php打造缩略图图片_PHP

php制作缩略图图片
<?phpif (! isset ( $_POST ["submit"] )) {	echo "<?xml version=\"1.0\" encoding=\"UTF-8\"";} else {	if (isset ( $_FILES ["file"] ) || $_POST ["file"] != "") {		function resizeimage($file, $rate = .5) {			$size = getimagesize ( $file );			switch ($size [2]) {				case 1 :					$img = imagecreatefromgif ( $file );					break;				case 2 :					$img = imagecreatefromjpeg ( $file );					break;				case 3 :					$img = imagecreatefrompng ( $file );					break;			}			$srcw = imagesx ( $img );			$srch = imagesy ( $img );			$detw = floor ( $srcw * $rate );			$deth = floor ( $srch * $rate );			$im = imagecreatetruecolor ( $detw, $deth );			$black = imagecolorallocate ( $im, 255, 255, 255 );			imagefilledrectangle ( $im, 0, 0, $detw, $deth, $black );			imagecopyresized ( $im, $img, 0, 0, 0, 0, $detw, $deth, $srcw, $srch );			header ( 'Content-type:image/png' );			imagepng ( $im );			imagedestroy ( $im );			imagedestroy ( $img );		}		resizeimage ( $_FILES ["file"] ["tmp_name"] );	}}?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Insert title here</title><style type="text/css">td {	margin: 0;}</style><script type="text/javascript">function submit(){	obj=document.form1.submit();	return obj;}</script></head><body><form name="form1" method="post" enctype="multipart/form-data"	action="<?php	echo $_SERVER ["PHP_SELF"]?>"><table cellpadding="0" cellspacing="0" border="0"	bordercolordark="#ffffff" bordercolorlight="#0000ff">	<tr>		<td><label>FileUpload : </label></td>		<td><input type="file" name="file"></input></td>		<td><input type="submit" name="submit" value="Submit"></input></td>	</tr></table></form></body></html>