必须提交两次

Question

好的，我是编程新手，我对某些复选框有疑问。
我想存储是否选中了复选框并在按下按钮时显示它。
我正在进行过滤器搜索，因此当有人选择一个复选框时，它只会显示该过滤器。
但是，只有当我提交并选择或取消选择一个复选框两次时它才有效。
我怎样才能让它只需要这样做一次？

<form name="search" action="<? $_SERVER['PHP_SELF']; ?>" method="post">
   <input type="checkbox" name="checkAllMyCB" id="checkAllMyCB" onclick="jqCheckAll2( this.id, 'myCB' )"/>All
   <input name="category[]" type="checkbox" <? if (in_array("art", $_SESSION['category'])) { echo "checked='checked'";  } ?>value="art">Art
   <input name="category[]" type="checkbox" <? if (in_array("church", $_SESSION['category'])) { echo "checked='checked'";  } ?>value="church">Church
   <input name="category[]" type="checkbox" <? if (in_array("education", $_SESSION['category'])) { echo "checked='checked'";  } ?>value="education">Education/Schools
   <input name="category[]" type="checkbox" <? if (in_array("food", $_SESSION['category'])) { echo "checked='checked'";  } ?>value="food">Food
   <input name="category[]" type="checkbox" <? if (in_array("gardening", $_SESSION['category'])) { echo "checked='checked'";  } ?>value="gardening">Gardening
   <input name="category[]" type="checkbox" <? if (in_array("kids", $_SESSION['category'])) { echo "checked='checked'";  } ?>value="kids">Kids
   <input name="category[]" type="checkbox" <? if (in_array("music", $_SESSION['category'])) { echo "checked='checked'";  } ?>value="music">Music
   <input name="category[]" type="checkbox" <? if (in_array("outdoors", $_SESSION['category'])) { echo "checked='checked'";  } ?>value="outdoors">Outdoors
   <input name="category[]" type="checkbox" <? if (in_array("seniors", $_SESSION['category'])) { echo "checked='checked'";  } ?>value="seniors">Seniors
   <input name="category[]" type="checkbox" <? if (in_array("sports", $_SESSION['category'])) { echo "checked='checked'";  } ?> value="sports">Sports/Physical Activity
   <input name="category[]" type="checkbox" <? if (in_array("support", $_SESSION['category'])) { echo "checked='checked'";  } ?>value="support">Club/Support Group
   <input type="submit" name="Go2" id="Go2" value="Go &gt;" />
<? 
$_SESSION['category'] = $_POST['category']; ?>

</form>

Answer 1

您的代码中有两个错误：

1. 您首先显示表单，然后将值设置到SESSION。这应该是相反的方式，因为提交时，您的表单将首先显示，并且仅在设置值之后才显示，这就是为什么您遇到提交两次以查看值的问题。

2. 您没有检查SESSION 变量是否已设置在in_array 之前，这最初会引发错误。与$_POST['category']相同的情况

首先把它放在上面：

<?
if (isset($_POST['category'])){
$_SESSION['category'] = $_POST['category']; }
else
{
    unset($_SESSION['category']);
}
?>

然后将您的表单代码更改为：

<form name="search" action="" method="post">
   <input type="checkbox" name="checkAllMyCB" id="checkAllMyCB" onclick="jqCheckAll2( this.id, 'myCB' )"/>All
   <input name="category[]" type="checkbox" <?php if (isset($_SESSION['category']) && in_array("art", $_SESSION['category'])) { echo "checked='checked'";  } ?> value="art">Art
   <input name="category[]" type="checkbox" <?php if (isset($_SESSION['category']) && in_array("church", $_SESSION['category'])) { echo "checked='checked'";  } ?> value="church">Church
   <input name="category[]" type="checkbox" <?php if (isset($_SESSION['category']) && in_array("education", $_SESSION['category'])) { echo "checked='checked'";  } ?> value="education">Education/Schools
   <input name="category[]" type="checkbox" <?php if (isset($_SESSION['category']) && in_array("food", $_SESSION['category'])) { echo "checked='checked'";  } ?> value="food">Food
   <input name="category[]" type="checkbox" <?php if (isset($_SESSION['category']) && in_array("gardening", $_SESSION['category'])) { echo "checked='checked'";  } ?>value="gardening">Gardening
   <input name="category[]" type="checkbox" <?php if (isset($_SESSION['category']) && in_array("kids", $_SESSION['category'])) { echo "checked='checked'";  } ?> value="kids">Kids
   <input name="category[]" type="checkbox" <?php if (isset($_SESSION['category']) && in_array("music", $_SESSION['category'])) { echo "checked='checked'";  } ?> value="music">Music
   <input name="category[]" type="checkbox" <?php if (isset($_SESSION['category']) && in_array("outdoors", $_SESSION['category'])) { echo "checked='checked'";  } ?> value="outdoors">Outdoors
   <input name="category[]" type="checkbox" <?php if (isset($_SESSION['category']) && in_array("seniors", $_SESSION['category'])) { echo "checked='checked'";  } ?> value="seniors">Seniors
   <input name="category[]" type="checkbox" <?php if (isset($_SESSION['category']) && in_array("sports", $_SESSION['category'])) { echo "checked='checked'";  } ?> value="sports">Sports/Physical Activity
   <input name="category[]" type="checkbox" <?php if (isset($_SESSION['category']) && in_array("support", $_SESSION['category'])) { echo "checked='checked'";  } ?> value="support">Club/Support Group
   <input type="submit" name="Go2" id="Go2" value="Go &gt;" />
</form>