php - GD库中的images()在类里面不起作用，但可以单独使用

Question

我有小问题。我需要存储新闻文章中的一些图像，为此，我使用了这篇文章中的小型调整大小类:Resizing the image in php for viewing purposes only。

<?php
Class resize
{
    // *** Class variables
    private $image;
    private $width;
    private $height;
    private $imageResized;

    function __construct($fileName)
    {
        // *** Open up the file
        $this->image = $this->openImage($fileName);

        // *** Get width and height
        $this->width  = imagesx($this->image);
        $this->height = imagesy($this->image);
    }

    ## --------------------------------------------------------

    private function openImage($file)
    {
        // *** Get extension
        $extension = strtolower(strrchr($file, '.'));

        switch($extension)
        {
            case '.jpg':
            case '.jpeg':
                $img = @imagecreatefromjpeg($file);
                break;
            case '.gif':
                $img = @imagecreatefromgif($file);
                break;
            case '.png':
                $img = @imagecreatefrompng($file);
                break;
            default:
                $img = false;
                break;
        }
        return $img;
    }

    ## --------------------------------------------------------

    public function resizeImage($newWidth, $newHeight, $option="auto")
    {
        // *** Get optimal width and height - based on $option
        $optionArray = $this->getDimensions($newWidth, $newHeight, $option);

        $optimalWidth  = $optionArray['optimalWidth'];
        $optimalHeight = $optionArray['optimalHeight'];


        // *** Resample - create image canvas of x, y size
        $this->imageResized = imagecreatetruecolor($optimalWidth, $optimalHeight);
        imagecopyresampled($this->imageResized, $this->image, 0, 0, 0, 0, $optimalWidth, $optimalHeight, $this->width, $this->height);


        // *** if option is 'crop', then crop too
        if ($option == 'crop') {
            $this->crop($optimalWidth, $optimalHeight, $newWidth, $newHeight);
        }
    }

    ## --------------------------------------------------------

    private function getDimensions($newWidth, $newHeight, $option)
    {

       switch ($option)
        {
            case 'exact':
                $optimalWidth = $newWidth;
                $optimalHeight= $newHeight;
                break;
            case 'portrait':
                $optimalWidth = $this->getSizeByFixedHeight($newHeight);
                $optimalHeight= $newHeight;
                break;
            case 'landscape':
                $optimalWidth = $newWidth;
                $optimalHeight= $this->getSizeByFixedWidth($newWidth);
                break;
            case 'auto':
                $optionArray = $this->getSizeByAuto($newWidth, $newHeight);
                $optimalWidth = $optionArray['optimalWidth'];
                $optimalHeight = $optionArray['optimalHeight'];
                break;
            case 'crop':
                $optionArray = $this->getOptimalCrop($newWidth, $newHeight);
                $optimalWidth = $optionArray['optimalWidth'];
                $optimalHeight = $optionArray['optimalHeight'];
                break;
        }
        return array('optimalWidth' => $optimalWidth, 'optimalHeight' => $optimalHeight);
    }

    ## --------------------------------------------------------

    private function getSizeByFixedHeight($newHeight)
    {
        $ratio = $this->width / $this->height;
        $newWidth = $newHeight * $ratio;
        return $newWidth;
    }

    private function getSizeByFixedWidth($newWidth)
    {
        $ratio = $this->height / $this->width;
        $newHeight = $newWidth * $ratio;
        return $newHeight;
    }

    private function getSizeByAuto($newWidth, $newHeight)
    {
        if ($this->height < $this->width)
        // *** Image to be resized is wider (landscape)
        {
            $optimalWidth = $newWidth;
            $optimalHeight= $this->getSizeByFixedWidth($newWidth);
        }
        elseif ($this->height > $this->width)
        // *** Image to be resized is taller (portrait)
        {
            $optimalWidth = $this->getSizeByFixedHeight($newHeight);
            $optimalHeight= $newHeight;
        }
        else
        // *** Image to be resizerd is a square
        {
            if ($newHeight < $newWidth) {
                $optimalWidth = $newWidth;
                $optimalHeight= $this->getSizeByFixedWidth($newWidth);
            } else if ($newHeight > $newWidth) {
                $optimalWidth = $this->getSizeByFixedHeight($newHeight);
                $optimalHeight= $newHeight;
            } else {
                // *** Sqaure being resized to a square
                $optimalWidth = $newWidth;
                $optimalHeight= $newHeight;
            }
        }

        return array('optimalWidth' => $optimalWidth, 'optimalHeight' => $optimalHeight);
    }

