PHP 内容类型图像大小 - php content-type image size

php content-type image size

本文关键字：图像类型 PHP | 更新日期: 2023-09-27

我有这段代码来显示用户的头像。

<?php
include("../core/config.php");
if(isset($_GET['uid'])){
if(is_numeric($_GET['uid'])){
    $uid = $_GET['uid'];
}
else{
    exit();
}
$sql="SELECT avatar FROM users_avatar WHERE user_id = '$uid'";  
$row= getRow($sql);
if(!$row){
    $url = "../usravatars/_default/usravatar_default_m.png";
}
else{
$avatar = $row['avatar'];
$url = "../usravatars/$uid/$avatar";
}   
header("Content-Type: image/jpg");
readfile($url);
}
?>

是否可以为正在显示的图像设置自定义大小？

下面是一个动态调整图像大小的示例函数。您可以使用自己的特定宽度/高度或从 get 变量中获取。

function CroppedThumbnail($imgSrc,$thumbnail_width,$thumbnail_height) { //$imgSrc is a FILE - Returns an image resource.
//getting the image dimensions  
list($width_orig, $height_orig) = getimagesize($imgSrc);   
$myImage = imagecreatefromjpeg($imgSrc);
$ratio_orig = $width_orig/$height_orig;
if ($thumbnail_width/$thumbnail_height > $ratio_orig) {
   $new_height = $thumbnail_width/$ratio_orig;
   $new_width = $thumbnail_width;
} else {
   $new_width = $thumbnail_height*$ratio_orig;
   $new_height = $thumbnail_height;
}
$x_mid = $new_width/2;  //horizontal middle
$y_mid = $new_height/2; //vertical middle
$process = imagecreatetruecolor(round($new_width), round($new_height)); 
imagecopyresampled($process, $myImage, 0, 0, 0, 0, $new_width, $new_height, $width_orig, $height_orig);
$thumb = imagecreatetruecolor($thumbnail_width, $thumbnail_height); 
imagecopyresampled($thumb, $process, 0, 0, ($x_mid-($thumbnail_width/2)), ($y_mid-($thumbnail_height/2)), $thumbnail_width, $thumbnail_height, $thumbnail_width, $thumbnail_height);
imagedestroy($process);
imagedestroy($myImage);
return $thumb;
}
//Create the thumbnail
$newThumb = CroppedThumbnail("DSC01088.jpg",$_GET['width'],$_GET['height']);
// And display the image...
header('Content-type: image/jpeg');
imagejpeg($newThumb);

使用header("Content-Type: image/jpg"); readfile($url);，您将原始大小的完整图像发送到浏览器，而不是其他任何内容。

如果要显示同一图像的调整大小版本，请尝试类似

echo '<img src="' . $url . '" width="desired-width" />';

如果要调整原始图像的大小，请查看此页面上的第一个示例 http://php.net/manual/en/function.imagecopyresampled.php