如何使用 PHP 在提交的表单上打印复选标记图标?

How to print out a check-mark icon on submitted form using PHP?

如果rowCount == 0,下面的代码将打印出<i class="far fa-star"></i>,如果> 0,将打印出<i class="fas fa-check"></i>,在用户提交表单后,他们将不会能够看到 <i class="fas fa-check"></i> 除非他们刷新页面,在用户提交表单后页面刷新自己,用户需要再刷新一次才能看到 <i class="fas fa-check"></i>:

if ($rowCountFav == 0) {
  $favIcon = '<i class="far fa-star"></i>';
}else{$favIcon = '<i class="fas fa-check"></i>';}

if($_SERVER['REQUEST_METHOD'] == 'POST'){
  if(isset($_POST["fav"])){ 
    if ($rowCountFav == 0) {
      $favorito = $conn->prepare("INSERT INTO `favorito` (user_id, nameItem) VALUES (:user_id, :nameItem)");
      $favorito->bindParam(':user_id', $user_id, PDO::PARAM_INT);
      $favorito->bindParam(':nameItem', $nameItem, PDO::PARAM_STR);
      $favorito->execute();
    }
  } 
}
?>
<form action="" method="post" autocomplete="off">
  <button class="btnSub btnA" type="submit" name="fav" />
    Favorito <?= $favIcon;?>
  </button> <span class="ml-1 mr-2">-</span> 
</form> 

我想要的:我想在用户提交表单后打印出<i class="fas fa-check"></i>

所以我尝试了这个,但没有任何改变:

if($_SERVER['REQUEST_METHOD'] == 'POST'){
  if(isset($_POST["fav"])){ 
    if ($rowCountFav == 0) {
      $favorito = $conn->prepare("INSERT INTO `favorito` (user_id, nameItem) VALUES (:user_id, :nameItem)");
      $favorito->bindParam(':user_id', $user_id, PDO::PARAM_INT);
      $favorito->bindParam(':nameItem', $nameItem, PDO::PARAM_STR);
      $favorito->execute();
    }else{$favIcon = '<i class="fas fa-check"></i>';} ## I just added this line ##
  } 
}

有人可以帮忙吗?

您在更新前检查$rowCountFav。解决方法很简单,切换检查和查询。您还需要在查询后更新变量值:

if($_SERVER['REQUEST_METHOD'] == 'POST'){
  if(isset($_POST["fav"])){ 
    if ($rowCountFav == 0) {
      $favorito = $conn->prepare("INSERT INTO `favorito` (user_id, nameItem) VALUES (:user_id, :nameItem)");
      $favorito->bindParam(':user_id', $user_id, PDO::PARAM_INT);
      $favorito->bindParam(':nameItem', $nameItem, PDO::PARAM_STR);
      $favorito->execute();
      $rowCountFav = 1;
    }
  } 
}

if ($rowCountFav == 0) {
  $favIcon = '<i class="far fa-star"></i>';
} else {
  $favIcon = '<i class="fas fa-check"></i>';
}

?>
<form action="" method="post" autocomplete="off">
  <button class="btnSub btnA" type="submit" name="fav" />
    Favorito <?= $favIcon;?>
  </button> <span class="ml-1 mr-2">-</span> 
</form>