在php中有创建缩略图的功能吗?

没有一个函数可以为您创建缩略图,但是有几个函数是GD库的一部分,比如 imagecreatetruecolor imagecopyresampled . 你能做的最好的事情就是从一个教程开始,谷歌知道这里:

http://www.google.co.uk/search?q=gd+php+thumbnail

你有一个GD库函数来创建图片…请按照网址

http://php.net/manual/en/book.image.php

            $sourceAppImgPath = $this->images->absPath($img);
            $file_dimensions = getimagesize($sourceAppImgPath);
            $ImageType = strtolower($file_dimensions['mime']);

                switch(strtolower($ImageType))
                {
                    case 'image/png':
                        $image = imagecreatefrompng($sourceAppImgPath);
                        break;
                    case 'image/gif':
                        $image = imagecreatefromgif($sourceAppImgPath);
                        break;
                    case 'image/jpeg':
                        $image = imagecreatefromjpeg($sourceAppImgPath);
                        break;
                    default:
                        return false; //output error
                }

                    $origWidth = imagesx($image);
                    $origHeight = imagesy($image);
                    $maxWidth = 300;
                    $maxHeight =300;

                    if ($maxWidth == 0)
                        $maxWidth  = $origWidth;

                    if ($maxHeight == 0)
                        $maxHeight = $origHeight;

                    $widthRatio = $maxWidth / $origWidth;
                    $heightRatio = $maxHeight / $origHeight;
                    $ratio = min($widthRatio, $heightRatio);
                    $thumb_width  = (int)$origWidth  * $ratio;
                    $thumb_height = (int)$origHeight * $ratio;