php中使用gd库实现远程图片下载实例

if (!empty($_POST['submit'])){
$url = $_POST['url'];
$pictureName = $_POST['pictureName'];
$img = getPicture($url,$pictureName);
echo '

<img src="'.$img.'">

';
}
function getPicture($url,$pictureName){
if ($url == "") return false;
//获取图片的扩展名
$info = getimagesize($url);
$mime = $info['mime'];
$type = substr(strrchr($mime,'/'),1);
//不同的图片类型选择不同的图片生成和保存函数
switch($type){
case 'jpeg':
$img_create_func = 'imagecreatefromjpeg';
$img_save_func = 'imagejpeg';
$new_img_ext = 'jpg';
break;
case 'png':
$img_create_func = 'imagecreatefrompng';
$img_save_func = 'imagepng';
$new_img_ext = 'png';
break;
case 'bmp':
$img_create_func = 'imagecreatefrombmp';
$img_save_func = 'imagebmp';
$new_img_ext = 'bmp';
break;
case 'gif':
$img_create_func = 'imagecreatefromgif';
$img_save_func = 'imagegif';
$new_img_ext = 'gif';
break;
case 'vnd.wap.wbmp':
$img_create_func = 'imagecreatefromwbmp';
$img_save_func = 'imagewbmp';
$new_img_ext = 'bmp';
break;
case 'xbm':
$img_create_func = 'imagecreatefromxbm';
$img_save_func = 'imagexbm';
$new_img_ext = 'xbm';
break;
default:
$img_create_func = 'imagecreatefromjpeg';
$img_save_func = 'imagejpeg';
$new_img_ext = 'jpg';
}
if ($pictureName == ""){
$pictureName = time().".{$new_img_ext}";
}else{
$pictureName = $pictureName.".{$new_img_ext}";
}
$src_im = $img_create_func($url); //由url创建新图片
$img_save_func($src_im,$pictureName); //输出文件到文件
return $pictureName;
}

?>
<form method="POST" action="">
远程url地址：

文件名称：