我的网站上有一个选择框和一组radiobuttons。我想在改变radiobutton之后保留选择框的值。我已设法保留选择框中的值，但当我按下其他单选按钮时，我收到此错误
“注意：未定义的索引：第11行的checkGame
注意：未定义的索引：第13行的checkGame“
这是我的代码：
if(isset($_POST['submit']) && $_POST['checkGame'] != 'Any')
{
$game = $_POST['checkGame'];
$sql="SELECT ipaddress, port FROM servers WHERE game=('$game')";
$result=mysqli_query($con,$sql);
$result=mysqli_query($con,$sql);
while ($row=mysqli_fetch_array($result)) {
array_push($serverConnectionArray, ["address" =>$row['ipaddress'], "port" =>$row['port']]);
}
}
if(isset($_POST['playersSort']))
{
if($_POST['playersSort'] == 'Players Descending')
{
uasort($serverArray, function($a, $b) {
return $b['Players'] <=> $a['Players'];
});
}
if($_POST['playersSort'] == 'Players Ascending')
{
uasort($serverArray, function($a, $b) {
return $a['Players'] <=> $b['Players'];
});
}
if($_POST['playersSort'] == 'Max Players Descending')
{
uasort($serverArray, function($a, $b) {
return $b['MaxPlayers'] <=> $a['MaxPlayers'];
});
}
if($_POST['playersSort'] == 'Max Players Ascending')
{
uasort($serverArray, function($a, $b) {
return $a['MaxPlayers'] <=> $b['MaxPlayers'];
});
}
}
<form method="post">
Game:
<select name="checkGame">
<option value="Any"<?php if (isset($game) && $game=="Any") echo "selected";?>>Any</option>
<option value="Garrys Mod"<?php if (isset($game) && $game=="Garrys Mod") echo "selected";?>>Garrys Mod</option>
<option value="Counter Strike Global Offensive"<?php if (isset($game) && $game=="Counter Strike Global Offensive") echo "selected";?>>Counter Strike Global Offensive</option>
<option value="Counter Strike Source"<?php if (isset($game) && $game=="Counter Strike Source") echo "selected";?>>Counter Strike Source</option>
<option value="Team Fortress 2"<?php if (isset($game) && $game=="Team Fortress 2") echo "selected";?>>Team Fortress 2</option>
</select>
<input type="submit" name="submit" value="Filter"/>
</form>
<form action="" method="post">
<input type="radio" name="playersSort" value="Players Descending">Players Descending
<input type="radio" name="playersSort" value="Players Ascending">Players Ascending
<input type="radio" name="playersSort" value="Max Players Descending">Max Players Descending
<input type="radio" name="playersSort" value="Max Players Ascending">Max Players Ascending
<input type="submit" name="submit" value="Sort" />
</form>
答案 0 :(得分：0)
问题在于这一行：
submitSort您将提交按钮设置为submit类型，应该是name
您可以使用submit字段更改提交的名称，但类型需要$_SESSION才能像提交按钮那样工作
我还建议使用 $_SESSION['game'] = "";
if(isset($_POST['submit']) && $_POST['checkGame'] != 'Any')
{
$_SESSION['game'] = $_POST['checkGame'];
}
if ($_SESSION['game'] == "1") { $gameCOD = "selected"; } else $gameCOD = "";
if ($_SESSION['game'] == "2") { $gameBAT = "selected"; } else $gameBAT = "";
<form method="post">
<select name="checkGame">
<option value="1">Any</option>
<option value="2" <?php echo $gameCOD; ?> > COD </option>
<option value="3" <?php echo $gameBAT; ?> > BATTLEFIELD </option>
</select>
<input type="submit" name="submit" value="Filter"/>
</form> varibles在帖子之后存储内容
这是一个简单的例子：
它可能不是最好的方式，它可以显示概念（请修改任何修改）
<div style="display: table; width: 100%; height: 100%; text-align: center;">
<div style="display: table-cell; vertical-align: middle; background:tomato;">square (1:1)</div>
</div>
答案 1 :(得分：0)
在查看代码一段时间并提到需要防止sql注入后，我花了一个小时左右的时间将以下内容拼凑起来 - 最初代码只是为了说明如何使用prepared statement但最终成为你在下面看到的。这些都没有经过测试，因此可能会出现语法错误 - 我怀疑它们会变得很明显。
我的想法似乎没有意义，有两种形式 - 所以它们已合并在这里，sort单选按钮有一个隐藏字段，其值为零 - 这里的想法是，如果没有单选按钮是然后选择的值总是为零 - 这在处理POST数组时很有用。
在完成任何处理之前，每个游戏的名称都在一个数组中定义 - 这允许检查POSTed值是否有效，还允许生成SELECT菜单选项和RADIO按钮动态 - 当与SESSION变量（'game' & 'sort'）结合使用时，允许记住先前提交的值的原始目标，无论按下哪个按钮。
<?php
session_start();
/*
include database connection script or define here
*/
$dbhost = 'localhost';
$dbuser = 'root';
