如果您使用一个条件（if.else工作正常），则下面的php脚本可以工作。如果尝试使用if和else-if语句（因为两个条件为true），则第二个条件可以工作，而不是第一个条件。

脚本：

$damage_topdir = "/ids_images/drsIN2/";
$damage_topdir1 = "/ids_images/drsIN1/";
$tmp = split(" ", $displayEntryDatetime);
$date = $tmp[0];
$time = $tmp[1];
$tmp = split("/", $date);
$day = $tmp[0];
$month = $tmp[1];
$year = $tmp[2];
$displayEntryDatetime = $year."-".$month."-".$day." ".$time;
$cam_list = array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16);
if ($cam = 'DRHdrsIN1')
{
foreach ($cam_list as $cam) {
  $timestamp = strtotime($displayEntryDatetime);
  $cam_delta =6;
  $timestamp = $timestamp - $cam_delta;
  for ($i = 0; $i < $cam_delta+20; $i++) {
    $cdate = date("d_m_Y* H_i_s", $timestamp);
    $image_name = "/xampp/htdocs" . $damage_topdir. $cam . "/Cam*" . $cam . "*-" .$cdate . "*";
    foreach (glob($image_name) as $filename) {
      if (file_exists($filename)) {
        $fs_image = str_replace("/xampp/htdocs", "", $filename);
         print "<h3>Camera $cam</h3>";          
        print "<a href='"$fs_image'" target='"_new'"><img src='"$fs_image'" height=240 width=320 /></a>'n";
      }
    }
  $timestamp++;
  }
}
}
elseif($cam = 'DRHdrsIN2') ----> this one executes normally...
{
    foreach ($cam_list as $cam) {
  $timestamp = strtotime($displayEntryDatetime);
  $cam_delta = 6;
  $timestamp = $timestamp - $cam_delta;
  for ($i = 0; $i < $cam_delta+20; $i++) {
    $cdate = date("d_m_Y* H_i_s", $timestamp);
    $image_name = "/xampp/htdocs" . $damage_topdir1. $cam . "/Cam*" . $cam . "*-" .$cdate . "*";
    foreach (glob($image_name) as $filename) {
      if (file_exists($filename)) {
        $fs_image = str_replace("/xampp/htdocs", "", $filename);
        print "<h3>Camera $cam</h3>";          
        print "<a href='"$fs_image'" target='"_new'"><img src='"$fs_image'" height=240 width=320 /></a>'n";
      }
    }
  $timestamp++;
  }
}
}
else {
}
?>