    ## --------------------------------------------------------

    private function getOptimalCrop($newWidth, $newHeight)
    {

        $heightRatio = $this->height / $newHeight;
        $widthRatio  = $this->width /  $newWidth;

        if ($heightRatio < $widthRatio) {
            $optimalRatio = $heightRatio;
        } else {
            $optimalRatio = $widthRatio;
        }

        $optimalHeight = $this->height / $optimalRatio;
        $optimalWidth  = $this->width  / $optimalRatio;

        return array('optimalWidth' => $optimalWidth, 'optimalHeight' => $optimalHeight);
    }

    ## --------------------------------------------------------

    private function crop($optimalWidth, $optimalHeight, $newWidth, $newHeight)
    {
        // *** Find center - this will be used for the crop
        $cropStartX = ( $optimalWidth / 2) - ( $newWidth /2 );
        $cropStartY = ( $optimalHeight/ 2) - ( $newHeight/2 );

        $crop = $this->imageResized;
        //imagedestroy($this->imageResized);

        // *** Now crop from center to exact requested size
        $this->imageResized = imagecreatetruecolor($newWidth , $newHeight);
        imagecopyresampled($this->imageResized, $crop , 0, 0, $cropStartX, $cropStartY, $newWidth, $newHeight , $newWidth, $newHeight);
    }

    ## --------------------------------------------------------

    public function saveImage($savePath, $imageQuality="100")
    {
        // *** Get extension
        $extension = strrchr($savePath, '.');
        $extension = strtolower($extension);

        switch($extension)
        {
            case '.jpg':
            case '.jpeg':
                if (imagetypes() & IMG_JPG) {
                    imagejpeg($this->imageResized, $savePath, $imageQuality);
                }
                break;

            case '.gif':
                if (imagetypes() & IMG_GIF) {
                    imagegif($this->imageResized, $savePath);
                }
                break;

            case '.png':
                // *** Scale quality from 0-100 to 0-9
                $scaleQuality = round(($imageQuality/100) * 9);

                // *** Invert quality setting as 0 is best, not 9
                $invertScaleQuality = 9 - $scaleQuality;

                if (imagetypes() & IMG_PNG) {
                     imagepng($this->imageResized, $savePath, $invertScaleQuality);
                }
                break;

            // ... etc

            default:
                // *** No extension - No save.
                break;
        }

        imagedestroy($this->imageResized);
    }


    ## --------------------------------------------------------

}
?>

但这对我不起作用，我也不知道为什么。
像这样单独尝试一次，循环进行。

for($i = 1; $i <= $imagesCount; $i++){
    $img = @imagecreatefromjpeg($_FILES["files"]["tmp_name"][$i-1]);
    $imgWidth = imagesx($img);
    echo(json_encode($imgWidth));
}

例如，这将输出宽度1903(px)。
当我使用库时，如下所示:

for($i = 1; $i <= $imagesCount; $i++){
    $uploadImage = new resize($_FILES["files"]["tmp_name"][$i-1]);
    //$uploadImage -> resizeImage(1920, 1080, 'landscape');
    //$uploadImage -> saveImage("news/" . $newsID["newsID"] . "/full/" . $i . ".jpg", 100);
}

imagesx()抛出错误

"imagesx() expects parameter 1 to be resource, bool given in..."

同样的错误来自 imagesy()。
我将自动加载程序包括在此类中，但是我认为没有任何问题。有人知道吗，这是怎么了？

Answer 1

所以我终于做到了:
编辑的类(class):

function __construct($fileName, $extension)
            {
                // *** Open up the file
                $this->image = $this->openImage($fileName, $extension);
                echo(json_encode($this->image));
                // *** Get width and height
                $this->width  = imagesx($this->image);
                $this->height = imagesy($this->image);
            }

            ## --------------------------------------------------------

            private function openImage($file, $extension)
            {

                switch($extension)
                {
                    case '.jpg':
                    case '.jpeg':
                        $img = @imagecreatefromjpeg($file);
                        break;
                    case '.gif':
                        $img = @imagecreatefromgif($file);
                        break;
                    case '.png':
                        $img = @imagecreatefrompng($file);
                        break;
                    default:
                        $img = false;
                        break;
                }
                return $img;
            }

编辑 call :

for($i = 1; $i <= $imagesCount; $i++){
    $file = $_FILES["files"]["tmp_name"][$i-1];
    $extension = strtolower(strrchr($_FILES["files"]["name"][$i-1], '.'));

    $uploadImage = new resize($file, $extension);
}

因此，现在我可以在服务器端使用正确的文件名并在客户端使用正确的扩展名在类中创建新对象。
也许会帮助别人。