$dbpwd = 'xxx';
$dbname = 'xxx';
$db = new mysqli( $dbhost, $dbuser, $dbpwd, $dbname );
if( !isset( $_SESSION['game'] ) )$_SESSION['game']=false;
if( !isset( $_SESSION['sort'] ) )$_SESSION['sort']=false;
$games=array(
'Any',
'Garrys Mod',
'Counter Strike Global Offensive',
'Counter Strike Source',
'Team Fortress 2'
);
$sorts=array(
0,
'Players Descending',
'Players Ascending',
'Max Players Descending',
'Max Players Ascending'
);
$svrconn=array();
if( $_SERVER['REQUEST_METHOD']=='POST' ){
if( isset( $_POST['submit'], $_POST['checkGame'], $_POST['playersSort'] ) && $_POST['checkGame'] != 'Any' ){
try{
$game = filter_input( INPUT_POST, 'checkGame', FILTER_SANITIZE_STRING );
if( !in_array( $game, $games ) ) throw new Exception('Unknown game');
$_SESSION['game']=$game;
/* create the sql statement with a placeholder `?` */
$sql = 'select `ipaddress`, `port` from `servers` where `game`=?';
/* Attempt to create the `prepared statement` */
$stmt = $db->prepare( $sql );
/* statement was successfully created */
if( $stmt ){
/* bind a variable to the placeholder & execute query */
$stmt->bind_param( 's', $game );
$result=$stmt->execute();
/* Yay! There are results to process */
if( $result ){
$stmt->store_result();
$stmt->bind_result( $ip, $port );
while( $rs=$stmt->fetch() ){
$svrconn[]=array( 'address'=>$ip, 'port'=>$port );
}
$stmt->free_result();
$stmt->close();
$db->close();
} else {/* bogus - no results */
throw new Exception('No results');
}
} else {
throw new Exception('sql query failed to prepare');
}
}catch( Exception $e ){
exit( $e->getMessage() );
}
}
/*
Because of the hidden field with a value of `0` this will not be invoked
unless a radio button is selected.
*/
if( !empty( $_POST['playersSort'] ) ){
try{
$sort=filter_input( INPUT_POST, 'playersSort', FILTER_SANITIZE_STRING );
if( !in_array( $sort, $sorts ) ) throw new Exception('Unknown sort');
$_SESSION['sort']=$sort;
/*
presumably the array ( $svrconn ~ originally $serverConnectionArray or $serverArray? )
is used elsewhere in the page to display content???
apply filter/sorting algorithms
*/
switch( strtolower( $sort ) ){
case 'players descending':
uasort( $svrconn, function($a,$b) {
return $b['Players'] <=> $a['Players'];
});
break;
case 'players ascending':
uasort( $svrconn, function($a,$b) {
return $a['Players'] <=> $b['Players'];
});
break;
case 'max players descending':
uasort( $svrconn, function($a,$b) {
return $b['MaxPlayers'] <=> $a['MaxPlayers'];
});
break;
case 'max players ascending':
uasort( $svrconn, function($a,$b) {
return $a['MaxPlayers'] <=> $b['MaxPlayers'];
});
break;
}
}catch( Exception $e ){
exit( $e->getMessage() );
}
}
}
?>
<!doctype html>
<html>
<head>
<meta charset='utf-8' />
<title>Games n stuff</title>
</head>
<body>
<form method='post'>
<fieldset>
Game:
<select name='checkGame'>
<?php
$html=array();
foreach( $games as $value ){
$selected=trim( strtolower( $_SESSION['game'] ) )==trim( strtolower( $value ) ) ? 'selected=true' : '';
$html[]="<option value='$value' $selected>$value";
}
echo implode( PHP_EOL, $html );
?>
</select>
<input type='submit' name='submit' value='Filter' />
</fieldset>
<fieldset>
<?php
$html=array();
foreach( $sorts as $value ){
$checked=( trim( strtolower( $_SESSION['sort'] ) )==trim( strtolower( $value ) ) ) ? 'checked' : '';
/*
having a hidden field means `playersSort`
will always be present in POSTed data
( unless someone is deliberately hijacking the form )
*/
if( empty( $value ) )$html[]="<input type='hidden' name='playersSort' value='$value' />";
else $html[]="<input type='radio' name='playersSort' value='$value' $checked>$value";
}
echo implode( PHP_EOL, $html );
?>
<input type='submit' name='submit' value='Sort' />
</fieldset>
</form>
</body>
</html>