php 生成图片缩略图-大图生成小图片

/*
    函数：生成缩略图
  MakeBuild("images/a.jpg","news/b.jpg","100");
    参数：
    echo $BuildFile;   原图 带路径
    echo $newFile;    生成的缩略图 带路径
    echo $File_width;   缩略图宽度值
    echo $File_height;   缩略图高度值 (默认为宽度的比例值)
    echo $rate;     缩略图象品质;
 */
 function MakeBuild($BuildFile,$newFile,$File_width,$File_height=0,$rate=1000) {
    if(!is_file($BuildFile)){
   $this->msg("文件 ".$BuildFile." 不是一个有效的图形文件！ 系统无法生成该文件的缩略图！");
   return false;
    }
    $data = GetImageSize($BuildFile);
    switch($data[2]){
  case 1:
   $im = @ImageCreateFromGIF($BuildFile);
   break;
  case 2:
   $im = @ImageCreateFromJPEG($BuildFile);
   break;
  case 3:
   $im = @ImageCreateFromPNG($BuildFile);
   break;
    }
    if(!$im){
   return false;
    }
    else{
   $srcW = ImageSX($im);  # 取得原图宽度;
   $srcH = ImageSY($im); # 取得原图高度;
   $dstX = 0;
   $dstY = 0;
   
  if($File_height==0){
   $File_height = $File_width/$srcW*$srcH;
  }
   
  if ($srcW*$File_height>$srcH*$File_width){
   $fFile_height = round($srcH*$File_width/$srcW);
   $dstY = floor(($File_height-$fFile_height)/2);
   $fFile_width = $File_width;
  }
  else {
   $fFile_width = round($srcW*$File_height/$srcH);
   $dstX = floor(($File_width-$fFile_width)/2);
   $fFile_height = $File_height;
  }
  $ni = ImageCreateTrueColor($File_width,$File_height);
  $dstX = ($dstX<0)?0:$dstX;
  $dstY = ($dstX<0)?0:$dstY;
  $dstX = ($dstX>($File_width/2))?floor($File_width/2):$dstX;
  $dstY = ($dstY>($File_height/2))?floor($File_height/s):$dstY;
  ImageCopyResized($ni,$im,$dstX,$dstY,0,0,$fFile_width,$fFile_height,$srcW,$srcH);
   
  ImageJpeg($ni,$newFile,$rate); # 生成缩略图;
  imagedestroy($im);     # imagedestroy(resource) 释放image关联的内存
    }
 }

<?php

class My_Lib_upfile{

 var $upfile, $upfile_name, $upfile_size;
 # $upfile 临时文件名 $_FILES['tmp_name'] ,$upfile_name 文件名 $_FILES['name'] ,$upfile_size 文件大小$_FILES['size'];

 var $new_upfile_name;   # 上传后的文件名称 ;
 var $fleth, $fileExtent; # 文件扩展名(类型) ;
 var $f1, $f2, $f3;   # 文件保存路径(多级) upfiles/2008-01/08/;
 var $filename;    # 文件(带路径) ;
 var $filepath; #相对路径用来删除文件;
 var $maxSize, $File_type; # 允许上传文件的大小 允许上传文件的类型 ;

 var $BuildFile,$newFile,$File_width,$File_height,$rate;

 function upfileclass($upfile,$upfile_name,$upfile_size){
        $this->upfile = $upfile;
        $this->upfile_name = $upfile_name;
        $this->upfile_size = $upfile_size;
        $this->new_upfile_name = $this->CreateNewFilename($this->upfile_name);
        $this->f1 = "public/upload/images";
        $this->f2 = $this->f1."/".date('Y')."-".date('m');
        $this->f3 = $this->f2."/".date('d');
        $this->filename = $this->f3 . "/" . $this->new_upfile_name;
        $this->maxSize = 5000*1024;    # 文件大小 5000KB
        $this->File_type = "gif/jpg/jpeg/png/bmp"; # 允许上传的文件类型
 }

