php產生小圖_php 產生縮圖代碼

# 顯示圖形及串連

 function showdir ($adirectory, $i)

{
  global $browsedir;

  $start = $i;

# 更改 $maxcols 及 $maximages 可改變每一頁顯示的小圖的行數與列數。

  $maxcols = 2;
  $maximages = 6;
  $maximages = $i + ($maximages - 3);

# 更改 $imagemaxwidth 及 $imagemaxheight 可改變顯示小圖的寬度與高度。

  $imagemaxwidth = 100;
  $imagemaxheight = 100;
   
# 計算高度與寬度的比例。

  $imagemaxratio =  $imagemaxwidth / $imagemaxheight;
   
  $ndirectory = sizeof ($adirectory);
  echo (table_start);
  for ($i; $i<=$maximages;)
  {
     echo (row_start);
     for ($icols=1; $icols<=$maxcols; $icols++)
     {
       echo (col_start);
       $imagefilename = $adirectory[++$i];
       if (strlen($imagefilename)>0)
       {
         $imagepath = $browsedir."/".$imagefilename;
         $imagesize = getimagesize ($imagepath);
         if ($imagesize)
         {
           $imagewidth = $imagesize[0];
           $imageheight = $imagesize[1];
           $imageratio = $imagewidth / $imageheight;
           if ($imageratio > $imagemaxratio)
           {
              $imageoutputwidth = $imagemaxwidth;
              $imageoutputheight = ceil ($imagemaxwidth/$imagewidth*$imageheight);
           }
           else if ($imageratio < $imagemaxratio)
           {
              $imageoutputheight = $imagemaxheight;
              $imageoutputwidth = ceil ($imagemaxheight/$imageheight*$imagewidth);
           } else
           {
              $imageoutputwidth = $imagemaxwidth;
              $imageoutputheight = $imagemaxheight;
           }

# 顯示圖形

           echo (a_start.$imagepath.a_close);
           echo (img_start.$imagepath.img_width.$imageoutputwidth.img_height.$imageoutputheight.img_end);
           echo (line_break.$adirectory[$i]);
           echo (a_end);
         }
         echo (col_end);
       }
     }
     echo (row_end);
  }
  echo (table_end);
pagemenu ($browsedir, $ndirectory, $start);

}

function pagemenu ($browsedir, $ndirectory, $pg) {

echo "<br><center><font face="verdana, arial, helvetica, sans-serif" size="1" color="#000033">page:";

$pg_num = 1;

for ($img_num = 0; $img_num <= $ndirectory;) {

    if ($pg == $img_num) {
    echo "<span class="menulink_1"><a href="thumb.php?browsedir=$browsedir&start=$img_num"> *$pg_num</a> <span>";
    } else {
    echo "<span class="menulink_2"><a href="thumb.php?browsedir=$browsedir&start=$img_num"> $pg_num</a> <span>";
    }

# 建立其他頁次的串連, 每頁顯示四張圖, 故頁數 $pg_num 每加 1 , $img_num 就加 4 。

    $pg_num = $pg_num + 1;
    $img_num = $img_num + 4;

}

echo "</font> ";

}

function dirtoarray ($browsedir, $extensions)
{

  $nextensions = sizeof ($extensions);
  $idirectory = 0;
  $directory = dir($browsedir);
   
  while ($entry = $directory->read())
  {
      for ($i=1; $i<=$nextensions; $i++)
      {
         $compare = stristr ($entry, $extensions[$i]);
         if (strlen($compare) == strlen($extensions[$i]))
         {
            $adirectory[++$idirectory] = $entry;
            break;
         }
      }
  }
  $directory->close();
  return $adirectory;
}

#主程式

#變數 $browsedir 為圖形檔案放置的位置。

$browsedir="./images";

# 允許瀏覽的圖形副檔名, 放置於數組中, 可自行增加。

$extensions[1] = "jpeg";
$extensions[2] = "jpg";
$extensions[3] = "gif";
$extensions[4] = "png"; 
showdir (dirtoarray ($browsedir, $extensions), $start);

define ("line_break", "<br>");
define ("table_start", "<table width=600> ");
define ("table_end", "</table> ");
define ("row_start", "  <tr> ");
define ("row_end", "  </tr> ");
define ("col_start", "   <td align=center>       ");
define ("col_end", "    </td> ");
define ("img_start", "<img src=");
define ("img_end", ">");
define ("img_width", " width=");
define ("img_height", " height=");
define ("a_start", '<a href="');
define ("a_close", '">');
define ("a_end", "</a>");
?>