如何在保存上传图片时添加refno前缀至文件名？

我的网站有随机生成的refno编号（示例：20221234），同时具备文件上传功能。目前上传的图片会以原文件名（如cat.png）保存到指定路径，我想在保存图片时把refno加在文件名前缀，变成20221234cat.png的格式，请问是否可行？

现有代码 #

PHP上传代码 #

<?php    
$refno = isset ($_GET['refno'])? $_GET['refno']:'';
$file = isset($_FILES["file"]["tmp_name"])? $_FILES["file"]["tmp_name"] : "";
$file_size = isset($_FILES["file"]["size"])? $_FILES["file"]["size"] : "";
$file_name = isset($_FILES["file"]["name"])? $_FILES["file"]["name"] : "";
if(isset($_POST['submit']))
{
    $dataDir = "//sgewsnant21.amk.st.com/ews/web/webspool/temp/visualdefectreport/";
             
    if ($file_size <= 0)
    {
        echo "<script language=\"javascript\" type=\"text/javascript\">";
        echo "  alert('No picture attached!')";
        //echo $refno;
        echo "</script>";
    }
    else
    {
        if(stristr($file_name, ".png")){
            $connection = mysqli_connect($apews_db_apews2, $apews_db_usr, $apews_db_pwd) or die ("Unableeeee to connect!");
            $dest = $dataDir.$file_name;
            if(move_uploaded_file($file,$dest))
            {
                echo "<script language=\"javascript\" type=\"text/javascript\">";
                echo "  alert('Visual Defect Report and pictures are successfully submitted!')";
                //echo $refno;
                echo "</script>";
            }
        }
        else if(stristr($file_name, ".jpg")){
            $connection = mysqli_connect($apews_db_apews2, $apews_db_usr, $apews_db_pwd) or die ("Unableeeee to connect!");
            $dest = $dataDir.$file_name;
            if(move_uploaded_file($file,$dest))
            {
                echo "<script language=\"javascript\" type=\"text/javascript\">";
                echo "  alert('Visual Defect Report and pictures are successfully submitted!')";
                //echo $refno;
                echo "</script>";
            }
        }
        else if(stristr($file_name, ".jpeg")){
            $connection = mysqli_connect($apews_db_apews2, $apews_db_usr, $apews_db_pwd) or die ("Unableeeee to connect!");
            $dest = $dataDir.$file_name;
            if(move_uploaded_file($file,$dest))
            {
                echo "<script language=\"javascript\" type=\"text/javascript\">";
                echo "  alert('Visual Defect Report and pictures are successfully submitted!')";
                //echo $refno;
                echo "</script>";
            }
        }
    }
}
    
$file_name= "//sgewsnant21.amk.st.com/ews/web/webspool/temp/visualdefectreport/" . $refno.$file_name;

flush();
mysqli_close($conn);
?>        

前端生成refno代码 #

<script type="text/javascript">
    const now = new Date();
    let randomNum = '';
    randomNum += Math.round(Math.random() * 9);
    randomNum += Math.round(Math.random() * 9);
    randomNum += now.getTime().toString().slice(-2);
    window.onload = function () {
        document.getElementById("refno").value = `${new Date().getFullYear()}${randomNum}`;
    }
</script>

<label class="control-label col-sm-4" for="refno">REF nos :</label>
<div class="col-sm-4">
    <p class="form-control-static" style="margin-top: -6px;">
        <input type="text" class="form-control" id="refno" name="refno" value="<?php echo $refno;?>" disabled>
    </p>
</div>

解决方案 #

完全可行，只需修改几个关键节点，同时优化现有代码的冗余问题：

1. 修正refno的获取逻辑 #

当前代码用$_GET['refno']获取值，但表单提交是POST方法，且前端refno输入框为disabled状态——disabled的输入框不会随表单提交数据，需做两处修改：

• 前端：将<input ... disabled>改为<input ... readonly>，确保值能提交且用户无法修改
• 后端：将$refno = isset ($_GET['refno'])? $_GET['refno']:'';改为$refno = isset($_POST['refno']) ? trim($_POST['refno']) : '';

2. 拼接refno到文件名前缀 #

在生成文件保存路径$dest时，直接将$refno与原文件名拼接，替换原代码中的$dataDir.$file_name为$dataDir . $refno . $file_name即可得到目标格式。

3. 优化冗余代码 #

原代码对不同图片后缀做了重复逻辑，可合并判断；同时数据库连接只需执行一次，无需在每个分支重复编写。

完整修改后的PHP代码 #

<?php    
$refno = isset($_POST['refno']) ? trim($_POST['refno']) : '';
$file = isset($_FILES["file"]["tmp_name"]) ? $_FILES["file"]["tmp_name"] : "";
$file_size = isset($_FILES["file"]["size"]) ? $_FILES["file"]["size"] : "";
$file_name = isset($_FILES["file"]["name"]) ? $_FILES["file"]["name"] : "";

if(isset($_POST['submit']))
{
    $dataDir = "//sgewsnant21.amk.st.com/ews/web/webspool/temp/visualdefectreport/";
             
    if ($file_size <= 0)
    {
        echo "<script language='javascript'>alert('No picture attached!');</script>";
    }
    else
    {
        // 定义允许的图片后缀集合
        $allowedExts = ['.png', '.jpg', '.jpeg'];
        $fileExt = strtolower(strrchr($file_name, '.'));
        
        // 判断文件后缀是否合法
        if(in_array($fileExt, $allowedExts)){
            // 仅连接一次数据库
            $connection = mysqli_connect($apews_db_apews2, $apews_db_usr, $apews_db_pwd) or die ("Unable to connect!");
            
            // 拼接refno到文件名前缀
            $dest = $dataDir . $refno . $file_name;
            
            if(move_uploaded_file($file, $dest))
            {
                echo "<script language='javascript'>alert('Visual Defect Report and pictures are successfully submitted!');</script>";
            }
            
            // 关闭数据库连接
            mysqli_close($connection);
        } else {
            echo "<script language='javascript'>alert('Only PNG/JPG/JPEG files are allowed!');</script>";
        }
    }
}

flush();
?>        

4. 修改后的前端代码（仅调整输入框属性） #

<script type="text/javascript">
    const now = new Date();
    let randomNum = '';
    randomNum += Math.round(Math.random() * 9);
    randomNum += Math.round(Math.random() * 9);
    randomNum += now.getTime().toString().slice(-2);
    window.onload = function () {
        document.getElementById("refno").value = `${new Date().getFullYear()}${randomNum}`;
    }
</script>

<label class="control-label col-sm-4" for="refno">REF nos :</label>
<div class="col-sm-4">
    <p class="form-control-static" style="margin-top: -6px;">
        <input type="text" class="form-control" id="refno" name="refno" value="<?php echo $refno;?>" readonly>
    </p>
</div>

关键说明 #

• readonly替代disabled：保证refno值能随表单提交，同时限制用户修改
• 文件名拼接：直接在原文件名前追加$refno，即可生成20221234cat.png格式的文件名
• 合并后缀判断：减少重复代码，新增非法文件类型提示
• 修复数据库连接错误：原代码最后使用未定义的$conn关闭连接，修改为正确的$connection变量

内容的提问来源于stack exchange，提问作者Travis Sloap