", "png", "gif"]
    });
</script>

Answer 1

您已将 avatar 字段作为 $_POST 数组的成员引用一次，然后又作为 $_FILES 数组的成员引用。

只需使用以下内容更改 if 条件即可消除错误并实现您想要执行的逻辑。

if($_FILES['avatar']['name'] == ""){
     $error[] = "Please Select a Picture!";
}