Php 如何在文件上载时显示进度条

我正在使用PHPExcel读取一个大型excel文件，并将记录插入数据库。我希望：

从Excel读取数据时显示完成百分比的进度

将行插入/保存到数据库时显示另一个进度条

但我不知道如何才能实现这个进步吧。请给我一个明确的指导，或者如果你知道任何在线教程，请参考它。这是我迄今为止的代码：

if(isset($_POST["submit"]))
{   
$objPHPExcel = PHPExcel_IOFactory::load($_FILES['valuation_roll']['tmp_name']);
$sql = "INSERT INTO roll (year_id, reg_division, farm_number, farm_name, usv, extent, owner_id, position, rate, tax_payable, owner_name, identification_no, address1, nationality) VALUES ";

foreach ($objPHPExcel->getWorksheetIterator() as $worksheet) {
    $worksheetTitle     = $worksheet->getTitle();
    $highestRow         = $worksheet->getHighestRow(); // e.g. 10
    $highestColumn      = $worksheet->getHighestColumn(); // e.g 'F'
    $highestColumnIndex = PHPExcel_Cell::columnIndexFromString($highestColumn);
    $nrColumns = ord($highestColumn) - 64;

    for ($row = 1; $row <= $highestRow; ++ $row) {
        $sql .= "(";
        $values = "";
        $values .= $_POST["year_id"].", ";
        for ($col = 0; $col < $highestColumnIndex; ++ $col) {
            $cell = $worksheet->getCellByColumnAndRow($col, $row);
            $val = $cell->getValue();
            $values = $val.", ";
        }
        $values = substr($values, 0, -1);
        $sql .= "),";
    }
}
$sql = substr($sql, -1);
echo $sql;
}

} });

HTML

您可以使用jquery和ajax实现进度条。如何实现？你能给我讲几步吗。如果是你，你会怎么做呢？我会使用ajax调用php代码，这会给我一个选择来放置进度条形码。您可以像这样附加进度条

$（'idwhereprogressbarappear'）.html（'p align=“center”>
）好的，我们正在取得进展。。我会随时通知你的
  $(function() {
$('form').on('submit', upload_roll);

// Catch the form submit and upload the files
function upload_roll(event)
{
  event.stopPropagation(); // Stop stuff happening
  event.preventDefault(); // Totally stop stuff happening

  // START A LOADING SPINNER HERE

  // Create a formdata object and add the files
  var data = new FormData();
  data.append('file', $('input[type=file]')[0].files[0]);
  $("#progress-bar").addClass("active");
  var progressbar = $( "#progress-bar" ),
      progressLabel = $( "#update" );
  $.ajax({
      url: 'ajax.load.php?year='+$("[name=year_id]").val(),
      type: 'POST',
      data: data,
      contentType: false,
      cache: false,
      processData: false, // Don't process the files
      contentType: false, // Set content type to false as jQuery will tell the server its a query string request
      success: function(data)
      {
         progressbar.progressbar({
           value: false,
           change: function() {

             var ajax_progress = data.split("|");
             var percentage = (ajax_progress[1] / ajax_progress[2]) * 100
             $("#progress-bar").css('width', percentage+"%")
             progressLabel.text(progressbar.progressbar(ajax_progress[0]));

           },
           complete: function() {
             progressLabel.text(ajax_progress[0]);
         }
      });
    }
  });

<div class="progress">
   <div class="progress-bar progress-bar-striped" id="progress-bar" role="progressbar" aria-valuenow="45" aria-valuemin="0" aria-valuemax="100">
    </div>
</div>
<span id="update"></span>