PHP 文件提交表单

好的，我的表格几乎完成了90%（姓名，电子邮件等...

但是，当用户尝试在表单上上传文件时，它只会在我的电子邮件中显示文件的名称，我无法下载它，就像我希望能够下载的那样。你们能帮忙吗？

无需经历所有这些，只需文件输入等...

这是我的HTML表单代码：

<form action="" method=POST id=uploadform autocomplete=off>
 <div class=top-row>
   <div class=field-wrap>
    <input id="sender" type="text" value="<?php echo !empty($name)?$name:''; ?>" placeholder="Your name" name="name" required>
 </div>
 <div class=field-wrap>
    <input id=senderEmail type="email" value="<?php echo !empty($email)?$email:''; ?>" placeholder="Email@domain.com" name="email" required>
 </div>
</div>
 <div class=top-row>
  <div class=field-wrap>
    <input id="sender" type="text" value="<?php echo !empty($videolink)?$videolink:''; ?>" placeholder="Video Link" name="videolink">
 </div>
  <div class=field-wrap>
    <input id="file" type="file" value="<?php echo !empty($file)?$file:''; ?>" name="file">
   </div>
 </div>
    <textarea id=message type="text" placeholder=Description name=message required><?php echo !empty($message)?$message:''; ?></textarea>
<div class="g-recaptcha" data-sitekey="My google site verification would be here"></div>
 <div class=boxcheckauth>
  <span class=checkboxdescription>By uploading, you agree to the TOS and privacy policy.</span>
 </div>
    <?php if(!empty($errMsg)): ?><div class="errMsg"><?php echo $errMsg; ?></div><?php endif; ?>
    <?php if(!empty($succMsg)): ?><div class="succMsg"><?php echo $succMsg; ?></div><?php endif; ?>
  <center><input type=submit name=submit class="button button-block" value="Upload"/></center>
 </form>

这是我的PHP提交代码：

if(isset($_POST['submit'])):
if(isset($_POST['g-recaptcha-response']) && !empty($_POST['g-recaptcha-response'])):
    //your site secret key
    $secret = 'My google site verification would be here';
    //get verify response data
    $verifyResponse = file_get_contents('https://www.google.com/recaptcha/api/siteverify?secret='.$secret.'&response='.$_POST['g-recaptcha-response']);
    $responseData = json_decode($verifyResponse);
    $name = !empty($_POST['name'])?$_POST['name']:'';
    $email = !empty($_POST['email'])?$_POST['email']:'';
    $videolink = !empty($_POST['videolink'])?$_POST['videolink']:'';
    $file = !empty($_POST['file'])?$_POST['file']:'';
    $message = !empty($_POST['message'])?$_POST['message']:'';
    if($responseData->success):
        //contact form submission code
        $to = 'My email would be here';
        $subject = 'Upload form submission';
        $htmlContent = "
            <h1>Upload form submission</h1>
            <p><b>Name: </b>".$name."</p>
            <p><b>Email: </b>".$email."</p>
            <p><b>Video link: </b>".$videolink."</p>
            <p><b>File: </b>".$file."</p>
            <p><b>Message: </b>".$message."</p>
        ";
        // Always set content-type when sending HTML email
        $headers = "MIME-Version: 1.0" . "'r'n";
        $headers .= "Content-type:text/html;charset=UTF-8" . "'r'n";
        // More headers
        $headers .= 'From:'.$name.' <'.$email.'>' . "'r'n";
        //send email
        @mail($to,$subject,$htmlContent,$headers);
        $succMsg = 'Your mail request have submitted successfully.';
        $name = '';
        $email = '';
        $videolink = '';
        $file = '';
        $message = '';
    else:
        $errMsg = 'Robot verification failed, please try again.';
    endif;
else:
    $errMsg = 'Please complete the reCAPTCHA form.';
endif;
else:
    $errMsg = '';
    $succMsg = '';
    $name = '';
    $email = '';
    $videolink = '';
    $file = '';
    $message = '';
endif;