多文件上传：isset（$ _ POST ['submit']）返回False

I am using the following html form code to allow the user to select multiple files for upload.

<form action="uploadFiles.php" method="post" enctype="multipart/form-data">
    <label for="file">Filename:</label>
    <input type="file" name="file[]" multiple /><br>
    <input type="submit" name="submit" value="submit" />
</form>

uploadFiles.php has the following code.

<?php
    echo "uploadFiles.php" . "<br>";
    print_r($_POST);
    if(isset($_POST['submit']))
    {
       echo "Post submit" . "<br>";
       if ($_FILES["file"]["error"][0] > 0)
       {
            echo "Error: " . $_FILES["file"]["error"][0] . "<br>";
        }
        else
        {
              echo "No. files uploaded : ".count($_FILES['file']['name'])."<br>";
              echo "Upload: " . $_FILES["file"]["name"][0] . "<br>";
              echo "Type: " . $_FILES["file"]["type"][0] . "<br>";
              echo "Size: " . ($_FILES["file"]["size"][0] / 1024) . " kB<br>";
              echo "Stored in: " . $_FILES["file"]["tmp_name"][0];
        }
    }
?>

For some reason, isset($_POST['submit']) always returns false. I get the following output

uploadFiles.php
Array( )

You aren't closing the input tags. Particularly, you aren't closing the <input type="file" name="file[]" multiple> tag, so possibly it isn't being added to the form's $_POST array correctly, and is instead being added to the file array. Just a guess.

The problem appears to be related to the size of the files. If the files are 11 MB in size, the post only works with one of them. If I select both $_POST is an empty array. If the files are half that size, the post works with both with the following code.

HTML

 <form action="uploadFiles.php" method="post" enctype="multipart/form-data">
    <label for="file">Filename:</label>
    <input type="file" name="file[]" multiple="multiple"/></br>
    <input type="submit" name="submit[]" value="submit" />
 </form>

uploadFiles.php

<?php
    if(isset($_POST['submit']))
    {
       if ($_FILES["file[]"]["error"] > 0)
       {
            echo "Error: " . $_FILES["file[]"]["error"] . "<br>";
        }
        else
        {
            $numFilesUploaded=count($_FILES['file']['name']);
            echo "No. files uploaded : ".$numFilesUploaded."<br><br>";
            for ($inc=0; $inc<$numFilesUploaded; ++$inc){
                echo "File " . $inc . ": " . $_FILES["file"]["name"][$inc] . "<br>";
                echo "Upload: " . $_FILES["file"]["name"][$inc] . "<br>";
                echo "Type: " . $_FILES["file"]["type"][$inc] . "<br>";
                echo "Size: " . ($_FILES["file"]["size"][$inc] / 1024) . " kB<br>";
                echo "Stored in: " . $_FILES["file"]["tmp_name"][$inc];
                echo "<br><br>";
            }
        }
    }
?>