 # 创建新文件名 (原文件名)
 function CreateNewFilename($file_name){
    $this->fleth = explode(".",$file_name);
    $this->fileExtent = $this->fleth[(int)count($this->fleth)-1]; # 获取文件后缀;
    $tmps教程tr = date('Ymd').rand(0,time()) . "." .$this->fileExtent;    # 创建新文件名;
    return $tmpstr;
 }

 # 检测文件类型是否正确
 function chk_fileExtent(){
    $iwTrue = 0;
    $fle = explode("/",$this->File_type);
    for($i=0; $i < count($fle); $i++){
     if($this->fileExtent == $fle[$i]){
     $iwTrue = (int) $iwTrue + 1;
     }
    }
    if( $iwTrue == 0 ){
  $this->msg("文件不符合 ".$this->File_type." 格式!");
    }
 }

 # 提示错误信息并终止操作
 function msg($Error){
    echo "<script language="javascript教程"> ";
    echo " alert('".$Error."'); ";
    echo " window.history.back(); ";
    echo "</script> ";
    die();
 }

 # 保存文件
 function savefile(){
    $this->chk_fileExtent();
    $this->chk_fileSize();
    $this->CreateFolder( "./".$this->f1 );
    $this->CreateFolder( "./".$this->f2 );
    $this->CreateFolder( "./".$this->f3 );
    return $this->chk_savefile();
 }

 # 检测上传结果是否成功
 function chk_savefile(){
    $copymsg = copy($this->upfile,"./".$this->filename);
    if( $copymsg ){
   return $this->filename;
    }
    else{
   $this->msg("文件上传失败! 请重新上传! ");
    }
 }

 # 创建文件夹
 function CreateFolder($foldername){
    if( !is_dir($foldername) ){
   mkdir($foldername,0777);
    }
 }

 # 检测文件大小
 function chk_fileSize(){
    if( $this->upfile_size > $this->maxSize ){
  $this->msg("目标文件不能大于". $this->maxSize/1024 ." KB");
    }
 }

 # 删除文件($filePath 文件相对路径)
 function Deletefile($filePath){
    if( !is_file($filePath) ){
   return false;
    }
    else{
   $ending = @unlink($filePath);
   return $ending;
    }
 }

}
?>

PHP Date / Time 函数
定义和用法
mktime() 函数返回一个日期的 Unix 时间戳。

参数总是表示 GMT 日期，因此 is_dst 对结果没有影响。

参数可以从右到左依次空着，空着的参数会被设为相应的当前 GMT 值。

语法
mktime(hour,minute,second,month,day,year,is_dst)参数 描述
hour 可选。规定小时。
minute 可选。规定分钟。
second 可选。规定秒。
month 可选。规定用数字表示的月。
day 可选。规定天。
year 可选。规定年。在某些系统上，合法值介于 1901 - 2038 之间。不过在 PHP 5 中已经不存在这个限制了。
is_dst 可选。如果时间在日光节约时间(DST)期间，则设置为1，否则设置为0，若未知，则设置为-1。

自 5.1.0 起，is_dst 参数被废弃。因此应该使用新的时区处理特性。
 
提示和注释
注释：在 PHP 5.1 之前，如果该函数的参数非法，则会返回 false。
例子
mktime() 函数对于日期运算和验证非常有用。它可以自动校正越界的输入：

<?php教程
echo(date("M-d-Y",mktime(0,0,0,12,36,2001)));
echo(date("M-d-Y",mktime(0,0,0,14,1,2001)));
echo(date("M-d-Y",mktime(0,0,0,1,1,2001)));
echo(date("M-d-Y",mktime(0,0,0,1,1,99)));
?>输出：

Jan-05-2002
Feb-01-2002
Jan-01-2001
Jan-01-1999

Example #1 mktime() basic example

<?php
// Set the default timezone to use. Available as of PHP 5.1
date_default_timezone_set('UTC');

