dedecms自动生成缩略图

// 在DedeCMS的配置文件config.php中添加以下配置
$cfg_thumbwidth = 200; // 缩略图宽度
$cfg_thumbheight = 150; // 缩略图高度
$cfg_thumbtype = 2; // 缩略图类型（1：固定尺寸，2：按比例缩放，3：裁剪）

// 在上传图片的处理函数中添加以下代码
if (function_exists('imagecreatetruecolor')) {
    $thumbwidth = $cfg_thumbwidth;
    $thumbheight = $cfg_thumbheight;
    $type = $cfg_thumbtype;

    $img = @imagecreatefromstring($file['tmp_name']);
    if ($img) {
        switch ($type) {
            case 1: // 固定尺寸
                $thumb = imagecreatetruecolor($thumbwidth, $thumbheight);
                imagecopyresampled($thumb, $img, 0, 0, 0, 0, $thumbwidth, $thumbheight, imagesx($img), imagesy($img));
                break;
            case 2: // 按比例缩放
                $ratio = min($thumbwidth / imagesx($img), $thumbheight / imagesy($img));
                $thumbwidth = intval(imagesx($img) * $ratio);
                $thumbheight = intval(imagesy($img) * $ratio);
                $thumb = imagecreatetruecolor($thumbwidth, $thumbheight);
                imagecopyresampled($thumb, $img, 0, 0, 0, 0, $thumbwidth, $thumbheight, imagesx($img), imagesy($img));
                break;
            case 3: // 裁剪
                $x = (imagesx($img) - $thumbwidth) / 2;
                $y = (imagesy($img) - $thumbheight) / 2;
                $thumb = imagecreatetruecolor($thumbwidth, $thumbheight);
                imagecopyresampled($thumb, $img, 0, 0, $x, $y, $thumbwidth, $thumbheight, $thumbwidth, $thumbheight);
                break;
        }
        imagejpeg($thumb, $thumbpath, 80); // 保存缩略图
        imagedestroy($img);
        imagedestroy($thumb);
    }
}