php - 上传PNG到网站服务器

Question

我看过很多其他主题，并且都尝试过。有人可以帮忙解释一下为什么这个脚本不能上传 PNG 文件吗？正在显示空白 PNG 图像。

$image = $_FILES['file']['tmp_name'];
$image_name = $_FILES['file']['name'];
$ext = pathinfo($image_name, PATHINFO_EXTENSION);

$location = "Profiles/{$user}/Picture/{$image_name}";

$new_image = imagecreatetruecolor(100, 100);

$source_image = imagecreatefrompng($image);

imagealphablending($source_image, false);
imagesavealpha($source_image, true);
imagealphablending($new_image, false);
imagesavealpha($new_image, true);

imagecopyresampled($new_image, $image, 0, 0, 0, 0, 100, 100, $image_width, $image_height);

imagepng($new_image, '../' . $location, 9);

Answer 1

您没有声明 $image_width 或 $image-height 并且您引用的是 $image 而不是 $source_image 在 imagecopyresampled() 中。

我也得到了纯白色图像，但之后我得到了预期的结果:

$image = $_FILES['file']['tmp_name'];
$image_name = $_FILES['file']['name'];
$ext = pathinfo($image_name, PATHINFO_EXTENSION);

$location = "Profiles/{$user}/Picture/{$image_name}";

$new_image = imagecreatetruecolor(100, 100);

$source_image = imagecreatefrompng($image);

// Get the width & height of the uploaded image.
$image_width = imagesx($source_image);
$image_height = imagesy($source_image);

imagealphablending($source_image, false);
imagesavealpha($source_image, true);
imagealphablending($new_image, false);
imagesavealpha($new_image, true);

imagecopyresampled($new_image, $source_image, 0, 0, 0, 0, 100, 100, $image_width, $image_height);

imagepng($new_image, '../' . $location, 9);