// Prints: July 1, 2000 is on a Saturday
echo "July 1, 2000 is on a " . date("l", mktime(0, 0, 0, 7, 1, 2000));

// Prints something like: 2006-04-05T01:02:03+00:00
echo date('c', mktime(1, 2, 3, 4, 5, 2006));
?>
mktime（）是很有用做日期计算和验证，因为它会自动计算出正确的值的范围输入。例如，下面的每一行都会产生字符串“Jan - 01 - 1998”

。

<?php
echo date("M-d-Y", mktime(0, 0, 0, 12, 32, 1997));
echo date("M-d-Y", mktime(0, 0, 0, 13, 1, 1997));
echo date("M-d-Y", mktime(0, 0, 0, 1, 1, 1998));
echo date("M-d-Y", mktime(0, 0, 0, 1, 1, 98));
?>

<?php
$lastday = mktime(0, 0, 0, 3, 0, 2000);
echo strftime("Last day in Feb 2000 is: %d", $lastday);
$lastday = mktime(0, 0, 0, 4, -31, 2000);
echo strftime("Last day in Feb 2000 is: %d", $lastday);
?>

定义和用法
strftime() 函数根据区域设置格式化本地时间／日期。

语法
strftime(format,timestamp)参数 描述
format 可选。规定如何返回结果。
timestamp 可选。
提示和注释
提示：与 gmstrftime() 的行为相同，不同的是返回时间是本地时间。
例子
输出 strftime() 和 gmstrftime() 的结果：

<?php教程
echo(strftime("%b %d %Y %X", mktime(20,0,0,12,31,98)));
echo(gmstrftime("%b %d %Y %X", mktime(20,0,0,12,31,98)));

//输出当前日期、时间和时区
echo(gmstrftime("It is %a on %b %d, %Y, %X time zone: %Z",time()));
?>输出：

Dec 31 1998 20:00:00
Dec 31 1998 19:00:00
It is Wed on Jan 25, 2006, 11:32:10 time zone: W. Europe Standard Time

format  Description Example returned values
Day --- ---
%a An abbreviated textual representation of the day Sun through Sat
%A A full textual representation of the day Sunday through Saturday
%d Two-digit day of the month (with leading zeros) 01 to 31
%e Day of the month, with a space preceding single digits 1 to 31
%j Day of the year, 3 digits with leading zeros 001 to 366
%u ISO-8601 numeric representation of the day of the week 1 (for Monday) though 7 (for Sunday)
%w Numeric representation of the day of the week 0 (for Sunday) through 6 (for Saturday)
Week --- ---
%U Week number of the given year, starting with the first Sunday as the first week 13 (for the 13th full week of the year)
%V ISO-8601:1988 week number of the given year, starting with the first week of the year with at least 4 weekdays, with

Monday being the start of the week 01 through 53 (where 53 accounts for an overlapping week)
%W A numeric representation of the week of the year, starting with the first Monday as the first week 46 (for the 46th week

of the year beginning with a Monday)
Month --- ---
%b Abbreviated month name, based on the locale Jan through Dec
%B Full month name, based on the locale January through December
%h Abbreviated month name, based on the locale (an alias of %b) Jan through Dec
%m Two digit representation of the month 01 (for January) through 12 (for December)
Year --- ---
%C Two digit representation of the century (year divided by 100, truncated to an integer) 19 for the 20th Century
%g Two digit representation of the year going by ISO-8601:1988 standards (see %V) Example: 09 for the week of January 6, 2009
%G The full four-digit version of %g Example: 2008 for the week of January 3, 2009
%y Two digit representation of the year Example: 09 for 2009, 79 for 1979
%Y Four digit representation for the year Example: 2038
Time --- ---
%H Two digit representation of the hour in 24-hour format 00 through 23
%I Two digit representation of the hour in 12-hour format 01 through 12
%l (lower-case 'L') Hour in 12-hour format, with a space preceeding single digits 1 through 12
%M Two digit representation of the minute 00 through 59
%p UPPER-CASE 'AM' or 'PM' based on the given time Example: AM for 00:31, PM for 22:23
%P lower-case 'am' or 'pm' based on the given time Example: am for 00:31, pm for 22:23
%r Same as "%I:%M:%S %p" Example: 09:34:17 PM for 21:34:17
%R Same as "%H:%M" Example: 00:35 for 12:35 AM, 16:44 for 4:44 PM
%S Two digit representation of the second 00 through 59
%T Same as "%H:%M:%S" Example: 21:34:17 for 09:34:17 PM
%X Preferred time representation based on locale, without the date Example: 03:59:16 or 15:59:16
%z Either the time zone offset from UTC or the abbreviation (depends on operating system) Example: -0500 or EST for Eastern

