这里来看看php中如何上传图片的
先看代码check_image.php
<html>
<head>
<title></title>
<style type="text/css"></style>
</head>
<body>
<form action="check_image.php" method="post" enctype="multipart/form-data">
<table>
<tr>
<td>Your username</td>
<td><input type="text" name="username" /></td>
</tr>
<tr>
<td>Upload image*</td>
<td><input type="file" name="uploadfile"/></td>
</tr>
<tr>
<td colspan="2">
<small><em> * Acceptable image formats include: GIF, JPG/JPEG and PNG.</em></small>
</td>
</tr>
<tr>
<td>Image Caption</td>
<td><input type="text" name="caption"/></td>
</tr>
<tr>
<td colspan="2" style="text-align:center;">
<input type="submit" name="submit" value="Upload" />
</td>
</tr>
</table>
</form>
</body>
</html>
这里没什么可以说的，都是常见的html标签。
下面看看上传的代码check_image.php，重要的地方都做了注释，整个过程是先根据那个<input type="file"
name="uploadfile"/>指定的图片路径来创建一个图片文件，然后再通过指定的上传路径生成这个图片。
<?php
$db = mysql_connect(‘localhost‘,‘root‘,‘Ctrip07185419‘) or die(‘can not connect to database‘);
mysql_select_db(‘moviesite‘,$db) or die(mysql_error($db));
//上传文件的路径
$dir = ‘D:\Serious\phpdev\test\images‘;
/*
$_FILES:用在当需要上传二进制文件的地方,获得该文件的相关信息
$_FILES[‘userfile‘][‘name‘] 客户端机器文件的原名称。
$_FILES[‘userfile‘][‘type‘] 文件的 MIME 类型，需要浏览器提供该信息的支持，例如“image/gif”
$_FILES[‘userfile‘][‘size‘] 已上传文件的大小，单位为字节
$_FILES[‘userfile‘][‘tmp_name‘] 文件被上传后在服务端储存的临时文件名,注意不要写成了$_FILES[‘userfile‘][‘temp_name‘]很容易写错的，虽然tmp就是代表临时的意思，但是这里用的缩写
$_FILES[‘userfile‘][‘error‘] 和该文件上传相关的错误代码。[‘error‘]
*/
if($_FILES[‘uploadfile‘][‘error‘] != UPLOAD_ERR_OK)
{
switch($_FILES[‘uploadfile‘][‘error‘])
{
case UPLOAD_ERR_INI_SIZE: //其值为 1，上传的文件超过了 php.ini 中 upload_max_filesize 选项限制的值
die(‘The upload file exceeds the upload_max_filesize directive in php.ini‘);
break;
case UPLOAD_ERR_FORM_SIZE: //其值为 2，上传文件的大小超过了 HTML 表单中 MAX_FILE_SIZE 选项指定的值
die(‘The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form.‘);
break;
case UPLOAD_ERR_PARTIAL: //其值为 3，文件只有部分被上传
die(‘The uploaded file was only partially uploaded.‘);
break;
case UPLOAD_ERR_NO_FILE: //其值为 4，没有文件被上传
die(‘No file was uploaded.‘);
break;
case UPLOAD_ERR_NO_TMP_DIR: //其值为 6，找不到临时文件夹
die(‘The server is missing a temporary folder.‘);
break;
case UPLOAD_ERR_CANT_WRITE: //其值为 7，文件写入失败
die(‘The server failed to write the uploaded file to disk.‘);
break;
case UPLOAD_ERR_EXTENSION: //其他异常
die(‘File upload stopped by extension.‘);
break;
}
}$image_caption = $_POST[‘caption‘];
$image_username = $_POST[‘username‘];
$image_date = date(‘Y-m-D‘);
/*getimagesize方法返回一个数组，
$width : 索引 0 包含图像宽度的像素值，
$height : 索引 1 包含图像高度的像素值，
$type : 索引 2 是图像类型的标记：
1 = GIF，2 = JPG， 3 = PNG， 4 = SWF， 5 = PSD， 6 = BMP，
7 = TIFF(intel byte order)，8 = TIFF(motorola byte order)，
9 = JPC，10 = JP2，11 = JPX，12 = JB2，13 = SWC，14 = IFF，15 = WBMP，16 = XBM，
$attr : 索引 3 是文本字符串，内容为“height="yyy" width="xxx"”，可直接用于 IMG 标记
*/list($width,$height,$type,$attr) = getimagesize($_FILES[‘uploadfile‘][‘tmp_name‘]);
//imagecreatefromgXXX方法从一个url路径中创建一个新的图片
switch($type)
{
case IMAGETYPE_GIF:
$image = imagecreatefromgif($_FILES[‘uploadfile‘][‘tmp_name‘]) or die(‘The file you upload was not supported filetype‘);
$ext = ‘.gif‘;
break;
case IMAGETYPE_JPEG:
$image = imagecreatefromjpeg($_FILES[‘uploadfile‘][‘tmp_name‘]) or die(‘The file you upload was not supported filetype‘);
$ext = ‘.jpg‘;
break;
case IMAGETYPE_PNG:
$image = imagecreatefrompng($_FILES[‘uploadfile‘][‘tmp_name‘]) or die(‘The file you upload was not supported filetype‘);
$ext = ‘.png‘;
break;
default :
die(‘The file you uploaded was not a supported filetype.‘);
}$query = ‘insert into images(image_caption,image_username,image_date) values ("‘.$image_caption.‘","‘.$image_username.‘",now())‘;
mysql_query($query , $db) or die(mysql_error($db));
$last_id = mysql_insert_id();
//用写入的id作为图片的名字，避免同名的文件存放在同一目录中
$imagename = $last_id.$ext;
$query = ‘update images set image_filename="‘.$imagename.‘" where image_id=‘.$last_id;
mysql_query($query , $db) or die(mysql_error($db));
//有url指定的图片创建图片并保存到指定目录
switch($type)
{
case IMAGETYPE_GIF:
imagegif($image,$dir.‘/‘.$imagename);
break;
case IMAGETYPE_JPEG:
imagejpeg($image,$dir.‘/‘.$imagename);
break;
case IMAGETYPE_PNG:
imagepng($image,$dir.‘/‘.$imagename);
break;
}
//销毁由url生成的图片
imagedestroy($image);
?><html>
<head>
<title></title>
</head>
<body>
<h1>So how does it feel to be famous</h1>
<p>Here is the picture you just upload to servers</p>
<img src="images/<?php echo $imagename;?>" alt="upload image" />
<table>
<tr>
<td>Image save as:</td><td><?php echo $imagename?></td>
<td>Image type:</td><td><?php echo $ext?></td>
<td>Height:</td><td><?php echo $height?></td>
<td>Width:</td><td><?php echo $width?></td>
<td>Upload date:</td><td><?php echo $image_date?></td>
</tr>
</table>
</body>
</html>
最后写道数据库中的信息如下：
