我在php创建一个下拉列表。当别人选择了一个项目时，我如何放置选中的项目?
我的PHP代码:<form method="POST" action="<?php echo $_SERVER['PHP_SELF']; ?>" >
<select name="app" id="dropdown" value="" onchange="this.form.submit()" ><option>--select-app--</option>
<?php
$sql="select * from application";
$result=mysqli_query($con, $sql) or die("ereor selecting app ".mysqli_error($con));
while($row=mysqli_fetch_array($result))
{
$selected = $row['name'];
echo "<option id=". $row['id']."value = ".$row['id'].">".$row['name']."</option>";
}
echo "</select>";
?>
我想要这样:如果我选择了一个项目，它将显示它被选中。
可以在php中这样做
<form method="POST" action="<?php echo $_SERVER['PHP_SELF']; ?>" >
<select name="app" id="dropdown" value="" onchange="this.form.submit()" >
<option>--select-app--</option>
<?php
$sql="select * from application";
$result=mysqli_query($con, $sql) or die("ereor selecting app ".mysqli_error($con));
$selected_val = $_POST['app']; //Should be $_GET, $_POST, $_SESSION whatever your selected value is
while($row=mysqli_fetch_array($result))
{
if(trim($row['id']) == trim($selected_val)) //<== Change this line
$selected = 'selected="selected"';
else
$selected = '';
echo '<option id="'. $row['id'].'" value="'.$row['id'].'" '. $selected.'>'. $row['name'] .'</option>';
//^Change this line
}
echo "</select>";
?>
在jQuery中，你可以这样做
$('#dropdown').val('<?php echo "My val"; //The value goes here ?>');
假设您希望在表单提交后保留选择，您可以在while循环中执行此操作:
$selected = (isset($_POST['app']) && $_POST['app'] == $row['id'] ? 'selected' : '');
echo "<option id=".$row['id']." value = ".$row['id']." ".$selected.">".$row['name']."</option>";