Time
%Z The time zone offset/abbreviation option NOT given by %z (depends on operating system) Example: -0500 or EST for Eastern

Time
Time and Date Stamps教程 --- ---
%c Preferred date and time stamp based on local Example: Tue Feb 5 00:45:10 2009 for February 4, 2009 at 12:45:10 AM
%D Same as "%m/%d/%y" Example: 02/05/09 for February 5, 2009
%F Same as "%Y-%m-%d" (commonly used in database datestamps) Example: 2009-02-05 for February 5, 2009
%s Unix Epoch Time timestamp (same as the time() function) Example: 305815200 for September 10, 1979 08:40:00 AM
%x Preferred date representation based on locale, without the time Example: 02/05/09 for February 5, 2009
Miscellaneous --- ---
%n A newline character (" ") ---
%t A Tab character (" ") ---
%% A literal percentage character ("%") ---

<?php
/*     December 2002 / January 2003
ISOWk  M   Tu  W   Thu F   Sa  Su
----- ----------------------------
51     16  17  18  19  20  21  22
52     23  24  25  26  27  28  29
1      30  31   1   2   3   4   5
2       6   7   8   9  10  11  12
3      13  14  15  16  17  18  19   */

// Outputs: 12/28/2002 - %V,%G,%Y = 52,2002,2002
echo "12/28/2002 - %V,%G,%Y = " . strftime("%V,%G,%Y", strtotime("12/28/2002")) . " ";

// Outputs: 12/30/2002 - %V,%G,%Y = 1,2003,2002
echo "12/30/2002 - %V,%G,%Y = " . strftime("%V,%G,%Y", strtotime("12/30/2002")) . " ";

// Outputs: 1/3/2003 - %V,%G,%Y = 1,2003,2003
echo "1/3/2003 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/3/2003")) . " ";

// Outputs: 1/10/2003 - %V,%G,%Y = 2,2003,2003
echo "1/10/2003 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/10/2003")) . " ";

/*     December 2004 / January 2005
ISOWk  M   Tu  W   Thu F   Sa  Su
----- ----------------------------
51     13  14  15  16  17  18  19
52     20  21  22  23  24  25  26
53     27  28  29  30  31   1   2
1       3   4   5   6   7   8   9
2      10  11  12  13  14  15  16   */

// Outputs: 12/23/2004 - %V,%G,%Y = 52,2004,2004
echo "12/23/2004 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("12/23/2004")) . " ";

// Outputs: 12/31/2004 - %V,%G,%Y = 53,2004,2004
echo "12/31/2004 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("12/31/2004")) . " ";

// Outputs: 1/2/2005 - %V,%G,%Y = 53,2004,2005
echo "1/2/2005 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/2/2005")) . " ";

// Outputs: 1/3/2005 - %V,%G,%Y = 1,2005,2005
echo "1/3/2005 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/3/2005")) . " ";

?>
]
获取指定日期的unix时间戳 strtotime("2009-1-22") 示例如下：
echo strtotime("2009-1-22")  结果：1232553600
说明：返回2009年1月22日0点0分0秒时间戳

