dpcwz210393 2011-12-27 16:02
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上传图像文件

I wonder whether someone could help me please.

Through the use of some online tutorials and 'trial and error' I've put together the script below which allows a user to upload image files.

<?php
//define a maxim size for the uploaded images
//define ("MAX_SIZE","100"); 
// define the width and height for the thumbnail
// note that theese dimmensions are considered the maximum dimmension and are not fixed, 
// because we have to keep the image ratio intact or it will be deformed
define ("WIDTH","150"); 
define ("HEIGHT","100"); 

// this is the function that will create the thumbnail image from the uploaded image
// the resize will be done considering the width and height defined, but without deforming the image
function make_thumb($img_name,$filename,$new_w,$new_h)
{
//get image extension.
$ext=getExtension($img_name);
//creates the new image using the appropriate function from gd library
if(!strcmp("jpg",$ext) || !strcmp("jpeg",$ext))
$src_img=imagecreatefromjpeg($img_name);

if(!strcmp("png",$ext))
$src_img=imagecreatefrompng($img_name);

//gets the dimmensions of the image
$old_x=imageSX($src_img);
$old_y=imageSY($src_img);

// next we will calculate the new dimmensions for the thumbnail image
// the next steps will be taken: 
// 1. calculate the ratio by dividing the old dimmensions with the new ones
// 2. if the ratio for the width is higher, the width will remain the one define in WIDTH variable
// and the height will be calculated so the image ratio will not change
// 3. otherwise we will use the height ratio for the image
// as a result, only one of the dimmensions will be from the fixed ones
$ratio1=$old_x/$new_w;
$ratio2=$old_y/$new_h;
if($ratio1>$ratio2) {
$thumb_w=$new_w;
$thumb_h=$old_y/$ratio1;
}
else {
$thumb_h=$new_h;
$thumb_w=$old_x/$ratio2;
}

// we create a new image with the new dimmensions
$dst_img=ImageCreateTrueColor($thumb_w,$thumb_h);

// resize the big image to the new created one
imagecopyresampled($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y); 

// output the created image to the file. Now we will have the thumbnail into the file named by $filename
if(!strcmp("png",$ext))
imagepng($dst_img,$filename); 
else
imagejpeg($dst_img,$filename); 

//destroys source and destination images. 
imagedestroy($dst_img); 
imagedestroy($src_img); 
}

// This function reads the extension of the file. 
// It is used to determine if the file is an image by checking the extension. 
function getExtension($str) {
$i = strrpos($str,".");
if (!$i) { return ""; }
$l = strlen($str) - $i;
$ext = substr($str,$i+1,$l);
return $ext;
}

// This variable is used as a flag. The value is initialized with 0 (meaning no error found) 
//and it will be changed to 1 if an error occurs. If the error occures the file will not be uploaded.
$errors=0;
// checks if the form has been submitted
if(isset($_POST['Submit']))
{

// cleaning title field 
$title = 'title'; 

if ($title == '') // if title is not set 
$title = '(No Title Provided)';// use (empty title) string 

//reads the name of the file the user submitted for uploading
$image=$_FILES['image']['name'];
// if it is not empty
if ($image) 
{
// get the original name of the file from the clients machine
$filename = stripslashes($_FILES['image']['name']);

// get the extension of the file in a lower case format
$extension = getExtension($filename);
$extension = strtolower($extension);
// if it is not a known extension, we will suppose it is an error, print an error message 
//and will not upload the file, otherwise we continue
if (($extension != "jpg") && ($extension != "jpeg") && ($extension != "png")) 
{
echo '<b> Error! </b> - The image that you attempted to upload is not in the correct format. The file format <b> must </b> be one of the following: <b> "jpg", "jpeg" </b> or <b> "png" </b>. Please try again.';
$errors=1;
}
else
{
// get the size of the image in bytes
// $_FILES[\'image\'][\'tmp_name\'] is the temporary filename of the file in which the uploaded file was stored on the server
$size=getimagesize($_FILES['image']['tmp_name']);
$sizekb=filesize($_FILES['image']['tmp_name']);

//compare the size with the maxim size we defined and print error if bigger
if ($sizekb > 1150000)
{
echo '<b> Error! </b> - The file that you are attempting to upload is greater than the prescribed <b> 1MB </b> limit. Please try again.';
$errors=1;
}

//we will give an unique name, for example the time in unix time format
$image_name=$title.'.'.$extension;
//the new name will be containing the full path where will be stored (images folder)
$newname="images/".$image_name;
$copied = copy($_FILES['image']['tmp_name'], $newname);
//we verify if the image has been uploaded, and print error instead
if (!$copied) 
{
echo '<b> Error! </b> Your file has not been loaded';
$errors=1;
}
else
{
// the new thumbnail image will be placed in images/thumbs/ folder
$thumb_name='images/thumbs/'.$image_name;
// call the function that will create the thumbnail. The function will get as parameters 
//the image name, the thumbnail name and the width and height desired for the thumbnail
$thumb=make_thumb($newname,$thumb_name,WIDTH,HEIGHT);
}} }}

//If no errors registred, print the success message and show the thumbnail image created
if(isset($_POST['Submit']) && !$errors) 
{
echo '<br><b> Success! </b> - Your image has been uploaded</br>';
echo '<img src="'.$thumb_name.'">';
}

?>
<!-- next comes the form, you must set the enctype to "multipart/form-data" and use an input type "file" -->

<form name="newad" method="post" enctype="multipart/form-data" action="">
<table>
<tr><td><input type="text" name="title" ></td></tr>
<tr><td><input type="file" name="image" ></td></tr>
<tr><td><input name="Submit" type="submit" value="Upload image"></td></tr>
</table> 
</form>

I appreciate that this may be a real beginners question, but I'm having problems in saving the 'Title' provided by the user as a form of identifying the image file. If the user doesn't provide a 'Title', the words '(No Title Provided)' are saved as the filename, and I can get this to work correctly, but if I complete the 'Title' text field, the value isn't pulled and inserted as the filename.

I know that the answer lies within this piece of code:

$title = 'title'; 

if ($title == '') // if title is not set 
$title = '(No Title Provided)';// use (empty title) string 

But I've tried all manner of ways to try and overcome this without any luck. I just wondered whether someone could perhaps take a look at this please and let me know where I've gone wrong.

Many thanks and kind regards.

  • 写回答

2条回答 默认 最新

  • doujiaoang69440 2011-12-27 16:12
    关注

    Thanks to @ThatOtherPerson, I realised that I was not capturing the 'Title' value. The solution is

    $title = ($_POST['title']); 
    
    if ($title == '') // if title is not set 
    $title = '(No Title Provided)';// use (empty title) string 
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
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