wordpress管理员中的自定义php表单

Question

这里我在php中创建了一个表单和操作文件，它完美无缺。然后我尝试在wordpress中实现它，表单显示良好，但当我提交它时，它不起作用。任何人都可以帮助我。

//here is my html form
<form action="<?php the_permalink(); ?>" method="post" enctype="multipart/form-data">
  Please choose a file: <input type="file" name="uploadFile"><br>
  <input type="submit" value="Upload File">
</form> 




and here is action area
<?php 
if(isset($_POST['submit'])) {
    $target_dir =  basename( $_FILES["uploadFile"]["name"]);
    $uploadOk=1;
    $contents2 = "";
    if (move_uploaded_file($_FILES["uploadFile"]["tmp_name"], $target_dir)) {
    echo "The file ". basename( $_FILES["uploadFile"]["name"]). " has been uploaded.";

    $CSVfp = fopen($target_dir, "r");
   if($CSVfp !== FALSE) 
   while(!feof($CSVfp)) {
   $data = fgetcsv($CSVfp, 3000, ",");
   $contents2 .=  $data[3]; 
   $var_str = var_export($contents2, true);
   $file = 'new_file.txt';
   $var_str = str_replace("'",",",$var_str);
   $var_str3 = ltrim($var_str,"Pin,");
   $var_str3 = implode(",", str_split($var_str3, 6))." ";
   $var_str4 = str_replace(",,","",$var_str3);
   file_put_contents($file, $var_str4);
} 

}
else {
    echo "Sorry, there was an error uploading your file.";
}

?> 
<form method="get" action="new_file.txt">
<button type="submit">Download!</button>
</form>
<?php
}

?>