二，获取英文文本日期时间 示例如下：
便于比较，使用date将当时间戳与指定时间戳转换成系统时间

(1)打印明天此时的时间戳strtotime("+1 day")
当前时间：echo date("Y-m-d H:i:s",time()) 结果：2009-01-22 09:40:25
指定时间：echo date("Y-m-d H:i:s",strtotime("+1 day")) 结果：2009-01-23 09:40:25

(2)打印昨天此时的时间戳strtotime("-1 day")
当前时间：echo date("Y-m-d H:i:s",time()) 结果：2009-01-22 09:40:25
指定时间：echo date("Y-m-d H:i:s",strtotime("-1 day")) 结果：2009-01-21 09:40:25

(3)打印下个星期此时的时间戳strtotime("+1 week")
当前时间：echo date("Y-m-d H:i:s",time()) 结果：2009-01-22 09:40:25
指定时间：echo date("Y-m-d H:i:s",strtotime("+1 week")) 结果：2009-01-29 09:40:25

(4)打印上个星期此时的时间戳strtotime("-1 week")
当前时间：echo date("Y-m-d H:i:s",time()) 结果：2009-01-22 09:40:25
指定时间：echo date("Y-m-d H:i:s",strtotime("-1 week")) 结果：2009-01-15 09:40:25

(5)打印指定下星期几的时间戳strtotime("next Thursday")
当前时间：echo date("Y-m-d H:i:s",time()) 结果：2009-01-22 09:40:25
指定时间：echo date("Y-m-d H:i:s",strtotime("next Thursday")) 结果：2009-01-29 00:00:00

(6)打印指定上星期几的时间戳strtotime("last Thursday")
当前时间：echo date("Y-m-d H:i:s",time()) 结果：2009-01-22 09:40:25
指定时间：echo date("Y-m-d H:i:s",strtotime("last Thursday")) 结果：2009-01-15 00:00:00

/*
 将日间日期转换成时间时间戳
 strtotime(time,now)参数 描述
 time 规定要解析的时间字符串。
 now 用来计算返回值的时间戳。如果省略该参数，则使用当前时间。
 
 <?php
 echo strtotime("now"), " ";
 echo strtotime("10 September 2000"), " ";
 echo strtotime("+1 day"), " ";
 echo strtotime("+1 week"), " ";
 echo strtotime("+1 week 2 days 4 hours 2 seconds"), " ";
 echo strtotime("next Thursday"), " ";
 echo strtotime("last Monday"), " ";
 ?>
 
 <?php
 $str = 'Not Good';
 
 // previous to PHP 5.1.0 you would compare with -1, instead of false
 if (($timestamp = strtotime($str)) === false) {
  echo "The string ($str) is bogus";
 } else {
  echo "$str == " . date('l dS o F Y h:i:s A', $timestamp);
 }
 ?>
 
 再看strtotime实例
*/
 echo strtotime('2010-2-14'),"<br />";
 echo date('Y-m-d',strtotime('2010-2-14'));
 
 //输出值
 
 1266076800
 2010-02-14
 
 //你应该在strtotime()，你决定什么不能做。例如
 <?php

# on 2/8/2010
date('m/d/y', strtotime('first day')); # 02/01/10
date('m/d/y', strtotime('last day')); # 02/28/10
date('m/d/y', strtotime('last day next month')); # 03/31/10
date('m/d/y', strtotime('last day last month')); # 01/31/10
date('m/d/y', strtotime('2009-12 last day')); # 12/31/09 - this doesn't work if you reverse the order of the year and month
date('m/d/y', strtotime('2009-03 last day')); # 03/31/09
date('m/d/y', strtotime('2009-03')); # 03/01/09
date('m/d/y', strtotime('last day of march 2009')); # 03/31/09
date('m/d/y', strtotime('last day of march')); # 03/31/10
?>